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Churchland MM. When preparation pays off. eLife 2024; 13:e102187. [PMID: 39311855 PMCID: PMC11419667 DOI: 10.7554/elife.102187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/25/2024] Open
Abstract
Computational principles shed light on why movement is preceded by preparatory activity within the neural networks that control muscles.
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Affiliation(s)
- Mark M Churchland
- Grossman Center for the Statistics of Mind, Columbia University in the City of New York, New York, United States
- Kavli Institute for Brain Science, Columbia University in the City of New York, New York, United States
- Department of Neuroscience, Columbia University in the City of New York, New York, United States
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2
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Grünbaum T, Christensen MS. The functional role of conscious sensation of movement. Neurosci Biobehav Rev 2024; 164:105813. [PMID: 39019245 DOI: 10.1016/j.neubiorev.2024.105813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Revised: 06/25/2024] [Accepted: 07/13/2024] [Indexed: 07/19/2024]
Abstract
This paper proposes a new framework for investigating neural signals sufficient for a conscious sensation of movement and their role in motor control. We focus on signals sufficient for proprioceptive awareness, particularly from muscle spindle activation and from primary motor cortex (M1). Our review of muscle vibration studies reveals that afferent signals alone can induce conscious sensations of movement. Similarly, studies employing peripheral nerve blocks suggest that efferent signals from M1 are sufficient for sensations of movement. On this basis, we show that competing theories of motor control assign different roles to sensation of movement. According to motor command theories, sensation of movement corresponds to an estimation of the current state based on afferent signals, efferent signals, and predictions. In contrast, within active inference architectures, sensations correspond to proprioceptive predictions driven by efferent signals from M1. The focus on sensation of movement provides a way to critically compare and evaluate the two theories. Our analysis offers new insights into the functional roles of movement sensations in motor control and consciousness.
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Affiliation(s)
- Thor Grünbaum
- Department of Psychology, University of Copenhagen, Denmark; CoInAct Research Group, University of Copenhagen, Denmark; Section for Philosophy, University of Copenhagen, Denmark.
| | - Mark Schram Christensen
- Department of Psychology, University of Copenhagen, Denmark; CoInAct Research Group, University of Copenhagen, Denmark
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3
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Egger SW, Keemink SW, Goldman MS, Britten KH. Context-dependence of deterministic and nondeterministic contributions to closed-loop steering control. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.26.605325. [PMID: 39131368 PMCID: PMC11312469 DOI: 10.1101/2024.07.26.605325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/13/2024]
Abstract
In natural circumstances, sensory systems operate in a closed loop with motor output, whereby actions shape subsequent sensory experiences. A prime example of this is the sensorimotor processing required to align one's direction of travel, or heading, with one's goal, a behavior we refer to as steering. In steering, motor outputs work to eliminate errors between the direction of heading and the goal, modifying subsequent errors in the process. The closed-loop nature of the behavior makes it challenging to determine how deterministic and nondeterministic processes contribute to behavior. We overcome this by applying a nonparametric, linear kernel-based analysis to behavioral data of monkeys steering through a virtual environment in two experimental contexts. In a given context, the results were consistent with previous work that described the transformation as a second-order linear system. Classically, the parameters of such second-order models are associated with physical properties of the limb such as viscosity and stiffness that are commonly assumed to be approximately constant. By contrast, we found that the fit kernels differed strongly across tasks in these and other parameters, suggesting context-dependent changes in neural and biomechanical processes. We additionally fit residuals to a simple noise model and found that the form of the noise was highly conserved across both contexts and animals. Strikingly, the fitted noise also closely matched that found previously in a human steering task. Altogether, this work presents a kernel-based analysis that characterizes the context-dependence of deterministic and non-deterministic components of a closed-loop sensorimotor task.
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Affiliation(s)
- Seth W Egger
- Center for Neuroscience, University of California, Davis
| | - Sander W Keemink
- Department of Neurobiology, Physiology and Behavior, University of California, Davis
| | - Mark S Goldman
- Center for Neuroscience, University of California, Davis
- Department of Neurobiology, Physiology and Behavior, University of California, Davis
- Department of Ophthalmology and Vision Science, University of California, Davis
| | - Kenneth H Britten
- Center for Neuroscience, University of California, Davis
- Department of Neurobiology, Physiology and Behavior, University of California, Davis
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Kelley CR, Kauffman JL. Parkinsonian Tremor as Unstable Feedback in a Physiologically Consistent Control Framework. IEEE Trans Neural Syst Rehabil Eng 2024; 32:2665-2675. [PMID: 39018214 DOI: 10.1109/tnsre.2024.3430116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/19/2024]
Abstract
Parkinson's disease (PD) is characterized by decreased dopamine in the basal ganglia that causes excessive tonic inhibition of the thalamus. This excessive inhibition seems to explain inhibitory motor symptoms in PD, but the source of tremor remains unclear. This paper investigates how neural inhibition may change the closed-loop characteristics of the human motor control system to determine how this established pathophysiology could produce tremor. The rate-coding model of neural signals suggests increased inhibition decreases signal amplitude, which could create a mismatch between the closed-loop dynamics and the internal models that overcome proprioceptive feedback delays. This paper aims to identify a candidate model structure with decreased-amplitude-induced tremor in PD that also agrees with previously recorded movements of healthy and cerebellar patients. The optimal feedback control theory of human motor control forms the basis of the model. Key additional elements include gating of undesired movements via the basal ganglia-thalamus-motor cortex circuit and the treatment of the efferent copy of the control input as a measurement in the state estimator. Simulations confirm the model's ability to capture tremor in PD and also demonstrate how disease progression could affect tremor and other motor symptoms, providing insight into the existence of tremor and non-tremor phenotypes. Altogether, the physiological underpinnings of the model structure and the agreement of model predictions with clinical observations provides support for the hypothesis that unstable feedback produces parkinsonian tremor. Consequently, these results also support the associated framework for the neuroanatomy of human motor control.
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Doi Y, Asaka M, Born RT, Yanagihara D, Uchida N. A novel behavioral paradigm using mice to study predictive postural control. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.01.601478. [PMID: 39005260 PMCID: PMC11244922 DOI: 10.1101/2024.07.01.601478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
Postural control circuitry performs the essential function of maintaining balance and body position in response to perturbations that are either self-generated (e.g. reaching to pick up an object) or externally delivered (e.g. being pushed by another person). Human studies have shown that anticipation of predictable postural disturbances can modulate such responses. This indicates that postural control could involve higher-level neural structures associated with predictive functions, rather than being purely reactive. However, the underlying neural circuitry remains largely unknown. To enable studies of predictive postural control circuits, we developed a novel task for mice. In this task, modeled after human studies, a dynamic platform generated reproducible translational perturbations. While mice stood bipedally atop a perch to receive water rewards, they experienced backward translations that were either unpredictable or preceded by an auditory cue. To validate the task, we investigated the effect of the auditory cue on postural responses to perturbations across multiple days in three mice. These preliminary results serve to validate a new postural control model, opening the door to the types of neural recordings and circuit manipulations that are currently possible only in mice.
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Affiliation(s)
- Yurika Doi
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
- Program in Neuroscience, Harvard Medical School, Boston, MA, USA
| | - Meiko Asaka
- Cognition and Behavior Joint Research Laboratory, RIKEN center for Brain Science, Wako, Japan
| | - Richard T. Born
- Program in Neuroscience, Harvard Medical School, Boston, MA, USA
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Dai Yanagihara
- Cognition and Behavior Joint Research Laboratory, RIKEN center for Brain Science, Wako, Japan
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan
| | - Naoshige Uchida
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
- Center for Brain Science, Harvard University, Cambridge, MA, USA
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Harnie J, Al Arab R, Mari S, Yassine S, Eddaoui O, Jéhannin P, Audet J, Lecomte C, Iorio-Morin C, Prilutsky BI, Rybak IA, Frigon A. Forelimb movements contribute to hindlimb cutaneous reflexes during locomotion in cats. J Neurophysiol 2024; 131:997-1013. [PMID: 38691528 PMCID: PMC11381123 DOI: 10.1152/jn.00104.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 04/15/2024] [Accepted: 04/25/2024] [Indexed: 05/03/2024] Open
Abstract
During quadrupedal locomotion, interactions between spinal and supraspinal circuits and somatosensory feedback coordinate forelimb and hindlimb movements. How this is achieved is not clear. To determine whether forelimb movements modulate hindlimb cutaneous reflexes involved in responding to an external perturbation, we stimulated the superficial peroneal nerve in six intact cats during quadrupedal locomotion and during hindlimb-only locomotion (with forelimbs standing on stationary platform) and in two cats with a low spinal transection (T12-T13) during hindlimb-only locomotion. We compared cutaneous reflexes evoked in six ipsilateral and four contralateral hindlimb muscles. Results showed similar occurrence and phase-dependent modulation of short-latency inhibitory and excitatory responses during quadrupedal and hindlimb-only locomotion in intact cats. However, the depth of modulation was reduced in the ipsilateral semitendinosus during hindlimb-only locomotion. Additionally, longer-latency responses occurred less frequently in extensor muscles bilaterally during hindlimb-only locomotion, whereas short-latency inhibitory and longer-latency excitatory responses occurred more frequently in the ipsilateral and contralateral sartorius anterior, respectively. After spinal transection, short-latency inhibitory and excitatory responses were similar to both intact conditions, whereas mid- or longer-latency excitatory responses were reduced or abolished. Our results in intact cats and the comparison with spinal-transected cats suggest that the absence of forelimb movements suppresses inputs from supraspinal structures and/or cervical cord that normally contribute to longer-latency reflex responses in hindlimb extensor muscles.NEW & NOTEWORTHY During quadrupedal locomotion, the coordination of forelimb and hindlimb movements involves central circuits and somatosensory feedback. To demonstrate how forelimb movement affects hindlimb cutaneous reflexes during locomotion, we stimulated the superficial peroneal nerve in intact cats during quadrupedal and hindlimb-only locomotion as well as in spinal-transected cats during hindlimb-only locomotion. We show that forelimb movement influences the modulation of hindlimb cutaneous reflexes, particularly the occurrence of long-latency reflex responses.
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Affiliation(s)
- Jonathan Harnie
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Centre de Recherche du CHUS, Sherbrooke, Quebec, Canada
| | - Rasha Al Arab
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Centre de Recherche du CHUS, Sherbrooke, Quebec, Canada
| | - Stephen Mari
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Centre de Recherche du CHUS, Sherbrooke, Quebec, Canada
| | - Sirine Yassine
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Centre de Recherche du CHUS, Sherbrooke, Quebec, Canada
| | - Oussama Eddaoui
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Centre de Recherche du CHUS, Sherbrooke, Quebec, Canada
| | - Pierre Jéhannin
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Centre de Recherche du CHUS, Sherbrooke, Quebec, Canada
| | - Johannie Audet
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Centre de Recherche du CHUS, Sherbrooke, Quebec, Canada
| | - Charly Lecomte
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Centre de Recherche du CHUS, Sherbrooke, Quebec, Canada
| | - Christian Iorio-Morin
- Division of Neurosurgery, Department of Surgery, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Boris I Prilutsky
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, United States
| | - Ilya A Rybak
- Department of Neurobiology and Anatomy, College of Medicine, Drexel University, Philadelphia, Pennsylvania, United States
| | - Alain Frigon
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Centre de Recherche du CHUS, Sherbrooke, Quebec, Canada
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Sadeghi M, Sharif Razavian R, Bazzi S, Chowdhury RH, Batista AP, Loughlin PJ, Sternad D. Inferring control objectives in a virtual balancing task in humans and monkeys. eLife 2024; 12:RP88514. [PMID: 38738986 PMCID: PMC11090506 DOI: 10.7554/elife.88514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2024] Open
Abstract
Natural behaviors have redundancy, which implies that humans and animals can achieve their goals with different strategies. Given only observations of behavior, is it possible to infer the control objective that the subject is employing? This challenge is particularly acute in animal behavior because we cannot ask or instruct the subject to use a particular strategy. This study presents a three-pronged approach to infer an animal's control objective from behavior. First, both humans and monkeys performed a virtual balancing task for which different control strategies could be utilized. Under matched experimental conditions, corresponding behaviors were observed in humans and monkeys. Second, a generative model was developed that represented two main control objectives to achieve the task goal. Model simulations were used to identify aspects of behavior that could distinguish which control objective was being used. Third, these behavioral signatures allowed us to infer the control objective used by human subjects who had been instructed to use one control objective or the other. Based on this validation, we could then infer objectives from animal subjects. Being able to positively identify a subject's control objective from observed behavior can provide a powerful tool to neurophysiologists as they seek the neural mechanisms of sensorimotor coordination.
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Affiliation(s)
- Mohsen Sadeghi
- Department of Biology, Northeastern UniversityBostonUnited States
| | - Reza Sharif Razavian
- Department of Biology, Northeastern UniversityBostonUnited States
- Department of Electrical and Computer Engineering, Northeastern UniversityBostonUnited States
- Department of Mechanical Engineering, Northern Arizona UniversityFlagstaffUnited States
| | - Salah Bazzi
- Department of Biology, Northeastern UniversityBostonUnited States
- Department of Electrical and Computer Engineering, Northeastern UniversityBostonUnited States
- Institute for Experiential Robotics, Northeastern UniversityBostonUnited States
| | - Raeed H Chowdhury
- Department of Bioengineering, and Center for the Neural Basis of Cognition, University of PittsburghPittsburghUnited States
| | - Aaron P Batista
- Department of Bioengineering, and Center for the Neural Basis of Cognition, University of PittsburghPittsburghUnited States
| | - Patrick J Loughlin
- Department of Bioengineering, and Center for the Neural Basis of Cognition, University of PittsburghPittsburghUnited States
| | - Dagmar Sternad
- Department of Biology, Northeastern UniversityBostonUnited States
- Department of Electrical and Computer Engineering, Northeastern UniversityBostonUnited States
- Institute for Experiential Robotics, Northeastern UniversityBostonUnited States
- Department of Physics, Northeastern UniversityBostonUnited States
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Janeiro Valenciano P, Emiliano Castan V, Henrique Martins Monteiro P, Augusto Teixeira L. Symmetric unipedal balance in quiet stance and dynamic tasks in older individuals. Brain Res 2024; 1830:148850. [PMID: 38460718 DOI: 10.1016/j.brainres.2024.148850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Revised: 02/28/2024] [Accepted: 03/05/2024] [Indexed: 03/11/2024]
Abstract
Previous evidence of increased difference of muscular strength between the dominant and non-dominant legs in older adults suggests the possibility of dissimilar balance control between the legs (between-leg asymmetry) associated with aging. In the current investigation, we evaluated between-leg asymmetries in older adults when performing quiet and dynamic balance tasks. Fifty-two physically active and healthy older adults within the age range of 60 to 80 years were recruited. Participants performed balance tasks in unipedal stance, including quiet standing and cyclic sway (rhythmic oscillation) of the non-supporting leg in the anteroposterior or mediolateral directions, producing foot displacements with amplitudes of 20 cm paced in 1 Hz through a metronome. Body balance was evaluated through trunk accelerometry, by using the sensors embedded into a smartphone fixed at the height of the 10th-12th thoracic spines. Analysis revealed lack of significant differences in balance control between the legs either when comparing the right versus left or the preferred versus non-preferred legs, regardless of whether they were performing quiet stance or dynamic tasks. Further examination of the data showed high between-leg correlation coefficients (rs range: 0.71-0.84) across all tasks. Then, our results indicated symmetric and associated between-leg balance control in the examined older adults.
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Affiliation(s)
- Paola Janeiro Valenciano
- Human Motor Systems Laboratory, School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil.
| | - Victória Emiliano Castan
- Human Motor Systems Laboratory, School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil.
| | | | - Luis Augusto Teixeira
- Human Motor Systems Laboratory, School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil.
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Mari S, Lecomte CG, Merlet AN, Audet J, Yassine S, Eddaoui O, Genois G, Nadeau C, Harnie J, Rybak IA, Prilutsky BI, Frigon A. Changes in intra- and interlimb reflexes from hindlimb cutaneous afferents after staggered thoracic lateral hemisections during locomotion in cats. J Physiol 2024; 602:1987-2017. [PMID: 38593215 PMCID: PMC11068482 DOI: 10.1113/jp286151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 03/04/2024] [Indexed: 04/11/2024] Open
Abstract
When the foot dorsum contacts an obstacle during locomotion, cutaneous afferents signal central circuits to coordinate muscle activity in the four limbs. Spinal cord injury disrupts these interactions, impairing balance and interlimb coordination. We evoked cutaneous reflexes by electrically stimulating left and right superficial peroneal nerves before and after two thoracic lateral hemisections placed on opposite sides of the cord at 9- to 13-week interval in seven adult cats (4 males and 3 females). We recorded reflex responses in ten hindlimb and five forelimb muscles bilaterally. After the first (right T5-T6) and second (left T10-T11) hemisections, coordination of the fore- and hindlimbs was altered and/or became less consistent. After the second hemisection, cats required balance assistance to perform quadrupedal locomotion. Short-latency reflex responses in homonymous and crossed hindlimb muscles largely remained unaffected after staggered hemisections. However, mid- and long-latency homonymous and crossed responses in both hindlimbs occurred less frequently after staggered hemisections. In forelimb muscles, homolateral and diagonal mid- and long-latency response occurrence significantly decreased after the first and second hemisections. In all four limbs, however, when present, short-, mid- and long-latency responses maintained their phase-dependent modulation. We also observed reduced durations of short-latency inhibitory homonymous responses in left hindlimb extensors early after the first hemisection and delayed short-latency responses in the right ipsilesional hindlimb after the first hemisection. Therefore, changes in cutaneous reflex responses correlated with impaired balance/stability and interlimb coordination during locomotion after spinal cord injury. Restoring reflex transmission could be used as a biomarker to facilitate locomotor recovery. KEY POINTS: Cutaneous afferent inputs coordinate muscle activity in the four limbs during locomotion when the foot dorsum contacts an obstacle. Thoracic spinal cord injury disrupts communication between spinal locomotor centres located at cervical and lumbar levels, impairing balance and limb coordination. We investigated cutaneous reflexes during quadrupedal locomotion by electrically stimulating the superficial peroneal nerve bilaterally, before and after staggered lateral thoracic hemisections of the spinal cord in cats. We showed a loss/reduction of mid- and long-latency responses in all four limbs after staggered hemisections, which correlated with altered coordination of the fore- and hindlimbs and impaired balance. Targeting cutaneous reflex pathways projecting to the four limbs could help develop therapeutic approaches aimed at restoring transmission in ascending and descending spinal pathways.
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Affiliation(s)
- Stephen Mari
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Centre de recherche du Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada
| | - Charly G. Lecomte
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Centre de recherche du Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada
| | - Angèle N. Merlet
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Centre de recherche du Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada
| | - Johannie Audet
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Centre de recherche du Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada
| | - Sirine Yassine
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Centre de recherche du Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada
| | - Oussama Eddaoui
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Centre de recherche du Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada
| | - Gabriel Genois
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Centre de recherche du Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada
| | - Charlène Nadeau
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Centre de recherche du Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada
| | - Jonathan Harnie
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Centre de recherche du Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada
| | - Ilya A. Rybak
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, United States
| | - Boris I. Prilutsky
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, United States
| | - Alain Frigon
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Centre de recherche du Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada
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Boebinger S, Payne A, Martino G, Kerr K, Mirdamadi J, McKay JL, Borich M, Ting L. Precise cortical contributions to sensorimotor feedback control during reactive balance. PLoS Comput Biol 2024; 20:e1011562. [PMID: 38630803 PMCID: PMC11057980 DOI: 10.1371/journal.pcbi.1011562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 04/29/2024] [Accepted: 03/25/2024] [Indexed: 04/19/2024] Open
Abstract
The role of the cortex in shaping automatic whole-body motor behaviors such as walking and balance is poorly understood. Gait and balance are typically mediated through subcortical circuits, with the cortex becoming engaged as needed on an individual basis by task difficulty and complexity. However, we lack a mechanistic understanding of how increased cortical contribution to whole-body movements shapes motor output. Here we use reactive balance recovery as a paradigm to identify relationships between hierarchical control mechanisms and their engagement across balance tasks of increasing difficulty in young adults. We hypothesize that parallel sensorimotor feedback loops engaging subcortical and cortical circuits contribute to balance-correcting muscle activity, and that the involvement of cortical circuits increases with balance challenge. We decomposed balance-correcting muscle activity based on hypothesized subcortically- and cortically-mediated feedback components driven by similar sensory information, but with different loop delays. The initial balance-correcting muscle activity was engaged at all levels of balance difficulty. Its onset latency was consistent with subcortical sensorimotor loops observed in the lower limb. An even later, presumed, cortically-mediated burst of muscle activity became additionally engaged as balance task difficulty increased, at latencies consistent with longer transcortical sensorimotor loops. We further demonstrate that evoked cortical activity in central midline areas measured using electroencephalography (EEG) can be explained by a similar sensory transformation as muscle activity but at a delay consistent with its role in a transcortical loop driving later cortical contributions to balance-correcting muscle activity. These results demonstrate that a neuromechanical model of muscle activity can be used to infer cortical contributions to muscle activity without recording brain activity. Our model may provide a useful framework for evaluating changes in cortical contributions to balance that are associated with falls in older adults and in neurological disorders such as Parkinson's disease.
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Affiliation(s)
- Scott Boebinger
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, Georgia, United States of America
| | - Aiden Payne
- Department of Psychology, Florida State University, Tallahassee, Florida, United States of America
| | - Giovanni Martino
- Department of Biomedical Sciences, University of Padova, Padua, Italy
| | - Kennedy Kerr
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, Georgia, United States of America
| | - Jasmine Mirdamadi
- Division of Physical Therapy, Department of Rehabilitation Medicine, Emory University, Atlanta, Georgia, United States of America
| | - J. Lucas McKay
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, Georgia, United States of America
- Departments of Biomedical Informatics and Neurology, Emory University, Atlanta, Georgia, United States of America
| | - Michael Borich
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, Georgia, United States of America
- Division of Physical Therapy, Department of Rehabilitation Medicine, Emory University, Atlanta, Georgia, United States of America
| | - Lena Ting
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, Georgia, United States of America
- Division of Physical Therapy, Department of Rehabilitation Medicine, Emory University, Atlanta, Georgia, United States of America
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11
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Churchland MM, Shenoy KV. Preparatory activity and the expansive null-space. Nat Rev Neurosci 2024; 25:213-236. [PMID: 38443626 DOI: 10.1038/s41583-024-00796-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/26/2024] [Indexed: 03/07/2024]
Abstract
The study of the cortical control of movement experienced a conceptual shift over recent decades, as the basic currency of understanding shifted from single-neuron tuning towards population-level factors and their dynamics. This transition was informed by a maturing understanding of recurrent networks, where mechanism is often characterized in terms of population-level factors. By estimating factors from data, experimenters could test network-inspired hypotheses. Central to such hypotheses are 'output-null' factors that do not directly drive motor outputs yet are essential to the overall computation. In this Review, we highlight how the hypothesis of output-null factors was motivated by the venerable observation that motor-cortex neurons are active during movement preparation, well before movement begins. We discuss how output-null factors then became similarly central to understanding neural activity during movement. We discuss how this conceptual framework provided key analysis tools, making it possible for experimenters to address long-standing questions regarding motor control. We highlight an intriguing trend: as experimental and theoretical discoveries accumulate, the range of computational roles hypothesized to be subserved by output-null factors continues to expand.
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Affiliation(s)
- Mark M Churchland
- Department of Neuroscience, Columbia University, New York, NY, USA.
- Grossman Center for the Statistics of Mind, Columbia University, New York, NY, USA.
- Kavli Institute for Brain Science, Columbia University, New York, NY, USA.
| | - Krishna V Shenoy
- Department of Electrical Engineering, Stanford University, Stanford, CA, USA
- Department of Bioengineering, Stanford University, Stanford, CA, USA
- Department of Neurobiology, Stanford University, Stanford, CA, USA
- Department of Neurosurgery, Stanford University, Stanford, CA, USA
- Wu Tsai Neurosciences Institute, Stanford University, Stanford, CA, USA
- Bio-X Institute, Stanford University, Stanford, CA, USA
- Howard Hughes Medical Institute at Stanford University, Stanford, CA, USA
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Ito T, Bouguerra M, Bourhis M, Perrier P. Tongue reflex for speech posture control. Sci Rep 2024; 14:6386. [PMID: 38493261 PMCID: PMC10944480 DOI: 10.1038/s41598-024-56813-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 03/11/2024] [Indexed: 03/18/2024] Open
Abstract
Although there is no doubt from an empirical viewpoint that reflex mechanisms can contribute to tongue motor control in humans, there is limited neurophysiological evidence to support this idea. Previous results failing to observe any tonic stretch reflex in the tongue had reduced the likelihood of a reflex contribution in tongue motor control. The current study presents experimental evidence of a human tongue reflex in response to a sudden stretch while holding a posture for speech. The latency was relatively long (50 ms), which is possibly mediated through cortical-arc. The activation peak in a speech task was greater than in a non-speech task while background activation levels were similar in both tasks, and the peak amplitude in a speech task was not modulated by the additional task to react voluntarily to the perturbation. Computer simulations with a simplified linear mass-spring-damper model showed that the recorded muscle activation response is suited for the generation of tongue movement responses that were observed in a previous study with the appropriate timing when taking into account a possible physiological delay between reflex muscle activation and the corresponding force. Our results evidenced clearly that reflex mechanisms contribute to tongue posture stabilization for speech production.
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Affiliation(s)
- Takayuki Ito
- Université Grenoble Alpes, CNRS, Grenoble INP (Institute of Engineering Université Grenoble Alpes), GIPSA-lab, 38000, Grenoble, France.
- GIPSA-lab, CNRS, 11 rue des Mathématiques, Grenoble Campus BP46, 38402, Saint Martin d'Hères Cedex, France.
| | - Mohamed Bouguerra
- Université Grenoble Alpes, CNRS, Grenoble INP (Institute of Engineering Université Grenoble Alpes), GIPSA-lab, 38000, Grenoble, France
| | - Morgane Bourhis
- Université Grenoble Alpes, CNRS, Grenoble INP (Institute of Engineering Université Grenoble Alpes), GIPSA-lab, 38000, Grenoble, France
| | - Pascal Perrier
- Université Grenoble Alpes, CNRS, Grenoble INP (Institute of Engineering Université Grenoble Alpes), GIPSA-lab, 38000, Grenoble, France
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13
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Castellote JM, Kofler M, Mayr A. The benefit of knowledge: postural response modulation by foreknowledge of equilibrium perturbation in an upper limb task. Eur J Appl Physiol 2024; 124:975-991. [PMID: 37755580 PMCID: PMC10879248 DOI: 10.1007/s00421-023-05323-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 09/15/2023] [Indexed: 09/28/2023]
Abstract
For whole-body sway patterns, a compound motor response following an external stimulus may comprise reflexes, postural adjustments (anticipatory or compensatory), and voluntary muscular activity. Responses to equilibrium destabilization may depend on both motor set and a subject`s expectation of the disturbing stimulus. To disentangle these influences on lower limb responses, we studied a model in which subjects (n = 14) were suspended in the air, without foot support, and performed a fast unilateral wrist extension (WE) in response to a passive knee flexion (KF) delivered by a robot. To characterize the responses, electromyographic activity of rectus femoris and reactive leg torque was obtained bilaterally in a series of trials, with or without the requirement of WE (motor set), and/or beforehand information about the upcoming velocity of KF (subject`s expectation). Some fast-velocity trials resulted in StartReact responses, which were used to subclassify leg responses. When subjects were uninformed about the upcoming KF, large rectus femoris responses concurred with a postural reaction in conditions without motor task, and with both postural reaction and postural adjustment when WE was required. WE in response to a low-volume acoustic signal elicited no postural adjustments. When subjects were informed about KF velocity and had to perform WE, large rectus femoris responses corresponded to anticipatory postural adjustment rather than postural reaction. In conclusion, when subjects are suspended in the air and have to respond with WE, the prepared motor set includes anticipatory postural adjustments if KF velocity is known, and additional postural reactions if KF velocity is unknown.
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Affiliation(s)
- Juan M Castellote
- Radiology, Rehabilitation and Physiotherapy Department, Faculty of Medicine, Universidad Complutense, Madrid, Spain.
| | - Markus Kofler
- Department of Neurology, Hochzirl Hospital, Zirl, Austria
| | - Andreas Mayr
- Department of Neurology, Hochzirl Hospital, Zirl, Austria
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14
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Reimann H, Bruijn SM. The condition for dynamic stability in humans walking with feedback control. PLoS Comput Biol 2024; 20:e1011861. [PMID: 38498569 PMCID: PMC10997112 DOI: 10.1371/journal.pcbi.1011861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 04/05/2024] [Accepted: 01/24/2024] [Indexed: 03/20/2024] Open
Abstract
The walking human body is mechanically unstable. Loss of stability and falling is more likely in certain groups of people, such as older adults or people with neuromotor impairments, as well as in certain situations, such as when experiencing conflicting or distracting sensory inputs. Stability during walking is often characterized biomechanically, by measures based on body dynamics and the base of support. Neural control of upright stability, on the other hand, does not factor into commonly used stability measures. Here we analyze stability of human walking accounting for both biomechanics and neural control, using a modeling approach. We define a walking system as a combination of biomechanics, using the well known inverted pendulum model, and neural control, using a proportional-derivative controller for foot placement based on the state of the center of mass at midstance. We analyze this system formally and show that for any choice of system parameters there is always one periodic orbit. We then determine when this periodic orbit is stable, i.e. how the neural control gain values have to be chosen for stable walking. Following the formal analysis, we use this model to make predictions about neural control gains and compare these predictions with the literature and existing experimental data. The model predicts that control gains should increase with decreasing cadence. This finding appears in agreement with literature showing stronger effects of visual or vestibular manipulations at different walking speeds.
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Affiliation(s)
- Hendrik Reimann
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware, United States of America
| | - Sjoerd M. Bruijn
- Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
- Institute of Brain and Behavior, Amsterdam, The Netherlands
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15
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Ito S, Gomi H. Modulations of stretch reflex by altering visuomotor contexts. Front Hum Neurosci 2024; 18:1336629. [PMID: 38419960 PMCID: PMC10899434 DOI: 10.3389/fnhum.2024.1336629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Accepted: 02/02/2024] [Indexed: 03/02/2024] Open
Abstract
Various functional modulations of the stretch reflex help to stabilize actions, but the computational mechanism behind its context-dependent tuning remains unclear. While many studies have demonstrated that motor contexts associated with the task goal cause functional modulation of the stretch reflex of upper limbs, it is not well understood how visual contexts independent of the task requirements affect the stretch reflex. To explore this issue, we conducted two experiments testing 20 healthy human participants (age range 20-45, average 31.3 ± 9.0), in which visual contexts were manipulated in a visually guided reaching task. During wrist flexion movements toward a visual target, a mechanical load was applied to the wrist joint to evoke stretch reflex of wrist flexor muscle (flexor carpi radialis). The first experiment (n = 10) examined the effect of altering the visuomotor transformation on the stretch reflex that was evaluated with surface electromyogram. We found that the amplitude of the stretch reflex decreased (p = 0.024) when a rotational transformation of 90° was introduced between the hand movement and the visual cursor, whereas the amplitude did not significantly change (p = 0.26) when the rotational transformation was accompanied by a head rotation so that the configuration of visual feedback was maintained in visual coordinates. The results suggest that the stretch reflex was regulated depending on whether the visuomotor mapping had already been acquired or not. In the second experiment (n = 10), we examined how uncertainty in the visual target or hand cursor affects the stretch reflex by removing these visual stimuli. We found that the reflex amplitude was reduced by the disappearance of the hand cursor (p = 0.039), but was not affected by removal of the visual target (p = 0.27), suggesting that the visual state of the body and target contribute differently to the reflex tuning. These findings support the idea that visual updating of the body state is crucial for regulation of quick motor control driven by proprioceptive signals.
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Affiliation(s)
- Sho Ito
- NTT Communication Science Laboratories, Nippon Telegraph and Telephone Corporation, Atsugi, Japan
- School of Engineering, Tokyo Institute of Technology, Yokohama, Japan
| | - Hiroaki Gomi
- NTT Communication Science Laboratories, Nippon Telegraph and Telephone Corporation, Atsugi, Japan
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16
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Spirina MA, Vlasova TI, Sitdikova AV, Sergachev AV, Chatkin VV, Mezhnov AE. [Neurophysiological substantiation and validity assessment of manual muscle testing in clinical practice. (A literature review)]. VOPROSY KURORTOLOGII, FIZIOTERAPII, I LECHEBNOI FIZICHESKOI KULTURY 2024; 102:70-77. [PMID: 39248589 DOI: 10.17116/kurort202410104170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/10/2024]
Abstract
The relevance of the study of neuromuscular dysfunction's causes and mechanisms is undeniable, considering the large number of nosologies accompanied by malfunction of muscles. Adequate diagnosis and correction of these disorders is impossible without understanding of their pathogenetic mechanisms. Currently, manual muscle testing (MMT) is a widespread technique. MMT is an agile diagnostic tool used by physiatrists, doctors in sports medicine, osteopaths and rehabilitation physicians to assess the functional status of muscles. Unconditionally, this method attracts with its low cost, which will optimize the financial costs of hospital and the healthcare system as a whole. In addition, there is no clear substantiation of the objectivity and validity of the MMT to date. The article considers the issues of neurophysiological principles, classification of methods and approaches, assessment criteria of repeatability and accuracy of MMT. Understanding of the pathophysiological mechanisms of MMT effectiveness will allow to timely correct the therapy and improve the results of treatment and rehabilitation of patients with neuromuscular dysfunction.
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Affiliation(s)
- M A Spirina
- National Research Ogarev Mordovia State University, Saransk, Russia
| | - T I Vlasova
- National Research Ogarev Mordovia State University, Saransk, Russia
| | - A V Sitdikova
- National Research Ogarev Mordovia State University, Saransk, Russia
| | - A V Sergachev
- National Research Ogarev Mordovia State University, Saransk, Russia
| | - V V Chatkin
- National Research Ogarev Mordovia State University, Saransk, Russia
| | - A E Mezhnov
- National Research Ogarev Mordovia State University, Saransk, Russia
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17
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Mari S, Lecomte CG, Merlet AN, Audet J, Yassine S, Eddaoui O, Genois G, Nadeau C, Harnie J, Rybak IA, Prilutsky BI, Frigon A. Changes in intra- and interlimb reflexes from hindlimb cutaneous afferents after staggered thoracic lateral hemisections during locomotion in cats. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.15.571869. [PMID: 38168183 PMCID: PMC10760189 DOI: 10.1101/2023.12.15.571869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
When the foot dorsum contacts an obstacle during locomotion, cutaneous afferents signal central circuits to coordinate muscle activity in the four limbs. Spinal cord injury disrupts these interactions, impairing balance and interlimb coordination. We evoked cutaneous reflexes by electrically stimulating left and right superficial peroneal nerves before and after two thoracic lateral hemisections placed on opposite sides of the cord at 9-13 weeks interval in seven adult cats (4 males and 3 females). We recorded reflex responses in ten hindlimb and five forelimb muscles bilaterally. After the first (right T5-T6) and second (left T10-T11) hemisections, coordination of the fore- and hindlimbs was altered and/or became less consistent. After the second hemisection, cats required balance assistance to perform quadrupedal locomotion. Short-latency reflex responses in homonymous and crossed hindlimb muscles largely remained unaffected after staggered hemisections. However, mid- and long-latency homonymous and crossed responses in both hindlimbs occurred less frequently after staggered hemisections. In forelimb muscles, homolateral and diagonal mid- and long-latency response occurrence significantly decreased after the first and second hemisections. In all four limbs, however, when present, short-, mid- and long-latency responses maintained their phase-dependent modulation. We also observed reduced durations of short-latency inhibitory homonymous responses in left hindlimb extensors early after the first hemisection and delayed short-latency responses in the right ipsilesional hindlimb after the first hemisection. Therefore, changes in cutaneous reflex responses correlated with impaired balance/stability and interlimb coordination during locomotion after spinal cord injury. Restoring reflex transmission could be used as a biomarker to facilitate locomotor recovery.
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Affiliation(s)
- Stephen Mari
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Centre de recherche du Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada
| | - Charly G. Lecomte
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Centre de recherche du Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada
| | - Angèle N. Merlet
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Centre de recherche du Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada
| | - Johannie Audet
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Centre de recherche du Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada
| | - Sirine Yassine
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Centre de recherche du Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada
| | - Oussama Eddaoui
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Centre de recherche du Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada
| | - Gabriel Genois
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Centre de recherche du Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada
| | - Charlène Nadeau
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Centre de recherche du Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada
| | - Jonathan Harnie
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Centre de recherche du Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada
| | - Ilya A. Rybak
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, United States
| | - Boris I. Prilutsky
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, United States
| | - Alain Frigon
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Centre de recherche du Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC, Canada
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18
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Sadeghi M, Razavian RS, Bazzi S, Chowdhury R, Batista A, Loughlin P, Sternad D. Inferring control objectives in a virtual balancing task in humans and monkeys. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.02.539055. [PMID: 37205497 PMCID: PMC10187212 DOI: 10.1101/2023.05.02.539055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Natural behaviors have redundancy, which implies that humans and animals can achieve their goals with different control objectives. Given only observations of behavior, is it possible to infer the control strategy that the subject is employing? This challenge is particularly acute in animal behavior because we cannot ask or instruct the subject to use a particular control strategy. This study presents a threepronged approach to infer an animal's control strategy from behavior. First, both humans and monkeys performed a virtual balancing task for which different control objectives could be utilized. Under matched experimental conditions, corresponding behaviors were observed in humans and monkeys. Second, a generative model was developed that represented two main control strategies to achieve the task goal. Model simulations were used to identify aspects of behavior that could distinguish which control objective was being used. Third, these behavioral signatures allowed us to infer the control objective used by human subjects who had been instructed to use one control objective or the other. Based on this validation, we could then infer strategies from animal subjects. Being able to positively identify a subject's control objective from behavior can provide a powerful tool to neurophysiologists as they seek the neural mechanisms of sensorimotor coordination.
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Affiliation(s)
- Mohsen Sadeghi
- Department of Biology, Northeastern University
- Department of Electrical and Computer Engineering, Northeastern University
| | | | - Salah Bazzi
- Institute for Experiential Robotics, Northeastern University
| | - Raeed Chowdhury
- Department of Bioengineering, and Center for the Neural Basis of Cognition, University of Pittsburgh, PA, USA
| | - Aaron Batista
- Department of Bioengineering, and Center for the Neural Basis of Cognition, University of Pittsburgh, PA, USA
| | - Patrick Loughlin
- Department of Bioengineering, and Center for the Neural Basis of Cognition, University of Pittsburgh, PA, USA
| | - Dagmar Sternad
- Department of Biology, Northeastern University
- Department of Electrical and Computer Engineering, Northeastern University
- Institute for Experiential Robotics, Northeastern University
- Department of Physics, Northeastern University
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19
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Abboud J, Ducas J, Marineau-Bélanger É, Gallina A. Lumbar muscle adaptations to external perturbations are modulated by trunk posture. Eur J Appl Physiol 2023; 123:2191-2202. [PMID: 37247004 DOI: 10.1007/s00421-023-05223-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 05/07/2023] [Indexed: 05/30/2023]
Abstract
PURPOSE To investigate if the recruitment of different regions within the lumbar extensor muscles in response to unexpected perturbations depends on trunk posture. METHODS In a semi-seated posture, healthy adult participants experienced unexpected posterior-anterior trunk perturbations in three different postures: neutral, trunk flexion and left trunk rotation. High-density surface electromyography was used to identify the regional distribution of activation within the lumbar erector spinae muscles. The effect of posture and side (left vs right) on muscle activity and centroid coordinates was investigated at baseline and in response to perturbations. RESULTS Higher muscle activity was observed in trunk flexion compared to neutral and rotation postures at baseline (multiple p < 0.001) and in response to the perturbation (multiple p < 0.01). At baseline, the centroid of the electromyographic amplitude distribution was localized more medially in trunk flexion compared to trunk neutral posture (p = 0.003), while activation was localized more laterally in response to the perturbation (multiple p < 0.05). When the trunk was rotated, the electromyographic amplitude distribution was localized more cranially on the left than the right side, both at baseline (p = 0.001) and in response to the perturbation (p = 0.001). Finally, a more lateral location of the centroid on the left side in rotation compared to neutral posture was observed in response to the perturbation (multiple p < 0.001). CONCLUSIONS Regional differences in the distribution of electromyographic amplitude indicate that different muscle regions were recruited in different trunk postures and in response to perturbations, possibly based on regional mechanical advantage of the erector spinae muscle fibers.
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Affiliation(s)
- Jacques Abboud
- Département des Sciences de l'Activité Physique, Université du Québec à Trois-Rivières, 3351 boul. des Forges, C.P. 500, Trois-Rivières, QC, G8Z 4M3, Canada.
- Groupe de Recherche sur les Affections Neuromusculosquelettiques GRAN, Université du Québec à Trois-Rivières, Trois-Rivières, Canada.
| | - Julien Ducas
- Département des Sciences de l'Activité Physique, Université du Québec à Trois-Rivières, 3351 boul. des Forges, C.P. 500, Trois-Rivières, QC, G8Z 4M3, Canada
- Groupe de Recherche sur les Affections Neuromusculosquelettiques GRAN, Université du Québec à Trois-Rivières, Trois-Rivières, Canada
| | - Émile Marineau-Bélanger
- Département des Sciences de l'Activité Physique, Université du Québec à Trois-Rivières, 3351 boul. des Forges, C.P. 500, Trois-Rivières, QC, G8Z 4M3, Canada
- Groupe de Recherche sur les Affections Neuromusculosquelettiques GRAN, Université du Québec à Trois-Rivières, Trois-Rivières, Canada
| | - Alessio Gallina
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK
- Centre of Precision Rehabilitation for Spinal Pain, School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK
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20
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De Comite A, Lefèvre P, Crevecoeur F. Continuous evaluation of cost-to-go for flexible reaching control and online decisions. PLoS Comput Biol 2023; 19:e1011493. [PMID: 37756355 PMCID: PMC10561875 DOI: 10.1371/journal.pcbi.1011493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 10/09/2023] [Accepted: 09/05/2023] [Indexed: 09/29/2023] Open
Abstract
Humans consider the parameters linked to movement goal during reaching to adjust their control strategy online. Indeed, rapid changes in target structure or disturbances interfering with their initial plan elicit rapid changes in behavior. Here, we hypothesize that these changes could result from the continuous use of a decision variable combining motor and cognitive components. We combine an optimal feedback controller with a real-time evaluation of the expected cost-to-go, which considers target- and movement-related costs, in a common theoretical framework. This model reproduces human behaviors in presence of changes in the target structure occurring during movement and of online decisions to flexibly change target following external perturbations. It also predicts that the time taken to decide to select a novel goal after a perturbation depends on the amplitude of the disturbance and on the rewards of the different options, which is a direct result of the continuous monitoring of the cost-to-go. We show that this result was present in our previously collected dataset. Together our developments point towards a continuous evaluation of the cost-to-go during reaching to update control online and make efficient decisions about movement goal.
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Affiliation(s)
- Antoine De Comite
- Institute of Neuroscience, UCLouvain, Louvain-la-Neuve, Belgium
- Institute of Information and Communication Technologies, Electronics and Applied Mathematics, UCLouvain, Louvain-la-Neuve, Belgium
- McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Philippe Lefèvre
- Institute of Neuroscience, UCLouvain, Louvain-la-Neuve, Belgium
- Institute of Information and Communication Technologies, Electronics and Applied Mathematics, UCLouvain, Louvain-la-Neuve, Belgium
| | - Frédéric Crevecoeur
- Institute of Neuroscience, UCLouvain, Louvain-la-Neuve, Belgium
- Institute of Information and Communication Technologies, Electronics and Applied Mathematics, UCLouvain, Louvain-la-Neuve, Belgium
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21
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Asci F, Falletti M, Zampogna A, Patera M, Hallett M, Rothwell J, Suppa A. Rigidity in Parkinson's disease: evidence from biomechanical and neurophysiological measures. Brain 2023; 146:3705-3718. [PMID: 37018058 PMCID: PMC10681667 DOI: 10.1093/brain/awad114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 03/14/2023] [Accepted: 03/23/2023] [Indexed: 04/06/2023] Open
Abstract
Although rigidity is a cardinal motor sign in patients with Parkinson's disease (PD), the instrumental measurement of this clinical phenomenon is largely lacking, and its pathophysiological underpinning remains still unclear. Further advances in the field would require innovative methodological approaches able to measure parkinsonian rigidity objectively, discriminate the different biomechanical sources of muscle tone (neural or visco-elastic components), and finally clarify the contribution to 'objective rigidity' exerted by neurophysiological responses, which have previously been associated with this clinical sign (i.e. the long-latency stretch-induced reflex). Twenty patients with PD (67.3 ± 6.9 years) and 25 age- and sex-matched controls (66.9 ± 7.4 years) were recruited. Rigidity was measured clinically and through a robotic device. Participants underwent robot-assisted wrist extensions at seven different angular velocities randomly applied, when ON therapy. For each value of angular velocity, several biomechanical (i.e. elastic, viscous and neural components) and neurophysiological measures (i.e. short and long-latency reflex and shortening reaction) were synchronously assessed and correlated with the clinical score of rigidity (i.e. Unified Parkinson's Disease Rating Scale-part III, subitems for the upper limb). The biomechanical investigation allowed us to measure 'objective rigidity' in PD and estimate the neuronal source of this phenomenon. In patients, 'objective rigidity' progressively increased along with the rise of angular velocities during robot-assisted wrist extensions. The neurophysiological examination disclosed increased long-latency reflexes, but not short-latency reflexes nor shortening reaction, in PD compared with control subjects. Long-latency reflexes progressively increased according to angular velocities only in patients with PD. Lastly, specific biomechanical and neurophysiological abnormalities correlated with the clinical score of rigidity. 'Objective rigidity' in PD correlates with velocity-dependent abnormal neuronal activity. The observations overall (i.e. the velocity-dependent feature of biomechanical and neurophysiological measures of objective rigidity) would point to a putative subcortical network responsible for 'objective rigidity' in PD, which requires further investigation.
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Affiliation(s)
- Francesco Asci
- Department of Human Neurosciences, Sapienza University of Rome, 00185 Rome, Italy
- IRCCS Neuromed Institute, 86077 Pozzilli (IS), Italy
| | - Marco Falletti
- Department of Human Neurosciences, Sapienza University of Rome, 00185 Rome, Italy
| | - Alessandro Zampogna
- Department of Human Neurosciences, Sapienza University of Rome, 00185 Rome, Italy
| | - Martina Patera
- Department of Human Neurosciences, Sapienza University of Rome, 00185 Rome, Italy
| | - Mark Hallett
- Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20814, USA
| | - John Rothwell
- UCL Queen Square Institute of Neurology, London WC1N 3BG, UK
| | - Antonio Suppa
- Department of Human Neurosciences, Sapienza University of Rome, 00185 Rome, Italy
- IRCCS Neuromed Institute, 86077 Pozzilli (IS), Italy
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22
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Bittmann FN, Dech S, Schaefer LV. Another Way to Confuse Motor Control: Manual Technique Supposed to Shorten Muscle Spindles Reduces the Muscular Holding Stability in the Sense of Adaptive Force in Male Soccer Players. Brain Sci 2023; 13:1105. [PMID: 37509036 PMCID: PMC10377256 DOI: 10.3390/brainsci13071105] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 07/10/2023] [Accepted: 07/18/2023] [Indexed: 07/30/2023] Open
Abstract
Sensorimotor control can be impaired by slacked muscle spindles. This was shown for reflex responses and, recently, also for muscular stability in the sense of Adaptive Force (AF). The slack in muscle spindles was generated by contracting the lengthened muscle followed by passive shortening. AF was suggested to specifically reflect sensorimotor control since it requires tension-length control in adaptation to an increasing load. This study investigated AF parameters in reaction to another, manually performed slack procedure in a preselected sample (n = 13). The AF of 11 elbow and 12 hip flexors was assessed by an objectified manual muscle test (MMT) using a handheld device. Maximal isometric AF was significantly reduced after manual spindle technique vs. regular MMT. Muscle lengthening started at 64.93 ± 12.46% of maximal voluntary isometric contraction (MVIC). During regular MMT, muscle length could be maintained stable until 92.53 ± 10.12% of MVIC. Hence, muscular stability measured by AF was impaired after spindle manipulation. Force oscillations arose at a significantly lower level for regular vs. spindle. This supports the assumption that they are a prerequisite for stable adaptation. Reduced muscular stability in reaction to slack procedures is considered physiological since sensory information is misled. It is proposed to use slack procedures to test the functionality of the neuromuscular system, which is relevant for clinical practice.
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Affiliation(s)
- Frank N Bittmann
- Regulative Physiology and Prevention, Department Sports and Health Sciences, University of Potsdam, 14476 Potsdam, Germany
| | - Silas Dech
- Regulative Physiology and Prevention, Department Sports and Health Sciences, University of Potsdam, 14476 Potsdam, Germany
- Health Education in Sports, Department Sports and Health Sciences, University of Potsdam, 14476 Potsdam, Germany
| | - Laura V Schaefer
- Regulative Physiology and Prevention, Department Sports and Health Sciences, University of Potsdam, 14476 Potsdam, Germany
- Health Education in Sports, Department Sports and Health Sciences, University of Potsdam, 14476 Potsdam, Germany
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23
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Maurus P, Jackson K, Cashaback JG, Cluff T. The nervous system tunes sensorimotor gains when reaching in variable mechanical environments. iScience 2023; 26:106756. [PMID: 37213228 PMCID: PMC10197011 DOI: 10.1016/j.isci.2023.106756] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 03/10/2023] [Accepted: 04/23/2023] [Indexed: 05/23/2023] Open
Abstract
Humans often move in the presence of mechanical disturbances that can vary in direction and amplitude throughout movement. These disturbances can jeopardize the outcomes of our actions, such as when drinking from a glass of water on a turbulent flight or carrying a cup of coffee while walking on a busy sidewalk. Here, we examine control strategies that allow the nervous system to maintain performance when reaching in the presence of mechanical disturbances that vary randomly throughout movement. Healthy participants altered their control strategies to make movements more robust against disturbances. The change in control was associated with faster reaching movements and increased responses to proprioceptive and visual feedback that were tuned to the variability of the disturbances. Our findings highlight that the nervous system exploits a continuum of control strategies to increase its responsiveness to sensory feedback when reaching in the presence of increasingly variable physical disturbances.
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Affiliation(s)
- Philipp Maurus
- Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
| | - Kuira Jackson
- Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
| | - Joshua G.A. Cashaback
- Department of Biomedical Engineering, University of Delaware, Newark, DE 19716, USA
- Department of Mechanical Engineering, University of Delaware, Newark, DE 19716, USA
- Biomechanics and Movement Science Program, University of Delaware, Newark, DE 19716, USA
| | - Tyler Cluff
- Faculty of Kinesiology, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
- Corresponding author
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24
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Mari S, Lecomte CG, Merlet AN, Audet J, Harnie J, Rybak IA, Prilutsky BI, Frigon A. A sensory signal related to left-right symmetry modulates intra- and interlimb cutaneous reflexes during locomotion in intact cats. Front Syst Neurosci 2023; 17:1199079. [PMID: 37360774 PMCID: PMC10288215 DOI: 10.3389/fnsys.2023.1199079] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Accepted: 05/22/2023] [Indexed: 06/28/2023] Open
Abstract
Introduction During locomotion, cutaneous reflexes play an essential role in rapidly responding to an external perturbation, for example, to prevent a fall when the foot contacts an obstacle. In cats and humans, cutaneous reflexes involve all four limbs and are task- and phase modulated to generate functionally appropriate whole-body responses. Methods To assess task-dependent modulation of cutaneous interlimb reflexes, we electrically stimulated the superficial radial or superficial peroneal nerves in adult cats and recorded muscle activity in the four limbs during tied-belt (equal left-right speeds) and split-belt (different left-right speeds) locomotion. Results We show that the pattern of intra- and interlimb cutaneous reflexes in fore- and hindlimbs muscles and their phase-dependent modulation were conserved during tied-belt and split-belt locomotion. Short-latency cutaneous reflex responses to muscles of the stimulated limb were more likely to be evoked and phase-modulated when compared to muscles in the other limbs. In some muscles, the degree of reflex modulation was significantly reduced during split-belt locomotion compared to tied-belt conditions. Split-belt locomotion increased the step-by-step variability of left-right symmetry, particularly spatially. Discussion These results suggest that sensory signals related to left-right symmetry reduce cutaneous reflex modulation, potentially to avoid destabilizing an unstable pattern.
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Affiliation(s)
- Stephen Mari
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Charly G. Lecomte
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Angèle N. Merlet
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Johannie Audet
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Jonathan Harnie
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Ilya A. Rybak
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, United States
| | - Boris I. Prilutsky
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, United States
| | - Alain Frigon
- Department of Pharmacology-Physiology, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
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25
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Calalo JA, Roth AM, Lokesh R, Sullivan SR, Wong JD, Semrau JA, Cashaback JGA. The sensorimotor system modulates muscular co-contraction relative to visuomotor feedback responses to regulate movement variability. J Neurophysiol 2023; 129:751-766. [PMID: 36883741 PMCID: PMC10069957 DOI: 10.1152/jn.00472.2022] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 02/13/2023] [Accepted: 03/01/2023] [Indexed: 03/09/2023] Open
Abstract
The naturally occurring variability in our movements often poses a significant challenge when attempting to produce precise and accurate actions, which is readily evident when playing a game of darts. Two differing, yet potentially complementary, control strategies that the sensorimotor system may use to regulate movement variability are impedance control and feedback control. Greater muscular co-contraction leads to greater impedance that acts to stabilize the hand, while visuomotor feedback responses can be used to rapidly correct for unexpected deviations when reaching toward a target. Here, we examined the independent roles and potential interplay of impedance control and visuomotor feedback control when regulating movement variability. Participants were instructed to perform a precise reaching task by moving a cursor through a narrow visual channel. We manipulated cursor feedback by visually amplifying movement variability and/or delaying the visual feedback of the cursor. We found that participants decreased movement variability by increasing muscular co-contraction, aligned with an impedance control strategy. Participants displayed visuomotor feedback responses during the task but, unexpectedly, there was no modulation between conditions. However, we did find a relationship between muscular co-contraction and visuomotor feedback responses, suggesting that participants modulated impedance control relative to feedback control. Taken together, our results highlight that the sensorimotor system modulates muscular co-contraction, relative to visuomotor feedback responses, to regulate movement variability and produce accurate actions.NEW & NOTEWORTHY The sensorimotor system has the constant challenge of dealing with the naturally occurring variability in our movements. Here, we investigated the potential roles of muscular co-contraction and visuomotor feedback responses to regulate movement variability. When we visually amplified movements, we found that the sensorimotor system primarily uses muscular co-contraction to regulate movement variability. Interestingly, we found that muscular co-contraction was modulated relative to inherent visuomotor feedback responses, suggesting an interplay between impedance and feedback control.
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Affiliation(s)
- Jan A Calalo
- Department of Biomedical Engineering, University of Delaware, Newark, Delaware, United States
- Department of Mechanical Engineering, University of Delaware, Newark, Delaware, United States
| | - Adam M Roth
- Department of Biomedical Engineering, University of Delaware, Newark, Delaware, United States
- Department of Mechanical Engineering, University of Delaware, Newark, Delaware, United States
| | - Rakshith Lokesh
- Department of Biomedical Engineering, University of Delaware, Newark, Delaware, United States
| | - Seth R Sullivan
- Department of Biomedical Engineering, University of Delaware, Newark, Delaware, United States
| | - Jeremy D Wong
- Department of Kinesiology, University of Calgary, Calgary, Alberta, Canada
- Department of Biomedical Engineering, University of Calgary, Calgary, Alberta, Canada
| | - Jennifer A Semrau
- Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware, United States
- Biomechanics and Movement Science Program, University of Delaware, Newark, Delaware, United States
- Interdisciplinary Neuroscience Graduate Program, University of Delaware, Newark, Delaware, United States
| | - Joshua G A Cashaback
- Department of Biomedical Engineering, University of Delaware, Newark, Delaware, United States
- Department of Mechanical Engineering, University of Delaware, Newark, Delaware, United States
- Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware, United States
- Biomechanics and Movement Science Program, University of Delaware, Newark, Delaware, United States
- Interdisciplinary Neuroscience Graduate Program, University of Delaware, Newark, Delaware, United States
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26
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Bittmann FN, Dech S, Schaefer LV. How to Confuse Motor Control: Passive Muscle Shortening after Contraction in Lengthened Position Reduces the Muscular Holding Stability in the Sense of Adaptive Force. Life (Basel) 2023; 13:life13040911. [PMID: 37109439 PMCID: PMC10143964 DOI: 10.3390/life13040911] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 03/22/2023] [Accepted: 03/28/2023] [Indexed: 04/03/2023] Open
Abstract
Adaptation to external forces relies on a well-functioning proprioceptive system including muscle spindle afferents. Muscle length and tension control in reaction to external forces is most important regarding the Adaptive Force (AF). This study investigated the effect of different procedures, which are assumed to influence the function of muscle spindles, on the AF. Elbow flexors of 12 healthy participants (n = 19 limbs) were assessed by an objectified manual muscle test (MMT) with different procedures: regular MMT, MMT after precontraction (self-estimated 20% MVIC) in lengthened position with passive return to test position (CL), and MMT after CL with a second precontraction in test position (CL-CT). During regular MMTs, muscles maintained their length up to 99.7% ± 1.0% of the maximal AF (AFmax). After CL, muscles started to lengthen at 53.0% ± 22.5% of AFmax. For CL-CT, muscles were again able to maintain the static position up to 98.3% ± 5.5% of AFmax. AFisomax differed highly significantly between CL vs. CL-CT and regular MMT. CL was assumed to generate a slack of muscle spindles, which led to a substantial reduction of the holding capacity. This was immediately erased by a precontraction in the test position. The results substantiate that muscle spindle sensitivity seems to play an important role for neuromuscular functioning and musculoskeletal stability.
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Affiliation(s)
- Frank N. Bittmann
- Regulative Physiology and Prevention, Department Sports and Health Sciences, University of Potsdam, 14476 Potsdam, Germany
| | - Silas Dech
- Regulative Physiology and Prevention, Department Sports and Health Sciences, University of Potsdam, 14476 Potsdam, Germany
- Sports Education, Department Sports and Health Sciences, University of Potsdam, 14476 Potsdam, Germany
| | - Laura V. Schaefer
- Regulative Physiology and Prevention, Department Sports and Health Sciences, University of Potsdam, 14476 Potsdam, Germany
- Sports Education, Department Sports and Health Sciences, University of Potsdam, 14476 Potsdam, Germany
- Correspondence:
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27
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Codol O, Kashefi M, Forgaard CJ, Galea JM, Pruszynski JA, Gribble PL. Sensorimotor feedback loops are selectively sensitive to reward. eLife 2023; 12:81325. [PMID: 36637162 PMCID: PMC9910828 DOI: 10.7554/elife.81325] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 12/29/2022] [Indexed: 01/14/2023] Open
Abstract
Although it is well established that motivational factors such as earning more money for performing well improve motor performance, how the motor system implements this improvement remains unclear. For instance, feedback-based control, which uses sensory feedback from the body to correct for errors in movement, improves with greater reward. But feedback control encompasses many feedback loops with diverse characteristics such as the brain regions involved and their response time. Which specific loops drive these performance improvements with reward is unknown, even though their diversity makes it unlikely that they are contributing uniformly. We systematically tested the effect of reward on the latency (how long for a corrective response to arise?) and gain (how large is the corrective response?) of seven distinct sensorimotor feedback loops in humans. Only the fastest feedback loops were insensitive to reward, and the earliest reward-driven changes were consistently an increase in feedback gains, not a reduction in latency. Rather, a reduction of response latencies only tended to occur in slower feedback loops. These observations were similar across sensory modalities (vision and proprioception). Our results may have implications regarding feedback control performance in athletic coaching. For instance, coaching methodologies that rely on reinforcement or 'reward shaping' may need to specifically target aspects of movement that rely on reward-sensitive feedback responses.
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Affiliation(s)
- Olivier Codol
- Brain and Mind Institute, University of Western OntarioLondonCanada
- Department of Psychology, University of Western OntarioLondonCanada
- School of Psychology, University of BirminghamBirminghamUnited Kingdom
| | - Mehrdad Kashefi
- Brain and Mind Institute, University of Western OntarioLondonCanada
- Department of Psychology, University of Western OntarioLondonCanada
- Department of Physiology & Pharmacology, Schulich School of Medicine & Dentistry, University of Western OntarioOntarioCanada
- Robarts Research Institute, University of Western OntarioLondonCanada
| | - Christopher J Forgaard
- Brain and Mind Institute, University of Western OntarioLondonCanada
- Department of Psychology, University of Western OntarioLondonCanada
| | - Joseph M Galea
- School of Psychology, University of BirminghamBirminghamUnited Kingdom
| | - J Andrew Pruszynski
- Brain and Mind Institute, University of Western OntarioLondonCanada
- Department of Psychology, University of Western OntarioLondonCanada
- Department of Physiology & Pharmacology, Schulich School of Medicine & Dentistry, University of Western OntarioOntarioCanada
- Robarts Research Institute, University of Western OntarioLondonCanada
| | - Paul L Gribble
- Brain and Mind Institute, University of Western OntarioLondonCanada
- Department of Psychology, University of Western OntarioLondonCanada
- Department of Physiology & Pharmacology, Schulich School of Medicine & Dentistry, University of Western OntarioOntarioCanada
- Haskins LaboratoriesNew HavenUnited States
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28
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Schaefer LV, Bittmann FN. Case report: Individualized pulsed electromagnetic field therapy in a Long COVID patient using the Adaptive Force as biomarker. Front Med (Lausanne) 2023; 9:879971. [PMID: 36714125 PMCID: PMC9874300 DOI: 10.3389/fmed.2022.879971] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 12/22/2022] [Indexed: 01/12/2023] Open
Abstract
The increasing prevalence of Long COVID is an imminent public health disaster, and established approaches have not provided adequate diagnostics or treatments. Recently, anesthetic blockade of the stellate ganglion was reported to improve Long COVID symptoms in a small case series, purportedly by "rebooting" the autonomic nervous system. Here, we present a novel diagnostic approach based on the Adaptive Force (AF), and report sustained positive outcome for one severely affected Long COVID patient using individualized pulsed electromagnetic field (PEMF) at the area C7/T1. AF reflects the capacity of the neuromuscular system to adapt adequately to external forces in an isometric holding manner. In case, maximal isometric AF (AFisomax) is exceeded, the muscle merges into eccentric muscle action. Thereby, the force usually increases further until maximal AF (AFmax) is reached. In case adaptation is optimal, AFisomax is ~99-100% of AFmax. This holding capacity (AFisomax) was found to be vulnerable to disruption by unpleasant stimulus and, hence, was regarded as functional parameter. AF was assessed by an objectified manual muscle test using a handheld device. Prior to treatment, AFisomax was considerably lower than AFmax for hip flexors (62 N = ~28% AFmax) and elbow flexors (71 N = ~44% AFmax); i.e., maximal holding capacity was significantly reduced, indicating dysfunctional motor control. We tested PEMF at C7/T1, identified a frequency that improved neuromuscular function, and applied it for ~15 min. Immediately post-treatment, AFisomax increased to ~210 N (~100% AFmax) at hip and 184 N (~100% AFmax) at elbow. Subjective Long COVID symptoms resolved the following day. At 4 weeks post-treatment, maximal holding capacity was still on a similarly high level as for immediately post-treatment (~100% AFmax) and patient was symptom-free. At 6 months the patient's Long COVID symptoms have not returned. This case report suggests (1) AF could be a promising diagnostic for post-infectious illness, (2) AF can be used to test effective treatments for post-infectious illness, and (3) individualized PEMF may resolve post-infectious symptoms.
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Affiliation(s)
- Laura V. Schaefer
- Regulative Physiology and Prevention, Department of Sports and Health Sciences, University Potsdam, Potsdam, Germany
- Practice of Integrative Medicine Bittmann, Potsdam, Germany
| | - Frank N. Bittmann
- Regulative Physiology and Prevention, Department of Sports and Health Sciences, University Potsdam, Potsdam, Germany
- Practice of Integrative Medicine Bittmann, Potsdam, Germany
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29
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Nomberg R, Nisky I. Human Stabilization of Delay-Induced Instability of Haptic Rendering in a Stiffness Discrimination Task. IEEE TRANSACTIONS ON HAPTICS 2023; 16:33-45. [PMID: 36417719 DOI: 10.1109/toh.2022.3221919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Towards developing a coupled stability theory for haptic systems, we study the interaction of operators with time-delayed force feedback. In this work, we analyzed and validated experimentally the stability boundaries of an uncoupled system - without considering the human. We then designed an experiment in which the participants used a haptic device to interact with virtual elastic force fields in a stiffness discrimination task. We compared the performance and kinematics of users in uncoupled-unstable and uncoupled-stable conditions and characterized the stabilizing contribution of the users. We found that the users were able to perform the task regardless of the uncoupled-stability conditions. In addition, in uncoupled-unstable conditions, users maintained movement characteristics that were important for exploratory mediation, such as depth and duration of the movement, whereas other characteristics were not preserved. The results were reproduced in a simulation of the human controller that combined an inverse model and an optimal feedback controller. Adequate performance under the uncoupled-unstable yet coupled-stable conditions supports the potential benefit of designing for coupled stability of haptic systems. This could lead to the use of less conservative controllers than state-of-the-art solutions in haptic and teleoperation systems, and advance the fidelity of haptic feedback.
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30
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Villamar Z, Ludvig D, Perreault EJ. Short-latency stretch reflexes depend on the balance of activity in agonist and antagonist muscles during ballistic elbow movements. J Neurophysiol 2023; 129:7-16. [PMID: 36475940 PMCID: PMC9799151 DOI: 10.1152/jn.00171.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 10/28/2022] [Accepted: 11/27/2022] [Indexed: 12/12/2022] Open
Abstract
The spinal stretch reflex is a fundamental building block of motor function, with a sensitivity that varies continuously during movement and when changing between movement and posture. Many have investigated task-dependent reflex sensitivity, but few have provided simple, quantitative analyses of the relationship between the volitional control and stretch reflex sensitivity throughout tasks that require coordinated activity of several muscles. Here, we develop such an analysis and use it to test the hypothesis that modulation of reflex sensitivity during movement can be explained by the balance of activity within agonist and antagonist muscles better than by activity only in the muscle homonymous with the reflex. Subjects completed hundreds of flexion and extension movements as small, pseudorandom perturbations of elbow angle were applied to obtain estimates of stretch reflex amplitude throughout the movement. A subset of subjects performed a postural control task with muscle activities matched to those during movement. We found that reflex modulation during movement can be described by background activity in antagonist muscles about the elbow much better than by activity only in the muscle homonymous to the reflex (P < 0.001). Agonist muscle activity enhanced reflex sensitivity, whereas antagonist activity suppressed it. Surprisingly, the magnitude of these effects was similar, suggesting a balance of control between agonists and antagonists very different from the dominance of sensitivity to homonymous activity during posture. This balance is due to a large decrease in sensitivity to homonymous muscle activity during movement rather than substantial changes in the influence of antagonistic muscle activity.NEW & NOTEWORTHY This study examined the sensitivity of the stretch reflexes elicited in elbow muscles to the background activity in these same muscles during movement and postural tasks. We found a heightened reciprocal control of reflex sensitivity during movement that was not present during maintenance of posture. These results help explain previous discrepancies in reflex sensitivity measured during movement and posture and provide a simple model for assessing their contributions to muscle activity in both tasks.
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Affiliation(s)
- Zoe Villamar
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois
- Shirley Ryan AbilityLab, Chicago, Illinois
| | - Daniel Ludvig
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois
- Shirley Ryan AbilityLab, Chicago, Illinois
| | - Eric J Perreault
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois
- Shirley Ryan AbilityLab, Chicago, Illinois
- Department of Physical Medicine and Rehabilitation, Northwestern University, Chicago, Illinois
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31
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Gonzalez Polanco P, Mrotek LA, Nielson KA, Beardsley SA, Scheidt RA. When intercepting moving targets, mid-movement error corrections reflect distinct responses to visual and haptic perturbations. Exp Brain Res 2023; 241:231-247. [PMID: 36469052 PMCID: PMC10440829 DOI: 10.1007/s00221-022-06515-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Accepted: 11/20/2022] [Indexed: 12/09/2022]
Abstract
We examined a key aspect of sensorimotor skill: the capability to correct performance errors that arise mid-movement. Participants grasped the handle of a robot that imposed a nominal viscous resistance to hand movement. They watched a target move pseudo-randomly just above the horizontal plane of hand motion and initiated quick interception movements when cued. On some trials, the robot's viscosity or the target's speed changed without warning coincident with the GO cue. We fit a sum-of-Gaussians model to mechanical power measured at the handle to determine the number, magnitude, and relative timing of submovements occurring in each interception attempt. When a single submovement successfully intercepted the target, capture times averaged 410 ms. Sometimes, two or more submovements were required. Initial error corrections typically occurred before feedback could indicate the target had been captured or missed. Error corrections occurred sooner after movement onset in response to mechanical viscosity increases (at 154 ms) than to unprovoked errors on control trials (215 ms). Corrections occurred later (272 ms) in response to viscosity decreases. The latency of corrections for target speed changes did not differ from those in control trials. Remarkably, these early error corrections accommodated the altered testing conditions; speed/viscosity increases elicited more vigorous corrections than in control trials with unprovoked errors; speed/viscosity decreases elicited less vigorous corrections. These results suggest that the brain monitors and predicts the outcome of evolving movements, rapidly infers causes of mid-movement errors, and plans and executes corrections-all within 300 ms of movement onset.
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Affiliation(s)
- Pablo Gonzalez Polanco
- Biomedical Engineering, Marquette University and Medical College of Wisconsin, Olin Engineering Center Rm 206, 1515 W. Wisconsin Ave, Milwaukee, WI, 53233, USA
| | - Leigh A Mrotek
- Biomedical Engineering, Marquette University and Medical College of Wisconsin, Olin Engineering Center Rm 206, 1515 W. Wisconsin Ave, Milwaukee, WI, 53233, USA
| | - Kristy A Nielson
- Psychology, Marquette University and Neurology, Medical College of Wisconsin, Milwaukee, WI, 53233, USA
| | - Scott A Beardsley
- Biomedical Engineering, Marquette University and Medical College of Wisconsin, Olin Engineering Center Rm 206, 1515 W. Wisconsin Ave, Milwaukee, WI, 53233, USA
| | - Robert A Scheidt
- Biomedical Engineering, Marquette University and Medical College of Wisconsin, Olin Engineering Center Rm 206, 1515 W. Wisconsin Ave, Milwaukee, WI, 53233, USA.
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32
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How can caching explain automaticity? Psychon Bull Rev 2022; 30:407-420. [PMID: 36224462 DOI: 10.3758/s13423-022-02191-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/15/2022] [Indexed: 11/08/2022]
Abstract
Automaticity is still ill-understood, and its relation to habit formation and skill acquisition is highly debated. Recently, the principle of caching has been advanced as a potentially promising avenue for studying automaticity. It is roughly understood as a means of storing direct input-output associations in a manner that supports instant lookup. We raise various concerns that should be addressed before the theoretical progress afforded by this principle can be evaluated. Is caching merely a metaphor for computer caching or is it a computational model that can be used to derive testable predictions? How do the short-term and long-term effects of automaticity relate to the distinction between working memory and long-term memory? Does caching apply to stimulus-response associations - as already suggested by Logan's instance theory - or to algorithms, too? How much practice is required for caching and how does caching depend on the task's type? What is the relation between control processes and caching as these pertain to the possible suppression of automatic processes? Dealing with these questions will arguably also advance our understanding of automaticity.
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33
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Cherif A, Zenzeri J, Loram I. What is the contribution of voluntary and reflex processes to sensorimotor control of balance? Front Bioeng Biotechnol 2022; 10:973716. [PMID: 36246368 PMCID: PMC9557221 DOI: 10.3389/fbioe.2022.973716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 08/18/2022] [Indexed: 11/24/2022] Open
Abstract
The contribution to balance of spinal and transcortical processes including the long-latency reflex is well known. The control of balance has been modelled previously as a continuous, state feedback controller representing, long-latency reflexes. However, the contribution of slower, variable delay processes has not been quantified. Compared with fixed delay processes (spinal, transcortical), we hypothesize that variable delay processes provide the largest contribution to balance and are sensitive to historical context as well as current states. Twenty-two healthy participants used a myoelectric control signal from their leg muscles to maintain balance of their own body while strapped to an actuated, inverted pendulum. We study the myoelectric control signal (u) in relation to the independent disturbance (d) comprising paired, discrete perturbations of varying inter-stimulus-interval (ISI). We fit the closed loop response, u from d, using one linear and two non-linear non-parametric (many parameter) models. Model M1 (ARX) is a generalized, high-order linear-time-invariant (LTI) process with fixed delay. Model M1 is equivalent to any parametric, closed-loop, continuous, linear-time-invariant (LTI), state feedback model. Model M2, a single non-linear process (fixed delay, time-varying amplitude), adds an optimized response amplitude to each stimulus. Model M3, two non-linear processes (one fixed delay, one variable delay, each of time-varying amplitude), add a second process of optimized delay and optimized response amplitude to each stimulus. At short ISI, the myoelectric control signals deviated systematically both from the fixed delay LTI process (M1), and also from the fixed delay, time-varying amplitude process (M2) and not from the two-process model (M3). Analysis of M3 (all fixed delay and variable delay response amplitudes) showed the variable (compared with fixed) delay process 1) made the largest contribution to the response, 2) exhibited refractoriness (increased delay related to short ISI) and 3) was sensitive to stimulus history (stimulus direction 2 relative to stimulus 1). For this whole-body balance task and for these impulsive stimuli, non-linear processes at variable delay are central to control of balance. Compared with fixed delay processes (spinal, transcortical), variable delay processes provided the largest contribution to balance and were sensitive to historical context as well as current states.
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Affiliation(s)
- Amel Cherif
- Department of Robotics, Brain and Cognitive Sciences, Istituto Italiano di Tecnologia, Genoa, Italy
- *Correspondence: Amel Cherif, ; Ian Loram,
| | - Jacopo Zenzeri
- Department of Robotics, Brain and Cognitive Sciences, Istituto Italiano di Tecnologia, Genoa, Italy
| | - Ian Loram
- Cognitive Motor Function Research Group, Research Centre for Musculoskeletal Science & Sports Medicine, Dept of Life Sciences, Faculty of Science and Engineering, Manchester Metropolitan University, Manchester, United Kingdom
- *Correspondence: Amel Cherif, ; Ian Loram,
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34
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Dimitriou M. Human muscle spindles are wired to function as controllable signal-processing devices. eLife 2022; 11:e78091. [PMID: 35829705 PMCID: PMC9278952 DOI: 10.7554/elife.78091] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 06/29/2022] [Indexed: 12/26/2022] Open
Abstract
Muscle spindles are encapsulated sensory organs found in most of our muscles. Prevalent models of sensorimotor control assume the role of spindles is to reliably encode limb posture and movement. Here, I argue that the traditional view of spindles is outdated. Spindle organs can be tuned by spinal γ motor neurons that receive top-down and peripheral input, including from cutaneous afferents. A new model is presented, viewing γ motor activity as an intermediate coordinate transformation that allows multimodal information to converge on spindles, creating flexible coordinate representations at the level of the peripheral nervous system. That is, I propose that spindles play a unique overarching role in the nervous system: that of a peripheral signal-processing device that flexibly facilitates sensorimotor performance, according to task characteristics. This role is compatible with previous findings and supported by recent studies with naturalistically active humans. Such studies have so far shown that spindle tuning enables the independent preparatory control of reflex muscle stiffness, the selective extraction of information during implicit motor adaptation, and for segmental stretch reflexes to operate in joint space. Incorporation of advanced signal-processing at the periphery may well prove a critical step in the evolution of sensorimotor control theories.
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Affiliation(s)
- Michael Dimitriou
- Physiology Section, Department of Integrative Medical Biology, Umeå UniversityUmeåSweden
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35
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Corcos DM, Myklebust BM, Latash ML. The legacy of Gerald L. Gottlieb in human movement neuroscience. J Neurophysiol 2022; 128:148-159. [PMID: 35675443 DOI: 10.1152/jn.00141.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In this paper, we review the legacy of Gerald (Gerry) Gottlieb in various fields related to the neural control of human movement. His studies on the myotatic (stretch) reflex and postmyotatic responses to ankle joint perturbations paved the way for current explorations of long-loop reflexes and their role in the control of movement. The dual-strategy hypothesis introduced order into a large body of literature on the triphasic muscle activation patterns seen over a variety of voluntary movements in healthy persons. The dual-strategy hypothesis continues to be important for understanding the performance of subjects with disordered motor control. The principle of linear synergy (covariance of joint torques) was an attempt to solve one of the notorious problems of motor redundancy, which remains an important topic in the field. Gerry's attitude toward the equilibrium-point hypothesis varied between rejection and using it to explore patterns of hypothetical control variables and movement variability. The discovery of reciprocal excitation in healthy neonates fostered other studies of changes in spinal cord physiology as motor skills develop. In addition, studies of people with spasticity and the effects of treatment with intrathecal baclofen were crucial in demonstrating the possibility of unmasking voluntary movements after suppression of the hyperreflexia of spasticity. Gerry Gottlieb contributed a significant body of knowledge that formed a solid foundation from which to study a variety of neurological diseases and their treatments, and a more comprehensive and parsimonious foundation to describe the neural control of human movement.
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Affiliation(s)
- Daniel M Corcos
- Department of Physical Therapy and Human Movement Sciences, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Barbara M Myklebust
- Retired from the Office of Surveillance and Biometrics and the Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, US Food and Drug Administration, Silver Spring, Maryland
| | - Mark L Latash
- Department of Kinesiology, The Pennsylvania State University, University Park, Pennsylvania
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Česonis J, Franklin DW. Contextual cues are not unique for motor learning: Task-dependant switching of feedback controllers. PLoS Comput Biol 2022; 18:e1010192. [PMID: 35679316 PMCID: PMC9217135 DOI: 10.1371/journal.pcbi.1010192] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 06/22/2022] [Accepted: 05/09/2022] [Indexed: 11/18/2022] Open
Abstract
The separation of distinct motor memories by contextual cues is a well known and well studied phenomenon of feedforward human motor control. However, there is no clear evidence of such context-induced separation in feedback control. Here we test both experimentally and computationally if context-dependent switching of feedback controllers is possible in the human motor system. Specifically, we probe visuomotor feedback responses of our human participants in two different tasks—stop and hit—and under two different schedules. The first, blocked schedule, is used to measure the behaviour of stop and hit controllers in isolation, showing that it can only be described by two independent controllers with two different sets of control gains. The second, mixed schedule, is then used to compare how such behaviour evolves when participants regularly switch from one task to the other. Our results support our hypothesis that there is contextual switching of feedback controllers, further extending the accumulating evidence of shared features between feedforward and feedback control. Extensive evidence has demonstrated that humans can learn distinct motor memories (i.e. independent feedforward controllers) using contextual cues. However, there is little evidence that such contextual cues produce similar separation of feedback controllers. As accumulating evidence highlights the connection between feedforward and feedback control, we propose that context may be used to separate feedback controllers as well. It has not been trivial to test experimentally whether a change in context also modulates the feedback control, as the controller output is affected by other non-contextual factors such as movement kinematics, time-to-target or the properties of the perturbation used to probe the control. Here we present a computational approach based on normative modelling where we separate the effects of the context from other non-contextual effects on the visuomotor feedback system. We then show experimentally that task context independently modulates the feedback control in a particular manner that can be reliably predicted using optimal feedback control.
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Affiliation(s)
- Justinas Česonis
- Neuromuscular Diagnostics, Department of Sport and Health Sciences, Technical University of Munich, Munich, Germany
| | - David W. Franklin
- Neuromuscular Diagnostics, Department of Sport and Health Sciences, Technical University of Munich, Munich, Germany
- Munich Institute of Robotics and Machine Intelligence (MIRMI), Technical University of Munich, Munich, Germany
- Munich Data Science Institute (MDSI), Technical University of Munich, Munich, Germany
- * E-mail:
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Saxena S, Russo AA, Cunningham J, Churchland MM. Motor cortex activity across movement speeds is predicted by network-level strategies for generating muscle activity. eLife 2022; 11:e67620. [PMID: 35621264 PMCID: PMC9197394 DOI: 10.7554/elife.67620] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 05/26/2022] [Indexed: 12/02/2022] Open
Abstract
Learned movements can be skillfully performed at different paces. What neural strategies produce this flexibility? Can they be predicted and understood by network modeling? We trained monkeys to perform a cycling task at different speeds, and trained artificial recurrent networks to generate the empirical muscle-activity patterns. Network solutions reflected the principle that smooth well-behaved dynamics require low trajectory tangling. Network solutions had a consistent form, which yielded quantitative and qualitative predictions. To evaluate predictions, we analyzed motor cortex activity recorded during the same task. Responses supported the hypothesis that the dominant neural signals reflect not muscle activity, but network-level strategies for generating muscle activity. Single-neuron responses were better accounted for by network activity than by muscle activity. Similarly, neural population trajectories shared their organization not with muscle trajectories, but with network solutions. Thus, cortical activity could be understood based on the need to generate muscle activity via dynamics that allow smooth, robust control over movement speed.
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Affiliation(s)
- Shreya Saxena
- Department of Electrical and Computer Engineering, University of FloridaGainesvilleUnited States
- Zuckerman Mind Brain Behavior Institute, Columbia UniversityNew YorkUnited States
- Grossman Center for the Statistics of Mind, Columbia UniversityNew YorkUnited States
- Center for Theoretical Neuroscience, Columbia UniversityNew YorkUnited States
- Department of Statistics, Columbia UniversityNew YorkUnited States
| | - Abigail A Russo
- Zuckerman Mind Brain Behavior Institute, Columbia UniversityNew YorkUnited States
- Department of Neuroscience, Columbia UniversityNew YorkUnited States
| | - John Cunningham
- Zuckerman Mind Brain Behavior Institute, Columbia UniversityNew YorkUnited States
- Grossman Center for the Statistics of Mind, Columbia UniversityNew YorkUnited States
- Center for Theoretical Neuroscience, Columbia UniversityNew YorkUnited States
- Department of Statistics, Columbia UniversityNew YorkUnited States
| | - Mark M Churchland
- Zuckerman Mind Brain Behavior Institute, Columbia UniversityNew YorkUnited States
- Grossman Center for the Statistics of Mind, Columbia UniversityNew YorkUnited States
- Department of Neuroscience, Columbia UniversityNew YorkUnited States
- Kavli Institute for Brain Science, Columbia UniversityNew YorkUnited States
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38
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Mannella K, Forman GN, Mugnosso M, Zenzeri J, Holmes MWR. The effects of isometric hand grip force on wrist kinematics and forearm muscle activity during radial and ulnar wrist joint perturbations. PeerJ 2022; 10:e13495. [PMID: 35646483 PMCID: PMC9138088 DOI: 10.7717/peerj.13495] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 05/04/2022] [Indexed: 01/17/2023] Open
Abstract
The purpose of this work was to investigate forearm muscle activity and wrist angular displacement during radial and ulnar wrist perturbations across various isometric hand grip demands. Surface electromyography (EMG) was recorded from eight muscles of the upper extremity. A robotic device delivered perturbations to the hand in the radial and ulnar directions across four pre-perturbation grip magnitudes. Angular displacement and time to peak displacement following perturbations were evaluated. Muscle activity was evaluated pre- and post-perturbation. Results showed an inverse relationship between grip force and angular displacement (p ≤ 0.001). Time to peak displacement decreased as grip force increased (p ≤ 0.001). There was an increase in muscle activity with higher grip forces across all muscles both pre-and post-perturbation (p ≤ 0.001) and a greater average muscle activity in ulnar as compared to radial deviation (p = 0.02). This work contributes to the wrist joint stiffness literature by relating wrist angular displacement to grip demands during novel radial/ulnar perturbations and provides insight into neuromuscular control strategies.
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Affiliation(s)
- Kailynn Mannella
- Department of Kinesiology, Brock University, St. Catharines, Canada
| | | | - Maddalena Mugnosso
- Robotics, Brain and Cognitive Sciences, Istituto Italiano di Tecnologia, Genoa, Italy
| | - Jacopo Zenzeri
- Robotics, Brain and Cognitive Sciences, Istituto Italiano di Tecnologia, Genoa, Italy
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Poirier G, Papaxanthis C, Mourey F, Lebigre M, Gaveau J. Muscle effort is best minimized by the right-dominant arm in the gravity field. J Neurophysiol 2022; 127:1117-1126. [PMID: 35353617 DOI: 10.1152/jn.00324.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The central nervous system (CNS) develops motor strategies that minimize various hidden criteria, such as end-point variance or effort. A large body of literature suggests that the dominant arm is specialized for such open-loop optimization-like processes, whilst the non-dominant arm is specialized for closed-loop postural control. Building on recent results suggesting that the brain plans arm movements that take advantage of gravity effects to minimize muscle effort, the present study tests the hypothesized superiority of the dominant arm motor system for effort minimization. Thirty participants (22.5 ± 2.1 years old; all right-handed) performed vertical arm movements between two targets (40° amplitude), in two directions (upwards and downwards) with their two arms (dominant and non-dominant). We recorded the arm kinematics and electromyographic activities of the anterior and posterior deltoid to compare two motor signatures of the gravity-related optimization process; i.e., directional asymmetries and negative epochs on phasic muscular activity. We found that these motor signatures were still present during movements performed with the non-dominant arm, indicating that the effort-minimization process also occurs for the non-dominant motor system. However, these markers were reduced compared with movements performed with the dominant arm. This difference was especially prominent during downward movements, where the optimization of gravity effects occurs early in the movement. Assuming that the dominant arm is optimal to minimize muscle effort, as demonstrated by previous studies, the present results support the hypothesized superiority of the dominant arm motor system for effort-minimization.
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Affiliation(s)
- Gabriel Poirier
- INSERM U1093-CAPS, Université Bourgogne Franche-Comté, UFR des Sciences du Sport, Dijon, France
| | - Charalambos Papaxanthis
- INSERM U1093-CAPS, Université Bourgogne Franche-Comté, UFR des Sciences du Sport, Dijon, France
| | - France Mourey
- INSERM U1093-CAPS, Université Bourgogne Franche-Comté, UFR des Sciences du Sport, Dijon, France
| | - Melanie Lebigre
- INSERM U1093-CAPS, Université Bourgogne Franche-Comté, UFR des Sciences du Sport, Dijon, France
| | - Jérémie Gaveau
- INSERM U1093-CAPS, Université Bourgogne Franche-Comté, UFR des Sciences du Sport, Dijon, France
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40
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Reward-Dependent Selection of Feedback Gains Impacts Rapid Motor Decisions. eNeuro 2022; 9:ENEURO.0439-21.2022. [PMID: 35277452 PMCID: PMC8970337 DOI: 10.1523/eneuro.0439-21.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 02/22/2022] [Accepted: 03/04/2022] [Indexed: 11/21/2022] Open
Abstract
Target reward influences motor planning strategies through modulation of movement vigor. Considering current theories of sensorimotor control suggesting that movement planning consists in selecting a goal-directed control strategy, we sought to investigate the influence of reward on feedback control. Here, we explored this question in three human reaching experiments. First, we altered the explicit reward associated with the goal target and found an overall increase in feedback gains for higher target rewards, highlighted by larger velocities, feedback responses to external loads, and background muscle activity. Then, we investigated whether the differences in target rewards across multiple goals impacted rapid motor decisions during movement. We observed idiosyncratic switching strategies dependent on both target rewards and, surprisingly, the feedback gains at perturbation onset: the more vigorous movements were less likely to switch to a new goal following perturbations. To gain further insight into a causal influence of the feedback gains on rapid motor decisions, we demonstrated that biasing the baseline activity and reflex gains by means of a background load evoked a larger proportion of target switches in the direction opposite to the background load associated with lower muscle activity. Together, our results demonstrate an impact of target reward on feedback control and highlight the competition between movement vigor and flexibility.
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Jayasinghe SAL, Scheidt RA, Sainburg RL. Neural Control of Stopping and Stabilizing the Arm. Front Integr Neurosci 2022; 16:835852. [PMID: 35264934 PMCID: PMC8899537 DOI: 10.3389/fnint.2022.835852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 01/17/2022] [Indexed: 11/27/2022] Open
Abstract
Stopping is a crucial yet under-studied action for planning and producing meaningful and efficient movements. In this review, we discuss classical human psychophysics studies as well as those using engineered systems that aim to develop models of motor control of the upper limb. We present evidence for a hybrid model of motor control, which has an evolutionary advantage due to division of labor between cerebral hemispheres. Stopping is a fundamental aspect of movement that deserves more attention in research than it currently receives. Such research may provide a basis for understanding arm stabilization deficits that can occur following central nervous system (CNS) damage.
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Affiliation(s)
- Shanie A. L. Jayasinghe
- Department of Neurology, Pennsylvania State University College of Medicine, Hershey, PA, United States
| | - Robert A. Scheidt
- Department of Biomedical Engineering, Marquette University and Medical College of Wisconsin, Milwaukee, WI, United States
| | - Robert L. Sainburg
- Department of Neurology, Pennsylvania State University College of Medicine, Hershey, PA, United States
- Department of Kinesiology, Pennsylvania State University, State College, PA, United States
- Huck Institutes of the Life Sciences, Pennsylvania State University, State College, PA, United States
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42
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York G, Osborne H, Sriya P, Astill S, de Kamps M, Chakrabarty S. The effect of limb position on a static knee extension task can be explained with a simple spinal cord circuit model. J Neurophysiol 2022; 127:173-187. [PMID: 34879209 PMCID: PMC8802899 DOI: 10.1152/jn.00208.2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The influence of proprioceptive feedback on muscle activity during isometric tasks is the subject of conflicting studies. We performed an isometric knee extension task experiment based on two common clinical tests for mobility and flexibility. The task was carried out at four preset angles of the knee, and we recorded from five muscles for two different hip positions. We applied muscle synergy analysis using nonnegative matrix factorization on surface electromyograph recordings to identify patterns in the data that changed with internal knee angle, suggesting a link between proprioception and muscle activity. We hypothesized that such patterns arise from the way proprioceptive and cortical signals are integrated in neural circuits of the spinal cord. Using the MIIND neural simulation platform, we developed a computational model based on current understanding of spinal circuits with an adjustable afferent input. The model produces the same synergy trends as observed in the data, driven by changes in the afferent input. To match the activation patterns from each knee angle and position of the experiment, the model predicts the need for three distinct inputs: two to control a nonlinear bias toward the extensors and against the flexors, and a further input to control additional inhibition of rectus femoris. The results show that proprioception may be involved in modulating muscle synergies encoded in cortical or spinal neural circuits.NEW & NOTEWORTHY The role of sensory feedback in motor control when limbs are held in a fixed position is disputed. We performed a novel experiment involving fixed position tasks based on two common clinical tests. We identified patterns of muscle activity during the tasks that changed with different leg positions and then inferred how sensory feedback might influence the observations. We developed a computational model that required three distinct inputs to reproduce the activity patterns observed experimentally. The model provides a neural explanation for how the activity patterns can be changed by sensory feedback.
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Affiliation(s)
- Gareth York
- 1School of Biomedical Sciences Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Hugh Osborne
- 2Institute for Artificial Intelligence and Biological Computation School of Computing, University of Leeds, Leeds, United Kingdom
| | - Piyanee Sriya
- 1School of Biomedical Sciences Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Sarah Astill
- 1School of Biomedical Sciences Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Marc de Kamps
- 2Institute for Artificial Intelligence and Biological Computation School of Computing, University of Leeds, Leeds, United Kingdom
| | - Samit Chakrabarty
- 2Institute for Artificial Intelligence and Biological Computation School of Computing, University of Leeds, Leeds, United Kingdom
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Anastasopoulos D, Anastasopoulos L, Mergner T. Voluntary suppression of neck reflexes during passive head-on-trunk rotations - reflex gain control vs. proprioceptive feedback. J Neurophysiol 2021; 127:161-172. [PMID: 34907798 PMCID: PMC8858664 DOI: 10.1152/jn.00297.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Normal subjects can completely eliminate resistance upon imposed head-on-trunk rotations when they are asked to relax. It is not, however, clear how neck reflexes to stretch can be voluntarily suppressed. Reflexive responses might be modified by adjusting the gain of the reflex loop through descending control. Theoretically, necessary corrections upon interfering disturbances during coordinated motor performance requiring the interplay of relaxation/activation may be missing if muscle relaxation is taking place exclusively by this mechanism. It has been alternatively proposed that sensory information from the periphery may be allowed to “neutralize” neck reflexes if it is fed back with opposite sign to the structures driving the reflexes. Six healthy subjects were asked to relax while subjected to head-on-trunk rotations generated by a head motor. After any initial resistance had completely subsided, the head was unexpectedly exposed to “ramp-and-hold” perturbations of up to 2° amplitude and 0.7 s duration. Resistance to stretch consistently reappeared thereupon, suggesting that stretch reflex gain had not been set to zero during the previously achieved complete relaxation. Resistance to perturbations under these circumstances was compared with the forces generated when the same ramp-and-hold displacements were delivered unpredictably to the head held stationary. A quantitative model of neck proprioceptive reflexes suppression has been thus constructed. Gain scheduling or “motor set” cannot sufficiently account for the voluntary reflex suppression during slow passive head rotations. Instead, we propose as underlying mechanism, the “neutralization” of the controlling servo by means of continuous feedback tracking displacement and force signals from the periphery. NEW & NOTEWORTHY Head stabilizing neck reflexes can be voluntarily suppressed or activated depending on the task at hand. By applying brief perturbations unexpectedly, both during passive head-on-trunk movements and at rest, we investigated the mechanism of voluntary suppression of resistance to stretch. A physiologically plausible, neuromechanical model of voluntary/reflexive interactions was constructed favoring feedback over reflex gain adjustments. Accordingly, muscle relaxation during imposed head movements is based on sensory feedback similarly to muscle contractions during purposeful movements.
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Affiliation(s)
- Dimitri Anastasopoulos
- Department of Neurorehabilitation, Zurzachcare, Bad Zurzach, Switzerland.,Department of Physiology, University of Athens, Athens, Greece
| | | | - Thomas Mergner
- Department of Neurology, University of Freiburg, Germany
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Kasuga S, Crevecoeur F, Cross KP, Balalaie P, Scott SH. Integration of proprioceptive and visual feedback during online control of reaching. J Neurophysiol 2021; 127:354-372. [PMID: 34907796 PMCID: PMC8794063 DOI: 10.1152/jn.00639.2020] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Visual and proprioceptive feedback both contribute to perceptual decisions, but it remains unknown how these feedback signals are integrated together or consider factors such as delays and variance during online control. We investigated this question by having participants reach to a target with randomly applied mechanical and/or visual disturbances. We observed that the presence of visual feedback during a mechanical disturbance did not increase the size of the muscle response significantly but did decrease variance, consistent with a dynamic Bayesian integration model. In a control experiment, we verified that vision had a potent influence when mechanical and visual disturbances were both present but opposite in sign. These results highlight a complex process for multisensory integration, where visual feedback has a relatively modest influence when the limb is mechanically disturbed, but a substantial influence when visual feedback becomes misaligned with the limb. NEW & NOTEWORTHY Visual feedback is more accurate, but proprioceptive feedback is faster. How should you integrate these sources of feedback to guide limb movement? As predicted by dynamic Bayesian models, the size of the muscle response to a mechanical disturbance was essentially the same whether visual feedback was present or not. Only under artificial conditions, such as when shifting the position of a cursor representing hand position, can one observe a muscle response from visual feedback.
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Affiliation(s)
- Shoko Kasuga
- Centre for Neuroscience Studies, Queen's University, Kingston, Ontario, Canada
| | - Frédéric Crevecoeur
- Institute of Communication Technologies, Electronics and Applied Mathematics, Université Catholique de Louvain, Louvain-la-Neuve, Belgium.,Institute of Neuroscience, Université Catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Kevin Patrick Cross
- Centre for Neuroscience Studies, Queen's University, Kingston, Ontario, Canada
| | - Parsa Balalaie
- Centre for Neuroscience Studies, Queen's University, Kingston, Ontario, Canada
| | - Stephen H Scott
- Centre for Neuroscience Studies, Queen's University, Kingston, Ontario, Canada.,Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada.,Department of Medicine, Queen's University, Kingston, Ontario, Canada
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Penedo T, Vuillerme N, Balistieri Santinelli F, Felipe Moretto G, de Carvalho Costa E, Pilon J, Augusto Kalva-Filho C, Barbieri FA. Ankle muscle fatigability impairs body sway for more than 24 h. J Biomech 2021; 133:110890. [PMID: 35121381 DOI: 10.1016/j.jbiomech.2021.110890] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 11/24/2021] [Accepted: 11/25/2021] [Indexed: 01/12/2023]
Abstract
This study aimed to investigate if the impairing in postural control, induced by ankle fatiguing exercise, remains after 24/48 h in young adults. Center of Pressure (CoP) was assessed in 16 participants (23 ± 3 years old) before, immediately after an ankle fatigability induction protocol (FI) and after 24 or 48 h of recovery using two 60-s trials with eyes open (EO) and closed (EC). The FI consisted of performing the ankle plantar flexion and dorsiflexion movement repeatedly (0.5 Hz). Ankle muscle fatigability increased CoP anterior-posterior (AP - p < 0.02) and medial-lateral (ML - p < 0.009) root mean square (RMS), and AP (p < 0.01) mean velocity immediately after compared to before FI. These effects remained after 24/48 h of recovery: higher CoP AP (p < 0.03) and ML (p < 0.009) RMS. No significant effects for detrend fluctuation analysis and entropy analysis among periods of postural evaluations was found. Fatigue*visual condition interaction revealed an increased AP median frequency (p < 0.001) during EC compared to EO only immediately after FI. Young adults' body sway remains impaired until 48 h, but not the postural control adaptability and complexity. Visual information may not attenuate the late deleterious ankle muscle fatigability effects. Individuals should be cautious during balance tasks and exercise after fatiguing exercise in the next 24/48 h, therefore avoiding unbalances and falls.
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Affiliation(s)
- Tiago Penedo
- São Paulo State University (UNESP), School of Sciences, Department of Physical Education, Human Movement Research Laboratory (MOVI-LAB), Bauru, São Paulo, Brazil; University Grenoble Alpes, AGEIS, Grenoble, France.
| | - Nicolas Vuillerme
- University Grenoble Alpes, AGEIS, Grenoble, France; Institut Universitaire de France, France.
| | - Felipe Balistieri Santinelli
- São Paulo State University (UNESP), School of Sciences, Department of Physical Education, Human Movement Research Laboratory (MOVI-LAB), Bauru, São Paulo, Brazil; REVAL Rehabilitation Research Center, Faculty of Rehabilitation Sciences, Hasselt University, Hasselt, Belgium.
| | - Gabriel Felipe Moretto
- São Paulo State University (UNESP), School of Sciences, Department of Physical Education, Human Movement Research Laboratory (MOVI-LAB), Bauru, São Paulo, Brazil.
| | - Elisa de Carvalho Costa
- São Paulo State University (UNESP), School of Sciences, Department of Physical Education, Human Movement Research Laboratory (MOVI-LAB), Bauru, São Paulo, Brazil.
| | - Julia Pilon
- São Paulo State University (UNESP), School of Sciences, Department of Physical Education, Human Movement Research Laboratory (MOVI-LAB), Bauru, São Paulo, Brazil.
| | - Carlos Augusto Kalva-Filho
- São Paulo State University (UNESP), School of Sciences, Department of Physical Education, Human Movement Research Laboratory (MOVI-LAB), Bauru, São Paulo, Brazil.
| | - Fabio A Barbieri
- São Paulo State University (UNESP), School of Sciences, Department of Physical Education, Human Movement Research Laboratory (MOVI-LAB), Bauru, São Paulo, Brazil.
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46
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Eschelmuller G, Chua R, Carpenter MG, Inglis JT. The acute effects of periodic and noisy tendon vibration on wrist muscle stretch responses. Neurosci Lett 2021; 764:136279. [PMID: 34600040 DOI: 10.1016/j.neulet.2021.136279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 09/24/2021] [Accepted: 09/27/2021] [Indexed: 11/25/2022]
Abstract
Mechanical muscle tendon vibration activates multiple sensory receptors in the muscle and tendon. In particular, tendon vibration tends to activate the Ia afferents the strongest, but also will activate group II and Ib afferents. This activation can cause three main effects in the central nervous system: proprioceptive illusions, tonic vibration reflexes, and suppression of the stretch response. Noisy tendon vibration has been used to assess the frequency characteristics of proprioceptive reflexes and, interestingly there appeared to be no evidence for proprioceptive illusions or tonic vibration reflexes during standing [9]. However, it remains unknown if noisy vibration induces a suppression of the muscle stretch response. Therefore, the purpose of this study was to investigate the effects of noisy and periodic tendon vibration on the stretch response in the flexor carpi radialis muscle (FCR). We examined FCR stretch responses with and without periodic (20 and 100 Hz) and noisy (∼10-100 Hz) tendon vibration. We additionally had participants perform the task under the instruction set to either not respond to the perturbation or to respond as fast as possible. The key finding from this study was that both periodic and noisy vibration resulted in a reduced stretch response amplitude. Additionally, it was found that a participant's intent to respond did not modulate the amount of suppression observed. The findings from this study provide a more detailed understanding of the effects of tendon vibration on the muscle stretch response.
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Affiliation(s)
- Gregg Eschelmuller
- School of Kinesiology, University of British Columbia, Vancouver, British Columbia, Canada.
| | - Romeo Chua
- School of Kinesiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Mark G Carpenter
- School of Kinesiology, University of British Columbia, Vancouver, British Columbia, Canada; Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada; International Collaboration on Repair Discoveries, Vancouver, British Columbia, Canada
| | - J Timothy Inglis
- School of Kinesiology, University of British Columbia, Vancouver, British Columbia, Canada
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47
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van 't Veld RC, van Asseldonk EHF, van der Kooij H, Schouten AC. Disentangling acceleration-, velocity-, and duration-dependency of the short- and medium-latency stretch reflexes in the ankle plantarflexors. J Neurophysiol 2021; 126:1015-1029. [PMID: 34406875 DOI: 10.1152/jn.00704.2020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Motorized assessment of the stretch reflex is instrumental to gain understanding of the stretch reflex, its physiological origin and to differentiate effects of neurological disorders, like spasticity. Both short-latency (M1) and medium-latency (M2) stretch reflexes have been reported to depend on the velocity and acceleration of an applied ramp-and-hold perturbation. In the upper limb, M2 has also been reported to depend on stretch duration. However, wrong conclusions might have been drawn in previous studies as the interdependence of perturbation parameters (amplitude, duration, velocity, and acceleration) possibly created uncontrolled, confounding effects. We disentangled the duration-, velocity-, and acceleration-dependence and their interactions of the M1 and M2 stretch reflex in the ankle plantarflexors. To disentangle the parameter interdependence, 49 unique ramp-and-hold joint perturbations elicited reflexes in 10 healthy volunteers during a torque control task. Linear mixed model analysis showed that M1 depended on acceleration, not velocity or duration, whereas M2 depended on acceleration, velocity, and duration. Simulations of the muscle spindle Ia afferents coupled to a motoneuron pool corroborated these experimental findings. In addition, this simulation model did show a nonlinear M1 velocity- and duration-dependence for perturbation parameters outside the experimental scope. In conclusion, motorized assessment of the stretch reflex or spasticity using ramp-and-hold perturbations should be systematically executed and reported. Our systematic motorized and simulation assessments showed that M1 and M2 depend on acceleration, velocity, and duration of the applied perturbation. The simulation model suggested that these dependencies emerge from: muscle-tendon unit and muscle cross-bridge dynamics, Ia sensitivity to force and yank, and motoneuron synchronization.NEW & NOTEWORTHY Previous research and definitions of the stretch reflex and spasticity have focused on velocity-dependence. We showed that perturbation acceleration, velocity, and duration all shape the M1 and M2 response, often via nonlinear or interacting dependencies. Consequently, systematic execution and reporting of stretch reflex and spasticity studies, avoiding uncontrolled parameter interdependence, is essential for proper understanding of the reflex neurophysiology.
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Affiliation(s)
- Ronald C van 't Veld
- Department of Biomechanical Engineering, University of Twente, Enschede, The Netherlands
| | | | - Herman van der Kooij
- Department of Biomechanical Engineering, University of Twente, Enschede, The Netherlands.,Department of Biomechanical Engineering, Delft University of Technology, Delft, The Netherlands
| | - Alfred C Schouten
- Department of Biomechanical Engineering, University of Twente, Enschede, The Netherlands.,Department of Biomechanical Engineering, Delft University of Technology, Delft, The Netherlands
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Nomberg R, Nisky I. Human-in-the-Loop Stability Analysis of Haptic Rendering With Time Delay by Tracking the Roots of the Characteristic Quasi-Polynomial: The Effect of arm Impedance. IEEE Robot Autom Lett 2021. [DOI: 10.1109/lra.2021.3098934] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Novembre G, Iannetti GD. Towards a unified neural mechanism for reactive adaptive behaviour. Prog Neurobiol 2021; 204:102115. [PMID: 34175406 PMCID: PMC7611662 DOI: 10.1016/j.pneurobio.2021.102115] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 06/17/2021] [Accepted: 06/22/2021] [Indexed: 11/27/2022]
Abstract
Surviving in natural environments requires animals to sense sudden events and swiftly adapt behaviour accordingly. The study of such Reactive Adaptive Behaviour (RAB) has been central to a number of research streams, all orbiting around movement science but progressing in parallel, with little cross-field fertilization. We first provide a concise review of these research streams, independently describing four types of RAB: (1) cortico-muscular resonance, (2) stimulus locked response, (3) online motor correction and (4) action stopping. We then highlight remarkable similarities across these four RABs, suggesting that they might be subserved by the same neural mechanism, and propose directions for future research on this topic.
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Affiliation(s)
- Giacomo Novembre
- Neuroscience and Behaviour Laboratory, Istituto Italiano di Tecnologia (IIT), Rome, Italy; Department of Neuroscience, Physiology and Pharmacology, University College London, UK.
| | - Gian Domenico Iannetti
- Neuroscience and Behaviour Laboratory, Istituto Italiano di Tecnologia (IIT), Rome, Italy; Department of Neuroscience, Physiology and Pharmacology, University College London, UK.
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Schaefer LV, Dech S, Aehle M, Bittmann FN. Disgusting odours affect the characteristics of the Adaptive Force in contrast to neutral and pleasant odours. Sci Rep 2021; 11:16410. [PMID: 34385522 PMCID: PMC8361115 DOI: 10.1038/s41598-021-95759-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 07/26/2021] [Indexed: 11/18/2022] Open
Abstract
The olfactomotor system is especially investigated by examining the sniffing in reaction to olfactory stimuli. The motor output of respiratory-independent muscles was seldomly considered regarding possible influences of smells. The Adaptive Force (AF) characterizes the capability of the neuromuscular system to adapt to external forces in a holding manner and was suggested to be more vulnerable to possible interfering stimuli due to the underlying complex control processes. The aim of this pilot study was to measure the effects of olfactory inputs on the AF of the hip and elbow flexors, respectively. The AF of 10 subjects was examined manually by experienced testers while smelling at sniffing sticks with neutral, pleasant or disgusting odours. The reaction force and the limb position were recorded by a handheld device. The results show, inter alia, a significantly lower maximal isometric AF and a significantly higher AF at the onset of oscillations by perceiving disgusting odours compared to pleasant or neutral odours (p < 0.001). The adaptive holding capacity seems to reflect the functionality of the neuromuscular control, which can be impaired by disgusting olfactory inputs. An undisturbed functioning neuromuscular system appears to be characterized by a proper length tension control and by an earlier onset of mutual oscillations during an external force increase. This highlights the strong connection of olfaction and motor control also regarding respiratory-independent muscles.
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Affiliation(s)
- Laura V Schaefer
- Division Regulative Physiology and Prevention, Department Sports and Health Sciences, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476, Potsdam, Germany.
| | - Silas Dech
- Division Regulative Physiology and Prevention, Department Sports and Health Sciences, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476, Potsdam, Germany
| | - Markus Aehle
- Division Regulative Physiology and Prevention, Department Sports and Health Sciences, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476, Potsdam, Germany
| | - Frank N Bittmann
- Division Regulative Physiology and Prevention, Department Sports and Health Sciences, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476, Potsdam, Germany
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