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Vasudevan V, Murthy A, Padhi R. Modeling kinematic variability reveals displacement and velocity based dual control of saccadic eye movements. Exp Brain Res 2024:10.1007/s00221-024-06870-3. [PMID: 38980340 DOI: 10.1007/s00221-024-06870-3] [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: 12/14/2023] [Accepted: 06/01/2024] [Indexed: 07/10/2024]
Abstract
Noise is a ubiquitous component of motor systems that leads to behavioral variability of all types of movements. Nonetheless, systems-based models investigating human movements are generally deterministic and explain only the central tendencies like mean trajectories. In this paper, a novel approach to modeling kinematic variability of movements is presented and tested on the oculomotor system. This approach reconciles the two prominent philosophies of saccade control: displacement-based control versus velocity-based control. This was achieved by quantifying the variability in saccadic eye movements and developing a stochastic model of its control. The proposed stochastic dual model generated significantly better fits of inter-trial variances of the saccade trajectories compared to existing models. These results suggest that the saccadic system can flexibly use the information of both desired displacement and velocity for its control. This study presents a potential framework for investigating computational principles of motor control in the presence of noise utilizing stochastic modeling of kinematic variability.
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Affiliation(s)
- Varsha Vasudevan
- Department of Bioengineering, Indian Institute of Science, Bangalore, 560012, India.
| | - Aditya Murthy
- Department of Bioengineering, Indian Institute of Science, Bangalore, 560012, India
- Centre for Neuroscience, Indian Institute of Science, Bangalore, 560012, India
| | - Radhakant Padhi
- Department of Bioengineering, Indian Institute of Science, Bangalore, 560012, India
- Department of Aerospace Engineering, Indian Institute of Science, Bangalore, 560012, India
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2
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Mosberger AC, Sibener LJ, Chen TX, Rodrigues HFM, Hormigo R, Ingram JN, Athalye VR, Tabachnik T, Wolpert DM, Murray JM, Costa RM. Exploration biases forelimb reaching strategies. Cell Rep 2024; 43:113958. [PMID: 38520691 PMCID: PMC11097405 DOI: 10.1016/j.celrep.2024.113958] [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: 07/10/2023] [Revised: 12/05/2023] [Accepted: 02/28/2024] [Indexed: 03/25/2024] Open
Abstract
The brain can generate actions, such as reaching to a target, using different movement strategies. We investigate how such strategies are learned in a task where perched head-fixed mice learn to reach to an invisible target area from a set start position using a joystick. This can be achieved by learning to move in a specific direction or to a specific endpoint location. As mice learn to reach the target, they refine their variable joystick trajectories into controlled reaches, which depend on the sensorimotor cortex. We show that individual mice learned strategies biased to either direction- or endpoint-based movements. This endpoint/direction bias correlates with spatial directional variability with which the workspace was explored during training. Model-free reinforcement learning agents can generate both strategies with similar correlation between variability during training and learning bias. These results provide evidence that reinforcement of individual exploratory behavior during training biases the reaching strategies that mice learn.
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Affiliation(s)
- Alice C Mosberger
- Departments of Neuroscience and Neurology, Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA.
| | - Leslie J Sibener
- Departments of Neuroscience and Neurology, Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Tiffany X Chen
- Departments of Neuroscience and Neurology, Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Helio F M Rodrigues
- Departments of Neuroscience and Neurology, Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA; Allen Institute, Seattle, WA 98109, USA
| | - Richard Hormigo
- Department of Neuroscience, Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - James N Ingram
- Department of Neuroscience, Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Vivek R Athalye
- Departments of Neuroscience and Neurology, Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Tanya Tabachnik
- Department of Neuroscience, Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Daniel M Wolpert
- Department of Neuroscience, Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - James M Murray
- Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA
| | - Rui M Costa
- Departments of Neuroscience and Neurology, Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA; Allen Institute, Seattle, WA 98109, USA.
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3
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Ferguson LA, Matamales M, Nolan C, Balleine BW, Bertran-Gonzalez J. Adaptation of sequential action benefits from timing variability related to lateral basal ganglia circuitry. iScience 2024; 27:109274. [PMID: 38496293 PMCID: PMC10943431 DOI: 10.1016/j.isci.2024.109274] [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: 07/31/2023] [Revised: 10/11/2023] [Accepted: 02/15/2024] [Indexed: 03/19/2024] Open
Abstract
Streamlined action sequences must remain flexible should stable contingencies in the environment change. By combining analyses of behavioral structure with a circuit-specific manipulation in mice, we report on a relationship between action timing variability and successful adaptation that relates to post-synaptic targets of primary motor cortical (M1) projections to dorsolateral striatum (DLS). In a two-lever instrumental task, mice formed successful action sequences by, first, establishing action scaffolds and, second, smoothly extending action duration to adapt to increased task requirements. Interruption of DLS neurons in M1 projection territories altered this process, evoking higher-rate actions that were more stereotyped in their timing, reducing opportunities for success. Based on evidence from neuronal tracing experiments, we propose that DLS neurons in M1 projection territories supply action timing variability to facilitate adaptation, a function that may involve additional downstream subcortical processing relating to collateralization of descending motor pathways to multiple basal ganglia centers.
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Affiliation(s)
- Lachlan A. Ferguson
- Decision Neuroscience Laboratory, School of Psychology, University of New South Wales, Sydney, NSW, Australia
| | - Miriam Matamales
- Decision Neuroscience Laboratory, School of Psychology, University of New South Wales, Sydney, NSW, Australia
| | - Christopher Nolan
- Decision Neuroscience Laboratory, School of Psychology, University of New South Wales, Sydney, NSW, Australia
| | - Bernard W. Balleine
- Decision Neuroscience Laboratory, School of Psychology, University of New South Wales, Sydney, NSW, Australia
| | - Jesus Bertran-Gonzalez
- Decision Neuroscience Laboratory, School of Psychology, University of New South Wales, Sydney, NSW, Australia
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Mamidanna P, Gholinezhad S, Farina D, Dideriksen JL, Dosen S. Measuring and monitoring skill learning in closed-loop myoelectric hand prostheses using speed-accuracy tradeoffs. J Neural Eng 2024; 21:026008. [PMID: 38417146 DOI: 10.1088/1741-2552/ad2e1c] [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: 08/10/2023] [Accepted: 02/28/2024] [Indexed: 03/01/2024]
Abstract
Objective.Closed-loop myoelectric prostheses, which combine supplementary sensory feedback and electromyography (EMG) based control, hold the potential to narrow the divide between natural and bionic hands. The use of these devices, however, requires dedicated training. Therefore, it is crucial to develop methods that quantify how users acquire skilled control over their prostheses to effectively monitor skill progression and inform the development of interfaces that optimize this process.Approach.Building on theories of skill learning in human motor control, we measured speed-accuracy tradeoff functions (SAFs) to comprehensively characterize learning-induced changes in skill-as opposed to merely tracking changes in task success across training-facilitated by a closed-loop interface that combined proportional control and EMG feedback. Sixteen healthy participants and one individual with a transradial limb loss participated in a three-day experiment where they were instructed to perform the box-and-blocks task using a timed force-matching paradigm at four specified speeds to reach two target force levels, such that the SAF could be determined.Main results.We found that the participants' accuracy increased in a similar way across all speeds we tested. Consequently, the shape of the SAF remained similar across days, at both force levels. Further, we observed that EMG feedback enabled participants to improve their motor execution in terms of reduced trial-by-trial variability, a hallmark of skilled behavior. We then fit a power law model of the SAF, and demonstrated how the model parameters could be used to identify and monitor changes in skill.Significance.We comprehensively characterized how an EMG feedback interface enabled skill acquisition, both at the level of task performance and movement execution. More generally, we believe that the proposed methods are effective for measuring and monitoring user skill progression in closed-loop prosthesis control.
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Affiliation(s)
- Pranav Mamidanna
- Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | - Shima Gholinezhad
- Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
- Department of Orthopedic Surgery, Aalborg University Hospital, Aalborg, Denmark
| | - Dario Farina
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | | | - Strahinja Dosen
- Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
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Criscuolo A, Schwartze M, Kotz SA. Variability allows for adaptation in dynamic environments comment on 'From neural noise to co-adaptability: Rethinking the multifaceted architecture of motor variability' by L. Casartelli, C. Maronati & A. Cavallo. Phys Life Rev 2024; 48:104-105. [PMID: 38176320 DOI: 10.1016/j.plrev.2023.12.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 12/26/2023] [Indexed: 01/06/2024]
Affiliation(s)
- A Criscuolo
- Department of Neuropsychology & Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, 6200 MD, Maastricht, the Netherlands
| | - M Schwartze
- Department of Neuropsychology & Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, 6200 MD, Maastricht, the Netherlands
| | - S A Kotz
- Department of Neuropsychology & Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, 6200 MD, Maastricht, the Netherlands; Department of Neuropsychology, Max Planck Institute for Human Cognitive and Brain Sciences, 04103, Leipzig, Germany.
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Kunavar T, Jamšek M, Avila-Mireles EJ, Rueckert E, Peternel L, Babič J. The Effects of Different Motor Teaching Strategies on Learning a Complex Motor Task. SENSORS (BASEL, SWITZERLAND) 2024; 24:1231. [PMID: 38400387 PMCID: PMC10892071 DOI: 10.3390/s24041231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 02/07/2024] [Accepted: 02/08/2024] [Indexed: 02/25/2024]
Abstract
During the learning of a new sensorimotor task, individuals are usually provided with instructional stimuli and relevant information about the target task. The inclusion of haptic devices in the study of this kind of learning has greatly helped in the understanding of how an individual can improve or acquire new skills. However, the way in which the information and stimuli are delivered has not been extensively explored. We have designed a challenging task with nonintuitive visuomotor perturbation that allows us to apply and compare different motor strategies to study the teaching process and to avoid the interference of previous knowledge present in the naïve subjects. Three subject groups participated in our experiment, where the learning by repetition without assistance, learning by repetition with assistance, and task Segmentation Learning techniques were performed with a haptic robot. Our results show that all the groups were able to successfully complete the task and that the subjects' performance during training and evaluation was not affected by modifying the teaching strategy. Nevertheless, our results indicate that the presented task design is useful for the study of sensorimotor teaching and that the presented metrics are suitable for exploring the evolution of the accuracy and precision during learning.
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Affiliation(s)
- Tjasa Kunavar
- Laboratory for Neromechanics and Biorobotics, Department of Automatics and Biocybernetics, Jožef Stefan Institute, 1000 Ljubljana, Slovenia
- Jožef Stefan International Postgraduate School, Jamova cesta 39, 1000 Ljubljana, Slovenia
| | - Marko Jamšek
- Laboratory for Neromechanics and Biorobotics, Department of Automatics and Biocybernetics, Jožef Stefan Institute, 1000 Ljubljana, Slovenia
| | - Edwin Johnatan Avila-Mireles
- Laboratory for Neromechanics and Biorobotics, Department of Automatics and Biocybernetics, Jožef Stefan Institute, 1000 Ljubljana, Slovenia
| | - Elmar Rueckert
- Chair of Cyber-Physical-Systems, Montauniversität Leoben, 8700 Leoben, Austria
| | - Luka Peternel
- Department of Cognitive Robotics, Delft University of Technology, 2628 CD Delft, The Netherlands
| | - Jan Babič
- Laboratory for Neromechanics and Biorobotics, Department of Automatics and Biocybernetics, Jožef Stefan Institute, 1000 Ljubljana, Slovenia
- Faculty of Electrical Engineering, University of Ljubljana, 1000 Ljubljana, Slovenia
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7
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Ribeiro MTS, Conceição F, Pacheco MM. Proficiency Barrier in Track and Field: Adaptation and Generalization Processes. SENSORS (BASEL, SWITZERLAND) 2024; 24:1000. [PMID: 38339717 PMCID: PMC10857757 DOI: 10.3390/s24031000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Revised: 01/22/2024] [Accepted: 02/02/2024] [Indexed: 02/12/2024]
Abstract
The literature on motor development and training assumes a hierarchy for learning skills-learning the "fundamentals"-that has yet to be empirically demonstrated. The present study addressed this issue by verifying (1) whether this strong hierarchy (i.e., the proficiency barrier) holds between three fundamental skills and three sport skills and (2) considering different transfer processes (generalization/adaptation) that would occur as a result of the existence of this strong hierarchy. Twenty-seven children/adolescents participated in performing the countermovement jump, standing long jump, leap, high jump, long jump, and hurdle transposition. We identified the proficiency barrier in two pairs of tasks (between the countermovement jump and high jump and between the standing long jump and long jump). Nonetheless, the transfer processes were not related to the proficiency barrier. We conclude that the proposed learning hierarchy holds for some tasks. The underlying reason for this is still unknown.
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Affiliation(s)
- M. Teresa S. Ribeiro
- Research Center in Sport Sciences, Health and Human Development (CIDESD), Physical Education and Sport Sciences Department, University of Maia, 4475-690 Maia, Portugal;
- Center for Investigation, Formation, Innovation and Intervention in Sports, Faculty of Sport, University of Porto, 4200-450 Porto, Portugal;
| | - Filipe Conceição
- Center for Investigation, Formation, Innovation and Intervention in Sports, Faculty of Sport, University of Porto, 4200-450 Porto, Portugal;
| | - Matheus M. Pacheco
- Center for Investigation, Formation, Innovation and Intervention in Sports, Faculty of Sport, University of Porto, 4200-450 Porto, Portugal;
- GEDEM, Department of Physical Education, Federal University of Rondônia, Porto Velho 78900-000, Brazil
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8
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Garofolini A, Mickle KJ, McLaughlin P, Taylor SB. Assessing the effects of foot strike patterns and shoe types on the control of leg length and orientation in running. Sci Rep 2024; 14:2220. [PMID: 38278965 PMCID: PMC10817954 DOI: 10.1038/s41598-024-52446-0] [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: 11/15/2023] [Accepted: 01/18/2024] [Indexed: 01/28/2024] Open
Abstract
This research investigates the stabilization of leg length and orientation during the landing phase of running, examining the effects of different footwear and foot strike patterns. Analyzing kinematic data from twenty male long-distance runners, both rearfoot and forefoot strikers, we utilized the Uncontrolled Manifold approach to assess stability. Findings reveal that both leg length and orientation are indeed stabilized during landing, challenging the hypothesis that rearfoot strikers exhibit less variance in deviations than forefoot strikers, and that increased footwear assistance would reduce these deviations. Surprisingly, footwear with a lower minimalist index enhanced post-landing stability, suggesting that cushioning contributes to both force dissipation and leg length stability. The study indicates that both foot strike patterns are capable of effectively reducing task-relevant variance, with no inherent restriction on flexibility for rearfoot strikers. However, there is an indication of potential reliance on footwear for stability. These insights advance our understanding of the biomechanics of running, highlighting the role of footwear in stabilizing leg length and orientation, which has significant implications for running efficiency and injury prevention.
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Affiliation(s)
| | - Karen J Mickle
- School of Environmental and Life Sciences, University of Newcastle, Ourimbah, NSW, Australia
| | - Patrick McLaughlin
- Institute for Health and Sport (IHES), Victoria University, Melbourne, Australia
| | - Simon B Taylor
- Institute for Health and Sport (IHES), Victoria University, Melbourne, Australia
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9
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Lakmazaheri A, Song S, Vuong BB, Biskner B, Kado DM, Collins SH. Optimizing exoskeleton assistance to improve walking speed and energy economy for older adults. J Neuroeng Rehabil 2024; 21:1. [PMID: 38167151 PMCID: PMC10763092 DOI: 10.1186/s12984-023-01287-5] [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: 03/25/2023] [Accepted: 11/29/2023] [Indexed: 01/05/2024] Open
Abstract
BACKGROUND Walking speed and energy economy tend to decline with age. Lower-limb exoskeletons have demonstrated potential to improve either measure, but primarily in studies conducted on healthy younger adults. Promising techniques like optimization of exoskeleton assistance have yet to be tested with older populations, while speed and energy consumption have yet to be simultaneously optimized for any population. METHODS We investigated the effectiveness of human-in-the-loop optimization of ankle exoskeletons with older adults. Ten healthy adults > 65 years of age (5 females; mean age: 72 ± 3 yrs) participated in approximately 240 min of training and optimization with tethered ankle exoskeletons on a self-paced treadmill. Multi-objective human-in-the-loop optimization was used to identify assistive ankle plantarflexion torque patterns that simultaneously improved self-selected walking speed and metabolic rate. The effects of optimized exoskeleton assistance were evaluated in separate trials. RESULTS Optimized exoskeleton assistance improved walking performance for older adults. Both objectives were simultaneously improved; self-selected walking speed increased by 8% (0.10 m/s; p = 0.001) and metabolic rate decreased by 19% (p = 0.007), resulting in a 25% decrease in energetic cost of transport (p = 8e-4) compared to walking with exoskeletons applying zero torque. Compared to younger participants in studies optimizing a single objective, our participants required lower exoskeleton torques, experienced smaller improvements in energy use, and required more time for motor adaptation. CONCLUSIONS Our results confirm that exoskeleton assistance can improve walking performance for older adults and show that multiple objectives can be simultaneously addressed through human-in-the-loop optimization.
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Affiliation(s)
- Ava Lakmazaheri
- Department of Mechanical Engineering, Stanford University, Stanford, CA, USA
| | - Seungmoon Song
- Department of Mechanical Engineering, Stanford University, Stanford, CA, USA
- Department of Mechanical and Industrial Engineering, Northeastern University, Boston, MA, USA
| | - Brian B Vuong
- Department of Mechanical Engineering, Stanford University, Stanford, CA, USA
| | - Blake Biskner
- Department of Mechanical Engineering, Stanford University, Stanford, CA, USA
| | - Deborah M Kado
- Geriatrics Research Education and Clinical Center, Veterans Affairs, Palo Alto, CA, USA
- Department of Medicine, Stanford University, Stanford, CA, USA
| | - Steven H Collins
- Department of Mechanical Engineering, Stanford University, Stanford, CA, USA.
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Hermus J, Doeringer J, Sternad D, Hogan N. Dynamic primitives in constrained action: systematic changes in the zero-force trajectory. J Neurophysiol 2024; 131:1-15. [PMID: 37820017 DOI: 10.1152/jn.00082.2023] [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: 02/22/2023] [Revised: 10/02/2023] [Accepted: 10/05/2023] [Indexed: 10/13/2023] Open
Abstract
Humans substantially outperform robotic systems in tasks that require physical interaction, despite seemingly inferior muscle bandwidth and slow neural information transmission. The control strategies that enable this performance remain poorly understood. To bridge that gap, this study examined kinematically constrained motion as an intermediate step between the widely studied unconstrained motions and sparsely studied physical interactions. Subjects turned a horizontal planar crank in two directions (clockwise and counterclockwise) at three constant target speeds (fast, medium, and very slow) as instructed via visual display. With the hand constrained to move in a circle, nonzero forces against the constraint were measured. This experiment exposed two observations that could not result from mechanics alone but may be attributed to neural control composed of dynamic primitives. A plausible mathematical model of interactive dynamics (mechanical impedance) was assumed and used to "subtract" peripheral neuromechanics. This method revealed a summary of the underlying neural control in terms of motion, a zero-force trajectory. The estimated zero-force trajectories were approximately elliptical and their orientation differed significantly with turning direction; that is consistent with control using oscillations to generate an elliptical zero-force trajectory. However, for periods longer than 2-5 s, motion can no longer be perceived or executed as periodic. Instead, it decomposes into a sequence of submovements, manifesting as increased variability. These quantifiable performance limitations support the hypothesis that humans simplify this constrained-motion task by exploiting at least three primitive dynamic actions: oscillations, submovements, and mechanical impedance.NEW & NOTEWORTHY Control using primitive dynamic actions may explain why human performance is superior to robots despite seemingly inferior "wetware"; however, this also implies limitations. For a crank-turning task, this work quantified two such informative limitations. Force was exerted even though it produced no mechanical work, the underlying zero-force trajectory was roughly elliptical, and its orientation differed with turning direction, evidence of oscillatory control. At slow speeds, speed variability increased substantially, indicating intermittent control via submovements.
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Affiliation(s)
- James Hermus
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
| | | | - Dagmar Sternad
- Departments of Biology, Electrical and Computer Engineering, and Physics, Northeastern University, Boston, Massachusetts, United States
| | - Neville Hogan
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
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Casartelli L, Maronati C, Cavallo A. From neural noise to co-adaptability: Rethinking the multifaceted architecture of motor variability. Phys Life Rev 2023; 47:245-263. [PMID: 37976727 DOI: 10.1016/j.plrev.2023.10.036] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 10/27/2023] [Indexed: 11/19/2023]
Abstract
In the last decade, the source and the functional meaning of motor variability have attracted considerable attention in behavioral and brain sciences. This construct classically combined different levels of description, variable internal robustness or coherence, and multifaceted operational meanings. We provide here a comprehensive review of the literature with the primary aim of building a precise lexicon that goes beyond the generic and monolithic use of motor variability. In the pars destruens of the work, we model three domains of motor variability related to peculiar computational elements that influence fluctuations in motor outputs. Each domain is in turn characterized by multiple sub-domains. We begin with the domains of noise and differentiation. However, the main contribution of our model concerns the domain of adaptability, which refers to variation within the same exact motor representation. In particular, we use the terms learning and (social)fitting to specify the portions of motor variability that depend on our propensity to learn and on our largely constitutive propensity to be influenced by external factors. A particular focus is on motor variability in the context of the sub-domain named co-adaptability. Further groundbreaking challenges arise in the modeling of motor variability. Therefore, in a separate pars construens, we attempt to characterize these challenges, addressing both theoretical and experimental aspects as well as potential clinical implications for neurorehabilitation. All in all, our work suggests that motor variability is neither simply detrimental nor beneficial, and that studying its fluctuations can provide meaningful insights for future research.
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Affiliation(s)
- Luca Casartelli
- Theoretical and Cognitive Neuroscience Unit, Scientific Institute IRCCS E. MEDEA, Italy
| | - Camilla Maronati
- Move'n'Brains Lab, Department of Psychology, Università degli Studi di Torino, Italy
| | - Andrea Cavallo
- Move'n'Brains Lab, Department of Psychology, Università degli Studi di Torino, Italy; C'MoN Unit, Fondazione Istituto Italiano di Tecnologia, Genova, Italy.
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12
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Kimura A, Nakashima H, Inaba Y. Biomechanical role can vary depending on the conditions of the motor task. Hum Mov Sci 2023; 92:103150. [PMID: 37776752 DOI: 10.1016/j.humov.2023.103150] [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: 05/10/2023] [Revised: 08/29/2023] [Accepted: 09/20/2023] [Indexed: 10/02/2023]
Abstract
Expert players in throwing sports may reduce the variability of projectile arrival position by systematically relating release parameters (e.g., release position, velocity, and angular velocity of the projectile). Reducing the variability of the projectile arrival position is often believed to increase the success rate of throwing task, but it may not be always true. Here, we experimentally illustrate that the systematic relationship between release parameters that reduce the variability of the ball arrival position may not increase the number of hitting trials during a throwing task. Furthermore, we demonstrate that the role of the release parameters in increasing successful trials can vary depending on the target size. Each participant threw balls at two different-sized targets (small and large target conditions). Additionally, they alternately threw balls with overhead and sidearm throwing for both the small and large targets. Our results showed that the release position and velocity in the left-right direction reduced the variability of the ball arrival position and increased the successful trials in the small target condition. In the large target condition, the two release parameters reduced the variability of the ball arrival position, but they did not increase the successful trials. Consequently, reducing the variability of the ball arrival position did not always equate to an increase in successful trials, as it depended on the target size. These findings indicate that the role of the release parameters in increasing hitting trials is not constant but varies depending on the condition of the motor task.
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Affiliation(s)
- Arata Kimura
- Department of Sport Science and Research, Japan Institute of Sports Sciences, Japan.
| | - Hirotaka Nakashima
- Department of Sport Science and Research, Japan Institute of Sports Sciences, Japan
| | - Yuki Inaba
- Department of Sport Science and Research, Japan Institute of Sports Sciences, Japan
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13
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Stamps JA, Biro PA. Time-specific convergence and divergence in individual differences in behavior: Theory, protocols and analyzes. Ecol Evol 2023; 13:e10615. [PMID: 38034332 PMCID: PMC10682899 DOI: 10.1002/ece3.10615] [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: 05/21/2023] [Revised: 09/23/2023] [Accepted: 09/29/2023] [Indexed: 12/02/2023] Open
Abstract
Over the years, theoreticians and empiricists working in a wide range of disciplines, including physiology, ethology, psychology, and behavioral ecology, have suggested a variety of reasons why individual differences in behavior might change over time, such that different individuals become more similar (convergence) or less similar (divergence) to one another. Virtually none of these investigators have suggested that convergence or divergence will continue forever, instead proposing that these patterns will be restricted to particular periods over the course of a longer study. However, to date, few empiricists have documented time-specific convergence or divergence, in part because the experimental designs and statistical methods suitable for describing these patterns are not widely known. Here, we begin by reviewing an array of influential hypotheses that predict convergence or divergence in individual differences over timescales ranging from minutes to years, and that suggest how and why such patterns are likely to change over time (e.g., divergence followed by maintenance). Then, we describe experimental designs and statistical methods that can be used to determine if (and when) individual differences converged, diverged, or were maintained at the same level at specific periods during a longitudinal study. Finally, we describe why the concepts described herein help explain the discrepancy between what theoreticians and empiricists mean when they describe the "emergence" of individual differences or personality, how they might be used to study situations in which convergence and divergence patterns alternate over time, and how they might be used to study time-specific changes in other attributes of behavior, including individual differences in intraindividual variability (predictability), or genotypic differences in behavior.
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Affiliation(s)
- Judy A. Stamps
- Department of Evolution and EcologyUniversity of California, DavisDavisCaliforniaUSA
| | - Peter A. Biro
- School of Life and Environmental SciencesDeakin UniversityGeelongVictoriaAustralia
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14
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Lang-Hodge AM, Cooke DF, Marigold DS. The effects of prior exposure to prism lenses on de novo motor skill learning. PLoS One 2023; 18:e0292518. [PMID: 37862342 PMCID: PMC10588867 DOI: 10.1371/journal.pone.0292518] [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: 06/02/2023] [Accepted: 09/23/2023] [Indexed: 10/22/2023] Open
Abstract
Motor learning involves plasticity in a network of brain areas across the cortex and cerebellum. Such traces of learning have the potential to affect subsequent learning of other tasks. In some cases, prior learning can interfere with subsequent learning, but it may be possible to potentiate learning of one task with a prior task if they are sufficiently different. Because prism adaptation involves extensive neuroplasticity, we reasoned that the elevated excitability of neurons could increase their readiness to undergo structural changes, and in turn, create an optimal state for learning a subsequent task. We tested this idea, selecting two different forms of learning tasks, asking whether exposure to a sensorimotor adaptation task can improve subsequent de novo motor skill learning. Participants first learned a new visuomotor mapping induced by prism glasses in which prism strength varied trial-to-trial. Immediately after and the next day, we tested participants on a mirror tracing task, a form of de novo skill learning. Prism-trained and control participants both learned the mirror tracing task, with similar reductions in error and increases in distance traced. Both groups also showed evidence of offline performance gains between the end of day 1 and the start of day 2. However, we did not detect differences between groups. Overall, our results do not support the idea that prism adaptation learning can potentiate subsequent de novo learning. We discuss factors that may have contributed to this result.
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Affiliation(s)
- Annmarie M. Lang-Hodge
- Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Dylan F. Cooke
- Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, British Columbia, Canada
- Institute for Neuroscience and Neurotechnology, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Daniel S. Marigold
- Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, British Columbia, Canada
- Institute for Neuroscience and Neurotechnology, Simon Fraser University, Burnaby, British Columbia, Canada
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15
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Altenburger P, Ambike SS, Haddad JM. Integrating Motor Variability Evaluation Into Movement System Assessment. Phys Ther 2023; 103:pzad075. [PMID: 37364059 DOI: 10.1093/ptj/pzad075] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 01/26/2023] [Accepted: 03/19/2023] [Indexed: 06/28/2023]
Abstract
Common assessment tools for determining therapeutic success in rehabilitation typically focus on task-based outcomes. Task-based outcomes provide some understanding of the individual's functional ability and motor recovery; however, these clinical outcomes may have limited translation to a patient's functional ability in the real world. Limitations arise because (1) the focus on task-based outcome assessment often disregards the complexity of motor behavior, including motor variability, and (2) mobility in highly variable real-world environments requires movement adaptability that is made possible by motor variability. This Perspective argues that incorporating motor variability measures that reflect movement adaptability into routine clinical assessment would enable therapists to better evaluate progress toward optimal and safe real-world mobility. The challenges and opportunities associated with incorporating variability-based assessment of pathological movements are also discussed. This Perspective also indicates that the field of rehabilitation needs to leverage technology to advance the understanding of motor variability and its impact on an individual's ability to optimize movement. IMPACT This Perspective contends that traditional therapeutic assessments do not adequately evaluate the ability of individuals to adapt their movements to the challenges faced when negotiating the dynamic environments encountered during daily life. Assessment of motor variability derived during movement execution can address this issue and provide better insight into a patient's movement stability and maneuverability in the real world. Creating such a shift in motor system assessment would advance understanding of rehabilitative approaches to motor system recovery and intervention.
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Affiliation(s)
- Peter Altenburger
- Department of Physical Therapy, School of Health and Human Sciences, Indiana University, Indianapolis, Indiana, USA
| | - Satyajit S Ambike
- Department of Health & Kinesiology, Purdue University, West Lafayette, Indiana, USA
| | - Jeffrey M Haddad
- Department of Health & Kinesiology, Purdue University, West Lafayette, Indiana, USA
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16
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Søvik O, Tveiten A, Øygarden H, Stokkeland PJ, Hetland HB, Schneider MS, Sandve KO, Altmann M, Hykkerud DL, Ospel J, Goyal M, Ersdal HL, Kurz MW, Hyldmo PK. Virtual reality simulation training in stroke thrombectomy centers with limited patient volume-Simulator performance and patient outcome. Interv Neuroradiol 2023:15910199231198275. [PMID: 37670718 DOI: 10.1177/15910199231198275] [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: 09/07/2023] Open
Abstract
BACKGROUND Virtual reality simulation training may improve the technical skills of interventional radiologists when establishing endovascular thrombectomy at limited-volume stroke centers. The aim of this study was to investigate whether the technical thrombectomy performance of interventional radiologists improved after a defined virtual reality simulator training period. As part of the quality surveillance of clinical practice, we also assessed patient outcomes and thrombectomy quality indicators at the participating centers. METHODS Interventional radiologists and radiology residents from three thrombectomy-capable stroke centers participated in a five months thrombectomy skill-training curriculum on a virtual reality simulator. The simulator automatically registered procedure time, the number of predefined steps that were correctly executed, handling errors, contrast volume, fluoroscopy time, and radiation dose exposure. The design was a before-after study. Two simulated thrombectomy cases were used as pretest and posttest cases, while seven other cases were used for training. Utilizing the Norwegian Stroke Register, we investigated clinical results in thrombectomy during the study period. RESULTS Nineteen interventional radiologists and radiology residents participated in the study. The improvement between pretest and posttest cases was statistically significant for all outcome measures in both simulated cases, except for the contrast volume used in one case. Clinical patient outcomes in all three centers were well within the recommendations from multi-society consensus guidelines. CONCLUSION Performance on the virtual reality simulator improved after training. Virtual reality simulation may improve the learning curve for interventional radiologists in limited-volume thrombectomy centers. No correlation alleged, the clinical data indicates that the centers studied performed thrombectomy in accordance with guideline-recommended standards.
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Affiliation(s)
- Olav Søvik
- Department of Research, Sørlandet Hospital, Kristiansand, Norway
- Faculty of Health Sciences, University of Stavanger, Stavanger, Norway
| | - Arnstein Tveiten
- Department of Neurology, Sørlandet Hospital, Kristiansand, Norway
| | - Halvor Øygarden
- Department of Neurology, Sørlandet Hospital, Kristiansand, Norway
- Faculty of Health and Sport Sciences, University of Agder, Kristiansand, Norway
| | | | - Hanne Brit Hetland
- Department of Research, Section of Biostatistics, Stavanger University Hospital, Stavanger, Norway
| | | | - Knut Olav Sandve
- Department of Radiology, Stavanger University Hospital, Stavanger, Norway
| | - Marianne Altmann
- Department of Neurology, Akershus University Hospital, Lørenskog, Norway
| | - Dan Levi Hykkerud
- Department of Radiology, Akershus University Hospital, Lørenskog, Norway
| | - Johanna Ospel
- Department of Radiology, Basel University Hospital, Basel, Switzerland
- Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada
| | - Mayank Goyal
- Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada
- Diagnostic Imaging, University of Calgary, Calgary, Alberta, Canada
| | | | - Martin Wilhelm Kurz
- Department of Neurology, Neuroscience Research Group, Stavanger University Hospital, Stavanger, Norway
- Department of Clinical Science, University of Bergen, Norway
| | - Per Kristian Hyldmo
- Department of Research, Sørlandet Hospital, Kristiansand, Norway
- Faculty of Health Sciences, University of Stavanger, Stavanger, Norway
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17
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Nah MC, Krotov A, Russo M, Sternad D, Hogan N. Learning to manipulate a whip with simple primitive actions - A simulation study. iScience 2023; 26:107395. [PMID: 37554449 PMCID: PMC10405071 DOI: 10.1016/j.isci.2023.107395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 05/26/2023] [Accepted: 07/11/2023] [Indexed: 08/10/2023] Open
Abstract
This simulation study investigated whether a 4-degrees-of-freedom (DOF) arm could strike a target with a 50-DOF whip using a motion profile similar to discrete human movements. The interactive dynamics of the multi-joint arm was modeled as a constant joint-space mechanical impedance, with values derived from experimental measurement. Targets at various locations could be hit with a single maximally smooth motion in joint-space coordinates. The arm movements that hit the targets were identified with fewer than 250 iterations. The optimal actions were essentially planar arm motions in extrinsic task-space coordinates, predominantly oriented along the most compliant direction of both task-space and joint-space mechanical impedances. Of the optimal movement parameters, striking a target was most sensitive to movement duration. This result suggests that the elementary actions observed in human motor behavior may support efficient motor control in interaction with a dynamically complex object.
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Affiliation(s)
- Moses C. Nah
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Aleksei Krotov
- Department of Bioengineering, Northeastern University, Boston, MA 02115, USA
| | - Marta Russo
- Department of Biology, Northeastern University, Boston, MA 02115, USA
- Department of Neurology, Policlinico Tor Vergata and the Laboratory of Neuromotor Physiology, IRCCS Santa Lucia Foundation, Rome, Italy
| | - Dagmar Sternad
- Department of Biology, Department of Electrical and Computer Engineering, Department of Physics, Institute of Experiential Robotics, Northeastern University, Boston, MA 02115, USA
| | - Neville Hogan
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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18
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Yadav G, Duque J. Reflecting on what is "skill" in human motor skill learning. Front Hum Neurosci 2023; 17:1117889. [PMID: 37484917 PMCID: PMC10356990 DOI: 10.3389/fnhum.2023.1117889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 06/16/2023] [Indexed: 07/25/2023] Open
Abstract
Humans have an exceptional ability to execute a variety of skilled movements. Researchers have been long interested in understanding behavioral and neurophysiological basis of human motor skill learning for advancing both fundamental neuroscientific knowledge and clinical outcomes. However, despite decades of work in this field there is a lack of consensus about what is meant by "skill" in skill learning. With an advent of various task paradigms testing human motor behavior and increasing heterogeneity in motor learning assessments methods, it is very crucial to identify key features of skill in order to avoid any ambiguity that may result in misinterpretation or over-generalization of findings, which could have serious implications for replication and translational research. In this review, we attempt to highlight the features of skill following a historical approach, considering the seminal work that led to the first definitions of skill and including some contemporary concepts emerging from human motor learning research. Overall, based on this literature, we emphasize that skill has some fundamental characteristics, such as- (i) optimal movement selection and execution, (ii) improved movement speed and accuracy, and (iii) reduced movement variability and error. These features of skill can emerge as a consequence of extensive practice/training/learning, thus resulting in an improved performance state beyond baseline levels. Finally we provide some examples of model tasks that can appropriately capture these features of skill, and conclude that any neuroscientific endeavor aimed at understanding the essence of skill in human motor skill learning should focus on these aspects.
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19
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Mulla DM, Keir PJ. Neuromuscular control: from a biomechanist's perspective. Front Sports Act Living 2023; 5:1217009. [PMID: 37476161 PMCID: PMC10355330 DOI: 10.3389/fspor.2023.1217009] [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: 05/04/2023] [Accepted: 06/21/2023] [Indexed: 07/22/2023] Open
Abstract
Understanding neural control of movement necessitates a collaborative approach between many disciplines, including biomechanics, neuroscience, and motor control. Biomechanics grounds us to the laws of physics that our musculoskeletal system must obey. Neuroscience reveals the inner workings of our nervous system that functions to control our body. Motor control investigates the coordinated motor behaviours we display when interacting with our environment. The combined efforts across the many disciplines aimed at understanding human movement has resulted in a rich and rapidly growing body of literature overflowing with theories, models, and experimental paradigms. As a result, gathering knowledge and drawing connections between the overlapping but seemingly disparate fields can be an overwhelming endeavour. This review paper evolved as a need for us to learn of the diverse perspectives underlying current understanding of neuromuscular control. The purpose of our review paper is to integrate ideas from biomechanics, neuroscience, and motor control to better understand how we voluntarily control our muscles. As biomechanists, we approach this paper starting from a biomechanical modelling framework. We first define the theoretical solutions (i.e., muscle activity patterns) that an individual could feasibly use to complete a motor task. The theoretical solutions will be compared to experimental findings and reveal that individuals display structured muscle activity patterns that do not span the entire theoretical solution space. Prevalent neuromuscular control theories will be discussed in length, highlighting optimality, probabilistic principles, and neuromechanical constraints, that may guide individuals to families of muscle activity solutions within what is theoretically possible. Our intention is for this paper to serve as a primer for the neuromuscular control scientific community by introducing and integrating many of the ideas common across disciplines today, as well as inspire future work to improve the representation of neural control in biomechanical models.
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20
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Norup M, Nielsen AL, Bjørndal JR, Wiegel P, Spedden ME, Lundbye-Jensen J. Effects of dynamic and isometric motor practice on position control, force control and corticomuscular coherence in preadolescent children. Hum Mov Sci 2023; 90:103114. [PMID: 37354890 DOI: 10.1016/j.humov.2023.103114] [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: 12/19/2022] [Revised: 04/11/2023] [Accepted: 06/01/2023] [Indexed: 06/26/2023]
Abstract
In this study, we investigated the effects of motor practice with an emphasis on either position or force control on motor performance, motor accuracy and variability in preadolescent children. Furthermore, we investigated corticomuscular coherence and potential changes following motor practice. We designed a setup allowing discrete wrist flexions of the non-dominant hand and tested motor accuracy and variability when the task was to generate specific movement endpoints (15-75 deg) or force levels (5-25% MVC). All participants were tested in both tasks at baseline and post motor practice without augmented feedback on performance. Following baseline assessment, participants (44 children aged 9-11 years) were randomly assigned to either position (PC) or force control (FC) motor practice or a resting control group (CON). The PC and FC groups performed four blocks of 40 trials motor practice with augmented feedback on performance. Following practice, improvements in movement accuracy were significantly greater in the PC group compared to the FC and CON groups (p < 0.001). None of the groups displayed changes in force task performance indicating no benefits of force control motor practice and low transfer between tasks (p-values:0.08-0.45). Corticomuscular coherence (C4-FCR) was demonstrated during the hold phase in both tasks with no difference between tasks. Corticomuscular coherence did not change from baseline to post practice in any group. Our findings demonstrate that preadolescent children improve position control following dynamic accuracy motor practice. Contrary to previous findings in adults, preadolescent children displayed smaller or no improvements in force control following isometric motor practice, low transfer between tasks and no changes in corticomuscular coherence.
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Affiliation(s)
- Malene Norup
- Movement & Neuroscience, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark; Department of Midwifery, Physiotherapy, Occupational Therapy and Psychomotor Therapy, Faculty of Health, University College Copenhagen, Denmark.
| | - August Lomholt Nielsen
- Movement & Neuroscience, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Jonas Rud Bjørndal
- Movement & Neuroscience, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Patrick Wiegel
- Movement & Neuroscience, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Meaghan Elizabeth Spedden
- Movement & Neuroscience, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark; Wellcome Centre for Human Neuroimaging, Queen Square Institute of Neurology, University College London, United Kingdom
| | - Jesper Lundbye-Jensen
- Movement & Neuroscience, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
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21
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Canta AJ, Adas SAE, Washington KN, McAllister T. Variability, accuracy, and cross-linguistic transfer in bilingual children speaking Jamaican Creole and English. CLINICAL LINGUISTICS & PHONETICS 2023; 37:436-453. [PMID: 35672935 PMCID: PMC9726996 DOI: 10.1080/02699206.2022.2074311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 04/25/2022] [Accepted: 04/27/2022] [Indexed: 05/20/2023]
Abstract
Due to the lack of normative data about bilingual speech development and limited availability of diagnostic tools optimised for this population, bilingual children under consideration for speech-language services are at an elevated risk of misdiagnosis. In the absence of validated assessment tools, speech-language pathologists may use measures of accuracy and variability of speech production to diagnose suspected speech sound disorders in bilingual children. Research in general motor development suggests that variability and accuracy may trade off in the course of maturation, whereby movement variability spikes before the transition to a more mature stage of motor control. Such variability-accuracy tradeoffs have been described in monolingual speech development but are understudied in bilingual populations, where cross-linguistic transfer occurs. This study aimed to examine variability, accuracy, and cross-linguistic transfer in the speech of 20 bilingual children speaking Jamaican Creole and English. We hypothesised that children who showed higher accuracy in their productions would also exhibit more variable speech, indicating a variability-accuracy tradeoff. The Word Inconsistency Assessment from the Diagnostic Evaluation of Articulation and Phonology was administered to measure accuracy and variability in the English context, where misdiagnosis is likely to occur. Contrary to our hypothesis, we observed that individuals with higher accuracy tended to be less variable in their productions. Future research should examine longitudinal trajectories of accuracy and variability and consider a more culturally-appropriate definition of 'accuracy' in documenting bilingual speech sound development.
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Affiliation(s)
- Annika J. Canta
- Department of Communicative Sciences and Disorders, New
York University, New York City, USA
| | - Sandy Abu El Adas
- Department of Communicative Sciences and Disorders, New
York University, New York City, USA
| | - Karla N. Washington
- Department of Communicative Sciences and Disorders, New
York University, New York City, USA
- Department of Communication Sciences and Disorders,
University of Cincinnati, Cincinnati, USA
| | - Tara McAllister
- Department of Communicative Sciences and Disorders, New
York University, New York City, USA
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22
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Mosberger AC, Sibener LJ, Chen TX, Rodrigues H, Hormigo R, Ingram JN, Athalye VR, Tabachnik T, Wolpert DM, Murray JM, Costa RM. Exploration biases how forelimb reaches to a spatial target are learned. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.08.539291. [PMID: 37214823 PMCID: PMC10197595 DOI: 10.1101/2023.05.08.539291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The brain can learn to generate actions, such as reaching to a target, using different movement strategies. Understanding how different variables bias which strategies are learned to produce such a reach is important for our understanding of the neural bases of movement. Here we introduce a novel spatial forelimb target task in which perched head-fixed mice learn to reach to a circular target area from a set start position using a joystick. These reaches can be achieved by learning to move into a specific direction or to a specific endpoint location. We find that mice gradually learn to successfully reach the covert target. With time, they refine their initially exploratory complex joystick trajectories into controlled targeted reaches. The execution of these controlled reaches depends on the sensorimotor cortex. Using a probe test with shifting start positions, we show that individual mice learned to use strategies biased to either direction or endpoint-based movements. The degree of endpoint learning bias was correlated with the spatial directional variability with which the workspace was explored early in training. Furthermore, we demonstrate that reinforcement learning model agents exhibit a similar correlation between directional variability during training and learned strategy. These results provide evidence that individual exploratory behavior during training biases the control strategies that mice use to perform forelimb covert target reaches.
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23
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Krajewski KT, Johnson CC, Ahamed NU, Moir GL, Mi Q, Flanagan SD, Anderst WJ, Connaboy C. Recruit-aged adults may preferentially weight task goals over deleterious cost functions during short duration loaded and imposed gait tasks. Sci Rep 2023; 13:4910. [PMID: 36966216 PMCID: PMC10039906 DOI: 10.1038/s41598-023-31972-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 03/20/2023] [Indexed: 03/27/2023] Open
Abstract
Optimal motor control that is stable and adaptable to perturbation is reflected in the temporal arrangement and regulation of gait variability. Load carriage and forced-marching are common military relevant perturbations to gait that have been implicated in the high incidence of musculoskeletal injuries in military populations. We investigated the interactive effects of load magnitude and locomotion pattern on motor variability, stride regulation and spatiotemporal complexity during gait in recruit-aged adults. We further investigated the influences of sex and task duration. Healthy adults executed trials of running and forced-marching with and without loads at 10% above their gait transition velocity. Spatiotemporal parameters were analyzed using a goal equivalent manifold approach. With load and forced-marching, individuals used a greater array of motor solutions to execute the task goal (maintain velocity). Stride-to-stride regulation became stricter as the task progressed. Participants exhibited optimal spatiotemporal complexity with significant but not meaningful differences between sexes. With the introduction of load carriage and forced-marching, individuals relied on a strategy that maximizes and regulates motor solutions that achieve the task goal of velocity specifically but compete with other task functions. The appended cost penalties may have deleterious effects during prolonged execution, potentially increasing the risk of musculoskeletal injuries.
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Affiliation(s)
- Kellen T Krajewski
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA.
| | - Camille C Johnson
- Biodynamics Laboratory, Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA, USA
| | - Nizam U Ahamed
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA
| | - Gavin L Moir
- Exercise Science Department, East Stroudsburg University, East Stroudsburg, PA, USA
| | - Qi Mi
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA
| | - Shawn D Flanagan
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA
| | - William J Anderst
- Biodynamics Laboratory, Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA, USA
| | - Chris Connaboy
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA
- Center for Lower Extremity Ambulatory Research, Rosalind Franklin University of Medicine and Science, North Chicago, IL, USA
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24
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Matsuda N, Abe MO. Error Size Shape Relationships between Motor Variability and Implicit Motor Adaptation. BIOLOGY 2023; 12:biology12030404. [PMID: 36979096 PMCID: PMC10045141 DOI: 10.3390/biology12030404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 03/02/2023] [Indexed: 03/08/2023]
Abstract
Previous studies have demonstrated the effects of motor variability on motor adaptation. However, their findings have been inconsistent, suggesting that various factors affect the relationship between motor variability and adaptation. This study focused on the size of errors driving motor adaptation as one of the factors and examined the relationship between different error sizes. Thirty-one healthy young adults participated in a visuomotor task in which they made fast-reaching movements toward a target. Motor variability was measured in the baseline phase when a veridical feedback cursor was presented. In the adaptation phase, the feedback cursor was sometimes not reflected in the hand position and deviated from the target by 0°, 3°, 6°, or 12° counterclockwise or clockwise (i.e., error-clamp feedback). Movements during trials following trials with error-clamp feedback were measured to quantify implicit adaptation. Implicit adaptation was driven by errors presented through error-clamp feedback. Moreover, motor variability significantly correlated with implicit adaptation driven by a 12° error. The results suggested that motor variability accelerates implicit adaptation when a larger error occurs. As such a trend was not observed when smaller errors occurred, the relationship between motor variability and motor adaptation might have been affected by the error size driving implicit adaptation.
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Affiliation(s)
- Naoyoshi Matsuda
- Graduate School of Education, Hokkaido University, Sapporo 060-0811, Japan
- Correspondence: (N.M.); (M.O.A.); Tel.: +81-11-706-5442 (M.O.A.)
| | - Masaki O. Abe
- Faculty of Education, Hokkaido University, Sapporo 060-0811, Japan
- Correspondence: (N.M.); (M.O.A.); Tel.: +81-11-706-5442 (M.O.A.)
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25
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Malek-Ahmadi M, Duff K, Chen K, Su Y, King JB, Koppelmans V, Schaefer SY. Volumetric regional MRI and neuropsychological predictors of motor task variability in cognitively unimpaired, Mild Cognitive Impairment, and probable Alzheimer's disease older adults. Exp Gerontol 2023; 173:112087. [PMID: 36639062 PMCID: PMC9974847 DOI: 10.1016/j.exger.2023.112087] [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: 09/22/2022] [Revised: 12/24/2022] [Accepted: 01/09/2023] [Indexed: 01/12/2023]
Abstract
INTRODUCTION The mechanisms linking motor function to Alzheimer's disease (AD) progression have not been well studied, despite evidence of AD pathology within motor brain regions. Thus, there is a need for new motor measure that is sensitive and specific to AD. METHODS In a sample of 121 older adults (54 cognitive unimpaired [CU], 35 amnestic Mild Cognitive Impairment [aMCI], and 32 probable mild AD), intrasubject standard deviation (ISD) across six trials of a novel upper-extremity motor task was predicted with volumetric regional gray matter and neuropsychological scores using classification and regression tree (CART) analyses. RESULTS Both gray matter and neuropsychological CART models indicated that motor task ISD (our measure of motor learning) was related to cortical regions and cognitive test scores associated with memory, executive function, and visuospatial skills. CART models also accurately distinguished motor task ISD of MCI and probable mild AD from CU. DISCUSSION Variability in motor task performance across practice trials may be valuable for understanding preclinical and early-stage AD.
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Affiliation(s)
- Michael Malek-Ahmadi
- Banner Alzheimer's Institute, Phoenix, AZ 85006, United States of America; Department of Biomedical Informatics, University of Arizona College of Medicine-Phoenix, Phoenix, AZ 85006, United States of America
| | - Kevin Duff
- Center for Alzheimer's Care, Imaging, & Research, University of Utah, Salt Lake City, UT 84108, United States of America
| | - Kewei Chen
- Banner Alzheimer's Institute, Phoenix, AZ 85006, United States of America
| | - Yi Su
- Banner Alzheimer's Institute, Phoenix, AZ 85006, United States of America
| | - Jace B King
- Center for Alzheimer's Care, Imaging, & Research, University of Utah, Salt Lake City, UT 84108, United States of America
| | - Vincent Koppelmans
- Department of Psychiatry, University of Utah, Salt Lake City, UT 84108, United States of America
| | - Sydney Y Schaefer
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ 85287, United States of America.
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Catenacci Volpi N, Greaves M, Trendafilov D, Salge C, Pezzulo G, Polani D. Skilled motor control of an inverted pendulum implies low entropy of states but high entropy of actions. PLoS Comput Biol 2023; 19:e1010810. [PMID: 36608159 PMCID: PMC9851554 DOI: 10.1371/journal.pcbi.1010810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 01/19/2023] [Accepted: 12/12/2022] [Indexed: 01/07/2023] Open
Abstract
The mastery of skills, such as balancing an inverted pendulum, implies a very accurate control of movements to achieve the task goals. Traditional accounts of skilled action control that focus on either routinization or perceptual control make opposite predictions about the ways we achieve mastery. The notion of routinization emphasizes the decrease of the variance of our actions, whereas the notion of perceptual control emphasizes the decrease of the variance of the states we visit, but not of the actions we execute. Here, we studied how participants managed control tasks of varying levels of difficulty, which consisted of controlling inverted pendulums of different lengths. We used information-theoretic measures to compare the predictions of alternative accounts that focus on routinization and perceptual control, respectively. Our results indicate that the successful performance of the control task strongly correlates with the decrease of state variability and the increase of action variability. As postulated by perceptual control theory, the mastery of skilled pendulum control consists in achieving stable control of goals by flexible means.
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Affiliation(s)
- Nicola Catenacci Volpi
- Department of Computer Science, University of Hertfordshire, Hatfield, England, United Kingdom
- * E-mail:
| | - Martin Greaves
- Department of Computer Science, University of Hertfordshire, Hatfield, England, United Kingdom
| | - Dari Trendafilov
- Institute for Pervasive Computing, Johannes Kepler University, Linz, Austria
| | - Christoph Salge
- Department of Computer Science, University of Hertfordshire, Hatfield, England, United Kingdom
| | - Giovanni Pezzulo
- Institute of Cognitive Sciences and Technologies, National Research Council, Rome, Italy
| | - Daniel Polani
- Department of Computer Science, University of Hertfordshire, Hatfield, England, United Kingdom
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27
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Radhakrishnan U, Chinello F, Koumaditis K. Investigating the effectiveness of immersive VR skill training and its link to physiological arousal. VIRTUAL REALITY 2022; 27:1091-1115. [PMID: 36405878 PMCID: PMC9663202 DOI: 10.1007/s10055-022-00699-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 09/13/2022] [Indexed: 06/05/2023]
Abstract
This paper details the motivations, design, and analysis of a study using a fine motor skill training task in both VR and physical conditions. The objective of this between-subjects study was to (a) investigate the effectiveness of immersive virtual reality for training participants in the 'buzz-wire' fine motor skill task compared to physical training and (b) investigate the link between participants' arousal with their improvements in task performance. Physiological arousal levels in the form of electro-dermal activity (EDA) and ECG (Electrocardiogram) data were collected from 87 participants, randomly distributed across the two conditions. Results indicated that VR training is as good as, or even slightly better than, training in physical training in improving task performance. Moreover, the participants in the VR condition reported an increase in self-efficacy and immersion, while marginally significant differences were observed in the presence and the temporal demand (retrieved from NASA-TLX measurements). Participants in the VR condition showed on average less arousal than those in the physical condition. Though correlation analyses between performance metrics and arousal levels did not depict any statistically significant results, a closer examination of EDA values revealed that participants with lower arousal levels during training, across conditions, demonstrated better improvements in performance than those with higher arousal. These findings demonstrate the effectiveness of VR in training and the potential of using arousal and training performance data for designing adaptive VR training systems. This paper also discusses implications for researchers who consider using biosensors and VR for motor skill experiments. Supplementary Information The online version contains supplementary material available at 10.1007/s10055-022-00699-3.
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Affiliation(s)
- Unnikrishnan Radhakrishnan
- Department of Business Development and Technology, Aarhus University, Birk Centerpark 15, 7400 Herning, Denmark
| | - Francesco Chinello
- Department of Business Development and Technology, Aarhus University, Birk Centerpark 15, 7400 Herning, Denmark
| | - Konstantinos Koumaditis
- Department of Business Development and Technology, Aarhus University, Birk Centerpark 15, 7400 Herning, Denmark
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28
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Zippi EL, You AK, Ganguly K, Carmena JM. Selective modulation of cortical population dynamics during neuroprosthetic skill learning. Sci Rep 2022; 12:15948. [PMID: 36153356 PMCID: PMC9509316 DOI: 10.1038/s41598-022-20218-3] [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: 02/02/2022] [Accepted: 09/09/2022] [Indexed: 01/23/2023] Open
Abstract
Brain-machine interfaces (BMIs) provide a framework for studying how cortical population dynamics evolve over learning in a task in which the mapping between neural activity and behavior is precisely defined. Learning to control a BMI is associated with the emergence of coordinated neural dynamics in populations of neurons whose activity serves as direct input to the BMI decoder (direct subpopulation). While previous work shows differential modification of firing rate modulation in this population relative to a population whose activity was not directly input to the BMI decoder (indirect subpopulation), little is known about how learning-related changes in cortical population dynamics within these groups compare.To investigate this, we monitored both direct and indirect subpopulations as two macaque monkeys learned to control a BMI. We found that while the combined population increased coordinated neural dynamics, this increase in coordination was primarily driven by changes in the direct subpopulation. These findings suggest that motor cortex refines cortical dynamics by increasing neural variance throughout the entire population during learning, with a more pronounced coordination of firing activity in subpopulations that are causally linked to behavior.
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Affiliation(s)
- Ellen L. Zippi
- grid.47840.3f0000 0001 2181 7878Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, CA 94720 USA
| | - Albert K. You
- grid.47840.3f0000 0001 2181 7878Department of Electrical Engineering and Computer Sciences, University of California Berkeley, Berkeley, CA 94720 USA
| | - Karunesh Ganguly
- grid.410372.30000 0004 0419 2775Neurology and Rehabilitation Service, San Francisco VA Medical Center, San Francisco, CA 94121 USA ,grid.266102.10000 0001 2297 6811Department of Neurology, University of California, San Francisco, CA 94143 USA
| | - Jose M. Carmena
- grid.47840.3f0000 0001 2181 7878Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, CA 94720 USA ,grid.47840.3f0000 0001 2181 7878Department of Electrical Engineering and Computer Sciences, University of California Berkeley, Berkeley, CA 94720 USA
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29
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Noise Generation Methods Preserving Image Color Intensity Distributions. CYBERNETICS AND INFORMATION TECHNOLOGIES 2022. [DOI: 10.2478/cait-2022-0031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Abstract
In many visual perception studies, external visual noise is used as a methodology to broaden the understanding of information processing of visual stimuli. The underlying assumption is that two sources of noise limit sensory processing: the external noise inherent in the environmental signals and the internal noise or internal variability at different levels of the neural system. Usually, when external noise is added to an image, it is evenly distributed. However, the color intensity and image contrast are modified in this way, and it is unclear whether the visual system responds to their change or the noise presence. We aimed to develop several methods of noise generation with different distributions that keep the global image characteristics. These methods are appropriate in various applications for evaluating the internal noise in the visual system and its ability to filter the added noise. As these methods destroy the correlation in image intensity of neighboring pixels, they could be used to evaluate the role of local spatial structure in image processing.
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30
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Computational role of exploration noise in error-based de novo motor learning. Neural Netw 2022; 153:349-372. [DOI: 10.1016/j.neunet.2022.06.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 04/23/2022] [Accepted: 06/09/2022] [Indexed: 11/23/2022]
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31
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Nault DR, Mitsuya T, Purcell DW, Munhall KG. Perturbing the consistency of auditory feedback in speech. Front Hum Neurosci 2022; 16:905365. [PMID: 36092651 PMCID: PMC9453207 DOI: 10.3389/fnhum.2022.905365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Accepted: 08/04/2022] [Indexed: 11/13/2022] Open
Abstract
Sensory information, including auditory feedback, is used by talkers to maintain fluent speech articulation. Current models of speech motor control posit that speakers continually adjust their motor commands based on discrepancies between the sensory predictions made by a forward model and the sensory consequences of their speech movements. Here, in two within-subject design experiments, we used a real-time formant manipulation system to explore how reliant speech articulation is on the accuracy or predictability of auditory feedback information. This involved introducing random formant perturbations during vowel production that varied systematically in their spatial location in formant space (Experiment 1) and temporal consistency (Experiment 2). Our results indicate that, on average, speakers’ responses to auditory feedback manipulations varied based on the relevance and degree of the error that was introduced in the various feedback conditions. In Experiment 1, speakers’ average production was not reliably influenced by random perturbations that were introduced every utterance to the first (F1) and second (F2) formants in various locations of formant space that had an overall average of 0 Hz. However, when perturbations were applied that had a mean of +100 Hz in F1 and −125 Hz in F2, speakers demonstrated reliable compensatory responses that reflected the average magnitude of the applied perturbations. In Experiment 2, speakers did not significantly compensate for perturbations of varying magnitudes that were held constant for one and three trials at a time. Speakers’ average productions did, however, significantly deviate from a control condition when perturbations were held constant for six trials. Within the context of these conditions, our findings provide evidence that the control of speech movements is, at least in part, dependent upon the reliability and stability of the sensory information that it receives over time.
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Affiliation(s)
- Daniel R. Nault
- Department of Psychology, Queen’s University, Kingston, ON, Canada
- *Correspondence: Daniel R. Nault,
| | - Takashi Mitsuya
- School of Communication Sciences and Disorders, Western University, London, ON, Canada
- National Centre for Audiology, Western University, London, ON, Canada
| | - David W. Purcell
- School of Communication Sciences and Disorders, Western University, London, ON, Canada
- National Centre for Audiology, Western University, London, ON, Canada
| | - Kevin G. Munhall
- Department of Psychology, Queen’s University, Kingston, ON, Canada
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32
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Hossner EJ, Zahno S. Beyond task-space exploration: On the role of variance for motor control and learning. Front Psychol 2022; 13:935273. [PMID: 35928415 PMCID: PMC9343798 DOI: 10.3389/fpsyg.2022.935273] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 07/04/2022] [Indexed: 11/13/2022] Open
Abstract
This conceptual analysis on the role of variance for motor control and learning should be taken as a call to: (a) overcome the classic motor-action controversy by identifying converging lines and mutual synergies in the explanation of motor behavior phenomena, and (b) design more empirical research on low-level operational aspects of motor behavior rather than on high-level theoretical terms. Throughout the paper, claim (a) is exemplified by deploying the well-accepted task-space landscape metaphor. This approach provides an illustration not only of a dynamical sensorimotor system but also of a structure of internal forward models, as they are used in more cognitively rooted frameworks such as the theory of optimal feedback control. Claim (b) is put into practice by, mainly theoretically, substantiating a number of predictions for the role of variance in motor control and learning that can be derived from a convergent perspective. From this standpoint, it becomes obvious that variance is neither generally “good” nor generally “bad” for sensorimotor learning. Rather, the predictions derived suggest that specific forms of variance cause specific changes on permanent performance. In this endeavor, Newell’s concept of task-space exploration is identified as a fundamental learning mechanism. Beyond, we highlight further predictions regarding the optimal use of variance for learning from a converging view. These predictions regard, on the one hand, additional learning mechanisms based on the task-space landscape metaphor—namely task-space formation, task-space differentiation and task-space (de-)composition—and, on the other hand, mechanisms of meta-learning that refer to handling noise as well as learning-to-learn and learning-to-adapt. Due to the character of a conceptual-analysis paper, we grant ourselves the right to be highly speculative on some issues. Thus, we would like readers to see our call mainly as an effort to stimulate both a meta-theoretical discussion on chances for convergence between classically separated lines of thought and, on an empirical level, future research on the role of variance in motor control and learning.
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33
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Wang H, Max L. Inter-Trial Formant Variability in Speech Production Is Actively Controlled but Does Not Affect Subsequent Adaptation to a Predictable Formant Perturbation. Front Hum Neurosci 2022; 16:890065. [PMID: 35874163 PMCID: PMC9300893 DOI: 10.3389/fnhum.2022.890065] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Accepted: 06/14/2022] [Indexed: 11/13/2022] Open
Abstract
Despite ample evidence that speech production is associated with extensive trial-to-trial variability, it remains unclear whether this variability represents merely unwanted system noise or an actively regulated mechanism that is fundamental for maintaining and adapting accurate speech movements. Recent work on upper limb movements suggest that inter-trial variability may be not only actively regulated based on sensory feedback, but also provide a type of workspace exploration that facilitates sensorimotor learning. We therefore investigated whether experimentally reducing or magnifying inter-trial formant variability in the real-time auditory feedback during speech production (a) leads to adjustments in formant production variability that compensate for the manipulation, (b) changes the temporal structure of formant adjustments across productions, and (c) enhances learning in a subsequent adaptation task in which a predictable formant-shift perturbation is applied to the feedback signal. Results show that subjects gradually increased formant variability in their productions when hearing auditory feedback with reduced variability, but subsequent formant-shift adaptation was not affected by either reducing or magnifying the perceived variability. Thus, findings provide evidence for speakers’ active control of inter-trial formant variability based on auditory feedback from previous trials, but–at least for the current short-term experimental manipulation of feedback variability–not for a role of this variability regulation mechanism in subsequent auditory-motor learning.
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Affiliation(s)
- Hantao Wang
- Department of Speech and Hearing Sciences, University of Washington, Seattle, WA, United States
| | - Ludo Max
- Department of Speech and Hearing Sciences, University of Washington, Seattle, WA, United States
- Haskins Laboratories, New Haven, CT, United States
- *Correspondence: Ludo Max,
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34
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Nair A, Horiguchi I, Fukumori K, Kino-oka M. Development of instability analysis for the filling process of human-induced pluripotent stem cell products. Biochem Eng J 2022. [DOI: 10.1016/j.bej.2022.108506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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35
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Pang B, Cui L, Jiang ZP. Human motor learning is robust to control-dependent noise. BIOLOGICAL CYBERNETICS 2022; 116:307-325. [PMID: 35239005 DOI: 10.1007/s00422-022-00922-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 02/06/2022] [Indexed: 06/14/2023]
Abstract
Noises are ubiquitous in sensorimotor interactions and contaminate the information provided to the central nervous system (CNS) for motor learning. An interesting question is how the CNS manages motor learning with imprecise information. Integrating ideas from reinforcement learning and adaptive optimal control, this paper develops a novel computational mechanism to explain the robustness of human motor learning to the imprecise information, caused by control-dependent noise that exists inherently in the sensorimotor systems. Starting from an initial admissible control policy, in each learning trial the mechanism collects and uses the noisy sensory data (caused by the control-dependent noise) to form an imprecise evaluation of the performance of the current policy and then constructs an updated policy based on the imprecise evaluation. As the number of learning trials increases, the generated policies mathematically provably converge to a (potentially small) neighborhood of the optimal policy under mild conditions, despite the imprecise information in the learning process. The mechanism directly synthesizes the policies from the sensory data, without identifying an internal forward model. Our preliminary computational results on two classic arm reaching tasks are in line with experimental observations reported in the literature. The model-free control principle proposed in the paper sheds more lights into the inherent robustness of human sensorimotor systems to the imprecise information, especially control-dependent noise, in the CNS.
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Affiliation(s)
- Bo Pang
- Department of Electrical and Computer Engineering, New York University, 370 Jay Street, Brooklyn, NY, 11201, USA.
| | - Leilei Cui
- Department of Electrical and Computer Engineering, New York University, 370 Jay Street, Brooklyn, NY, 11201, USA
| | - Zhong-Ping Jiang
- Department of Electrical and Computer Engineering, New York University, 370 Jay Street, Brooklyn, NY, 11201, USA
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36
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Abram SJ, Poggensee KL, Sánchez N, Simha SN, Finley JM, Collins SH, Donelan JM. General variability leads to specific adaptation toward optimal movement policies. Curr Biol 2022; 32:2222-2232.e5. [PMID: 35537453 PMCID: PMC9504978 DOI: 10.1016/j.cub.2022.04.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Revised: 02/03/2022] [Accepted: 04/07/2022] [Indexed: 01/29/2023]
Abstract
Our nervous systems can learn optimal control policies in response to changes to our bodies, tasks, and movement contexts. For example, humans can learn to adapt their control policy in walking contexts where the energy-optimal policy is shifted along variables such as step frequency or step width. However, it is unclear how the nervous system determines which ways to adapt its control policy. Here, we asked how human participants explore through variations in their control policy to identify more optimal policies in new contexts. We created new contexts using exoskeletons that apply assistive torques to each ankle at each walking step. We analyzed four variables that spanned the levels of the whole movement, the joint, and the muscle: step frequency, ankle angle range, total soleus activity, and total medial gastrocnemius activity. We found that, across all of these analyzed variables, variability increased upon initial exposure to new contexts and then decreased with experience. This led to adaptive changes in the magnitude of specific variables, and these changes were correlated with reduced energetic cost. The timescales by which adaptive changes progressed and variability decreased were faster for some variables than others, suggesting a reduced search space within which the nervous system continues to optimize its policy. These collective findings support the principle that exploration through general variability leads to specific adaptation toward optimal movement policies.
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Affiliation(s)
- Sabrina J. Abram
- School of Engineering Science, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | | | - Natalia Sánchez
- Division of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, CA 90089, USA
| | - Surabhi N. Simha
- Department of Biomedical Engineering, Emory University, Atlanta, GA 30322, USA
| | - James M. Finley
- Division of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, CA 90089, USA,Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA,Neuroscience Graduate Program, University of Southern California, Los Angeles, CA 90089, USA
| | - Steven H. Collins
- Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA
| | - J. Maxwell Donelan
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC V5A 1S6, Canada,Twitter: @maxdonelan,Lead contact,Correspondence:
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37
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Waite L, Stewart M, Sackiriyas KSB, Jayawickrema J, Almonroeder TG. Female Athletes Exhibit Greater Trial-to-Trial Coordination Variability When Provided with Instructions Promoting an External Focus. J Mot Behav 2022; 54:686-693. [PMID: 35477341 DOI: 10.1080/00222895.2022.2067517] [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: 10/18/2022]
Abstract
The purpose of this study was to examine how instructions promoting different attentional foci influence joint coordination patterns and trial-to-trial coordination variability during landing. Sixteen females performed drop landings with their typical technique (baseline) and after receiving instructions promoting an internal focus and an external focus. The coordination patterns, and trial-to-trial coordination variability, of the sagittal plane hip-knee, hip-ankle, and knee-ankle angle pairings were compared across conditions. While there was no difference in the joint coordination patterns among the conditions, subjects exhibited greater hip-ankle and knee-ankle trial-to-trial coordination variability for the external focus condition, vs. the baseline and internal focus conditions, which may help to explain the improved motor learning outcomes for athletes who train with an external focus.
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Affiliation(s)
- Lindsey Waite
- Department of Health Professions, University of Wisconsin-La Crosse, La Crosse, WI, USA
| | - Molly Stewart
- Department of Health Professions, University of Wisconsin-La Crosse, La Crosse, WI, USA
| | | | - Jithmie Jayawickrema
- College of Health Professions, Trine University, Fort Wayne, IN, USA.,Outpatient Physical Therapy, Parkview TherapyONE, Fort Wayne, IN, USA
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38
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Lafe CW, Newell KM. Instructions on Task Constraints Mediate Perceptual-Motor Search and How Movement Variability Relates to Performance Outcome. J Mot Behav 2022; 54:669-685. [PMID: 35440288 DOI: 10.1080/00222895.2022.2063787] [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: 10/18/2022]
Abstract
Movement variability has been postulated to afford perception of the perceptual motor workspace and to be directly linked to improved performance. Here, we investigated how instructions mediate the search process and the relation between performance outcome and movement variability. We used a novel bimanual force tracking task where zero error was achieved via proportional output between the hands. Participants were either instructed or not as to how to coordinate their force output to achieve this goal, but the goal to minimize error was explained to all participants. The provision of instructions restricted the overall area of the task space that was searched. Moreover, the time dependent properties of the search were influenced; where instructions increased the likelihood that participants would produce a higher force level over practice. Multiple regression revealed that variability was positively correlated with performance outcome, but the strength of this relation was dependent on instructions and individual search strategies. The findings are consistent with the view that information through instructions shapes individual emergent perceptual-motor search strategies that in turn mediate how movement variability relates to performance outcome.
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Affiliation(s)
- Charley W Lafe
- Department of Kinesiology, University of Georgia, Athens, GA, USA
| | - Karl M Newell
- Department of Kinesiology, University of Georgia, Athens, GA, USA
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39
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Vandevoorde K, Vollenkemper L, Schwan C, Kohlhase M, Schenck W. Using Artificial Intelligence for Assistance Systems to Bring Motor Learning Principles into Real World Motor Tasks. SENSORS 2022; 22:s22072481. [PMID: 35408094 PMCID: PMC9002555 DOI: 10.3390/s22072481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 03/18/2022] [Accepted: 03/20/2022] [Indexed: 11/03/2022]
Abstract
Humans learn movements naturally, but it takes a lot of time and training to achieve expert performance in motor skills. In this review, we show how modern technologies can support people in learning new motor skills. First, we introduce important concepts in motor control, motor learning and motor skill learning. We also give an overview about the rapid expansion of machine learning algorithms and sensor technologies for human motion analysis. The integration between motor learning principles, machine learning algorithms and recent sensor technologies has the potential to develop AI-guided assistance systems for motor skill training. We give our perspective on this integration of different fields to transition from motor learning research in laboratory settings to real world environments and real world motor tasks and propose a stepwise approach to facilitate this transition.
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40
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Du Y, Krakauer JW, Haith AM. The relationship between habits and motor skills in humans. Trends Cogn Sci 2022; 26:371-387. [DOI: 10.1016/j.tics.2022.02.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 02/01/2022] [Accepted: 02/06/2022] [Indexed: 12/18/2022]
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41
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Famié S, Ammi M, Bourdin V, Amorim MA. Evidence for an internal model of friction when controlling kinetic energy at impact to slide an object along a surface toward a target. PLoS One 2022; 17:e0264370. [PMID: 35202414 PMCID: PMC8870541 DOI: 10.1371/journal.pone.0264370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 02/09/2022] [Indexed: 11/18/2022] Open
Abstract
Although the role of an internal model of gravity for the predictive control of the upper limbs is quite well established, evidence is lacking regarding an internal model of friction. In this study, 33 male and female human participants performed a striking movement (with the index finger) to slide a plastic cube-like object to a given target distance. The surface material (aluminum or balsa wood) on which the object slides, the surface slope (-10°, 0, or +10°) and the target distance (25 cm or 50 cm) varied across conditions, with ten successive trials in each condition. Analysis of the object speed at impact and spatial error suggests that: 1) the participants chose to impart a similar speed to the object in the first trial regardless of the surface material to facilitate the estimation of the coefficient of friction; 2) the movement is parameterized across repetitions to reduce spatial error; 3) an internal model of friction can be generalized when the slope changes. Biomechanical analysis showed interindividual variability in the recruitment of the upper limb segments and in the adjustment of finger speed at impact in order to transmit the kinetic energy required to slide the object to the target distance. In short, we provide evidence that the brain builds an internal model of friction that makes it possible to parametrically control a striking movement in order to regulate the amount of kinetic energy required to impart the appropriate initial speed to the object.
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Affiliation(s)
- Sylvain Famié
- Université Paris-Saclay, CIAMS, Orsay, France
- Université d’Orléans, CIAMS, Orléans, France
- Université Paris-Saclay, CNRS, LIMSI, Orsay, France
- Université Paris 8, LIASD, Saint-Denis, France
- * E-mail:
| | - Mehdi Ammi
- Université Paris 8, LIASD, Saint-Denis, France
| | | | - Michel-Ange Amorim
- Université Paris-Saclay, CIAMS, Orsay, France
- Université d’Orléans, CIAMS, Orléans, France
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42
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Kozlowska K, Latka M, West BJ. Persistence and anti-persistence in treadmill walking. Gait Posture 2022; 92:36-43. [PMID: 34808517 DOI: 10.1016/j.gaitpost.2021.10.047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 09/15/2021] [Accepted: 10/30/2021] [Indexed: 02/02/2023]
Abstract
BACKGROUND Strong, long-range persistent correlations in stride time (ST) and length (SL) are the fundamental traits of treadmill gait. Our recent work showed that the ST and SL time series' statistical properties originated from the superposition of large-scale trends and small-scale fluctuations (residuals). Trends served as the control manifolds about which ST and SL fluctuated. RESEARCH QUESTION Do random changes in treadmill belt speed affect the trend properties and ST/SL scaling exponents? METHODS We used Multivariate Adaptive Regression Splines (MARS) to determine gait trends during a walk on a treadmill whose belt speed was perturbed by a strong random noise (coefficient of variation was equal to 0.075, 0.1, and 0.13 for treadmill speed 0.8 m/s, 1.2 m/s, and 1.6 m/s, respectively). Then, we calculated the ST/SL scaling exponents of the experimental time series and the corresponding MARS residuals with the madogram estimator. RESULTS Except for the ST at the lowest treadmill speed, the normalized trend duration was at least two times greater than that for the unperturbed walk. The Cauchy distribution scale parameter, which served as a measure of the width of SL and ST trend slope distributions, was at v=1.2m/s, almost 50% and 25% smaller than the unperturbed values. The differences were even greater at v=1.6 m/s: 73% and 83%. Apart from ST at v=0.8m/s, the ST/SL scaling indices were close to 0.5. For all speeds, the ST and SL MARS residuals were strongly anti-persistent. At v=1.2m/s, the corresponding scaling exponents were equal to 0.37±0.10 and 0.25±0.09. SIGNIFICANCE At normal and moderate treadmill speeds, in the presence of random belt speed perturbations, strongly anti-persistent fluctuations about gentle, persistent trends can lead to weak persistence/antipersistence of ST/SL time series.
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Affiliation(s)
- Klaudia Kozlowska
- Department of Biomedical Engineering, Wroclaw University of Science and Technology, Faculty of Fundamental Problems of Technology, Wroclaw, 50-370, Poland
| | - Miroslaw Latka
- Department of Biomedical Engineering, Wroclaw University of Science and Technology, Faculty of Fundamental Problems of Technology, Wroclaw, 50-370, Poland.
| | - Bruce J West
- Office of the Director, Army Research Office, Research Triangle Park, 27709, USA
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User intent estimation during robot learning using physical human robot interaction primitives. Auton Robots 2022. [DOI: 10.1007/s10514-021-10030-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
AbstractAs robotic systems transition from traditional setups to collaborative work spaces, the prevalence of physical Human Robot Interaction has risen in both industrial and domestic environments. A popular representation for robot behavior is movement primitives which learn, imitate, and generalize from expert demonstrations. While there are existing works in context-aware movement primitives, they are usually limited to contact-free human robot interactions. This paper presents physical Human Robot Interaction Primitives (pHRIP), which utilize only the interaction forces between the human user and robot to estimate user intent and generate the appropriate robot response during physical human robot interactions. The efficacy of pHRIP is evaluated through multiple experiments based on target-directed reaching and obstacle avoidance tasks using a real seven degree of freedom robot arm. The results are validated against Interaction Primitives which use observations of robotic trajectories, with discussions of future pHRI applications utilizing pHRIP.
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Pagano M, Stochino G, Casadio M, Ranganathan R. Motor Memory Consolidation after Augmented Variability Depends on the Space in which Variability is Introduced. Neuroscience 2021; 479:169-179. [PMID: 34755613 DOI: 10.1016/j.neuroscience.2021.10.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 10/21/2021] [Accepted: 10/24/2021] [Indexed: 11/17/2022]
Abstract
Motor memories undergo a period of consolidation before they become resistant to the practice of another task. Although movement variability is important in motor memory consolidation, its role is not fully understood in redundant tasks where variability can exist along two orthogonal subspaces (the 'task space' and the 'null space') that have different effects on task performance. Here, we used haptic perturbations to augment variability in these different spaces and examined their effect on motor memory consolidation. Participants learned a shuffleboard task, where they held a bimanual manipulandum and made a discrete throwing motion to slide a virtual puck towards a target. The task was redundant because the distance travelled by the puck was determined by the sum of the left and right hand speeds at release. After participants practiced the task, we used haptic perturbations to introduce motor variability in the task space or null space and examined consolidation of the original task on the next day. We found that regardless of the amplitude, augmenting variability in the task space resulted in significantly better consolidation relative to augmenting variability in the null space, but was not different from a control group that practiced with no variability. This benefit of increasing task space variability relative to increasing null space variability was likely due to the fact that it did not disrupt the pre-existing coordination strategy. These results suggest that the effects of variability on motor memory consolidation depend on the interplay between the induced variability and the pre-existing coordination strategy.
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Affiliation(s)
- Mattia Pagano
- Department of Informatics, Bioengineering, Robotics and Systems Engineering, University of Genova, Genova, Italy
| | - Gaia Stochino
- Department of Informatics, Bioengineering, Robotics and Systems Engineering, University of Genova, Genova, Italy
| | - Maura Casadio
- Department of Informatics, Bioengineering, Robotics and Systems Engineering, University of Genova, Genova, Italy
| | - Rajiv Ranganathan
- Department of Kinesiology, Michigan State University, East Lansing, MI, USA; Deparment of Mechanical Engineering, Michigan State University, East Lansing, MI, USA.
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Lee J, Huber ME, Hogan N. Applying Hip Stiffness With an Exoskeleton to Compensate Gait Kinematics. IEEE Trans Neural Syst Rehabil Eng 2021; 29:2645-2654. [PMID: 34871174 DOI: 10.1109/tnsre.2021.3132621] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Neurological disorders and aging induce impaired gait kinematics. Despite recent advances, effective methods using lower-limb exoskeleton robots to restore gait kinematics are as yet limited. In this study, applying virtual stiffness using a hip exoskeleton was investigated as a possible method to guide users to change their gait kinematics. With a view to applications in locomotor rehabilitation, either to provide assistance or promote recovery, this study assessed whether imposed stiffness induced changes in the gait pattern during walking; and whether any changes persisted upon removal of the intervention, which would indicate changes in central neuro-motor control. Both positive and negative stiffness induced immediate and persistent changes of gait kinematics. However, the results showed little behavioral evidence of persistent changes in neuro-motor control, not even short-lived aftereffects. In addition, stride duration was little affected, suggesting that at least two dissociable layers exist in the neuro-motor control of human walking. The lack of neuro-motor adaptation suggests that, within broad limits, the central nervous system is surprisingly indifferent to the details of lower limb kinematics. The lack of neuro-motor adaptation also suggests that alternative methods may be required to implement a therapeutic technology to promote recovery. However, the immediate, significant, and reproducible changes in kinematics suggest that applying hip stiffness with an exoskeleton may be an effective assistive technology for compensation.
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Rothwell J, Antal A, Burke D, Carlsen A, Georgiev D, Jahanshahi M, Sternad D, Valls-Solé J, Ziemann U. Central nervous system physiology. Clin Neurophysiol 2021; 132:3043-3083. [PMID: 34717225 PMCID: PMC8863401 DOI: 10.1016/j.clinph.2021.09.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 09/13/2021] [Accepted: 09/20/2021] [Indexed: 12/15/2022]
Abstract
This is the second chapter of the series on the use of clinical neurophysiology for the study of movement disorders. It focusses on methods that can be used to probe neural circuits in brain and spinal cord. These include use of spinal and supraspinal reflexes to probe the integrity of transmission in specific pathways; transcranial methods of brain stimulation such as transcranial magnetic stimulation and transcranial direct current stimulation, which activate or modulate (respectively) the activity of populations of central neurones; EEG methods, both in conjunction with brain stimulation or with behavioural measures that record the activity of populations of central neurones; and pure behavioural measures that allow us to build conceptual models of motor control. The methods are discussed mainly in relation to work on healthy individuals. Later chapters will focus specifically on changes caused by pathology.
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Affiliation(s)
- John Rothwell
- Department of Clinical and Movement Neuroscience, UCL Queen Square Institute of Neurology, London, UK,Corresponding author at: Department of Clinical and Movement Neuroscience, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK, (J. Rothwell)
| | - Andrea Antal
- Department of Neurology, University Medical Center Göttingen, Germany
| | - David Burke
- Department of Neurology, Royal Prince Alfred Hospital, University of Sydney, Sydney 2050, Australia
| | - Antony Carlsen
- School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - Dejan Georgiev
- Department of Neurology, University Medical Centre Ljubljana, Slovenia
| | - Marjan Jahanshahi
- Department of Clinical and Movement Neuroscience, UCL Queen Square Institute of Neurology, London, UK
| | - Dagmar Sternad
- Departments of Biology, Electrical & Computer Engineering, and Physics, Northeastern University, Boston, MA 02115, USA
| | - Josep Valls-Solé
- Institut d’Investigació Biomèdica August Pi I Sunyer, Villarroel, 170, Barcelona, Spain
| | - Ulf Ziemann
- Department of Neurology and Stroke, and Hertie Institute for Clinical Brain Research, Eberhard Karls University, Tübingen, Germany
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Nayeem R, Bazzi S, Sadeghi M, Hogan N, Sternad D. Preparing to move: Setting initial conditions to simplify interactions with complex objects. PLoS Comput Biol 2021; 17:e1009597. [PMID: 34919539 PMCID: PMC8683040 DOI: 10.1371/journal.pcbi.1009597] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 10/28/2021] [Indexed: 12/15/2022] Open
Abstract
Humans dexterously interact with a variety of objects, including those with complex internal dynamics. Even in the simple action of carrying a cup of coffee, the hand not only applies a force to the cup, but also indirectly to the liquid, which elicits complex reaction forces back on the hand. Due to underactuation and nonlinearity, the object's dynamic response to an action sensitively depends on its initial state and can display unpredictable, even chaotic behavior. With the overarching hypothesis that subjects strive for predictable object-hand interactions, this study examined how subjects explored and prepared the dynamics of an object for subsequent execution of the target task. We specifically hypothesized that subjects find initial conditions that shorten the transients prior to reaching a stable and predictable steady state. Reaching a predictable steady state is desirable as it may reduce the need for online error corrections and facilitate feed forward control. Alternative hypotheses were that subjects seek to reduce effort, increase smoothness, and reduce risk of failure. Motivated by the task of 'carrying a cup of coffee', a simplified cup-and-ball model was implemented in a virtual environment. Human subjects interacted with this virtual object via a robotic manipulandum that provided force feedback. Subjects were encouraged to first explore and prepare the cup-and-ball before initiating a rhythmic movement at a specified frequency between two targets without losing the ball. Consistent with the hypotheses, subjects increased the predictability of interaction forces between hand and object and converged to a set of initial conditions followed by significantly decreased transients. The three alternative hypotheses were not supported. Surprisingly, the subjects' strategy was more effortful and less smooth, unlike the observed behavior in simple reaching movements. Inverse dynamics of the cup-and-ball system and forward simulations with an impedance controller successfully described subjects' behavior. The initial conditions chosen by the subjects in the experiment matched those that produced the most predictable interactions in simulation. These results present first support for the hypothesis that humans prepare the object to minimize transients and increase stability and, overall, the predictability of hand-object interactions.
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Affiliation(s)
- Rashida Nayeem
- Department of Electrical and Computer Engineering, Northeastern University, Boston, Massachusetts, United States of America
| | - Salah Bazzi
- Department of Electrical and Computer Engineering, Northeastern University, Boston, Massachusetts, United States of America
- Department of Biology, Northeastern University, Boston, Massachusetts, United States of America
- Institute for Experiential Robotics, Northeastern University, Boston, Massachusetts, United States of America
| | - Mohsen Sadeghi
- Department of Electrical and Computer Engineering, Northeastern University, Boston, Massachusetts, United States of America
- Department of Biology, Northeastern University, Boston, Massachusetts, United States of America
| | - Neville Hogan
- Departments of Mechanical Engineering and Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Dagmar Sternad
- Department of Electrical and Computer Engineering, Northeastern University, Boston, Massachusetts, United States of America
- Department of Biology, Northeastern University, Boston, Massachusetts, United States of America
- Institute for Experiential Robotics, Northeastern University, Boston, Massachusetts, United States of America
- Department of Physics, Northeastern University, Boston, Massachusetts, United States of America
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Bayani KYT, Natraj N, Khresdish N, Pargeter J, Stout D, Wheaton LA. Emergence of perceptuomotor relationships during paleolithic stone toolmaking learning: intersections of observation and practice. Commun Biol 2021; 4:1278. [PMID: 34764417 PMCID: PMC8585878 DOI: 10.1038/s42003-021-02768-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 10/11/2021] [Indexed: 11/08/2022] Open
Abstract
Stone toolmaking is a human motor skill which provides the earliest archeological evidence motor skill and social learning. Intentionally shaping a stone into a functional tool relies on the interaction of action observation and practice to support motor skill acquisition. The emergence of adaptive and efficient visuomotor processes during motor learning of such a novel motor skill requiring complex semantic understanding, like stone toolmaking, is not understood. Through the examination of eye movements and motor skill, the current study sought to evaluate the changes and relationship in perceptuomotor processes during motor learning and performance over 90 h of training. Participants' gaze and motor performance were assessed before, during and following training. Gaze patterns reveal a transition from initially high gaze variability during initial observation to lower gaze variability after training. Perceptual changes were strongly associated with motor performance improvements suggesting a coupling of perceptual and motor processes during motor learning.
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Affiliation(s)
| | - Nikhilesh Natraj
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
- Division of Neurology, UCSF Weill Institute for Neurosciences, San Francisco, CA, USA
| | - Nada Khresdish
- Anthropology Department, Emory University, Atlanta, GA, USA
| | - Justin Pargeter
- Anthropology Department, Emory University, Atlanta, GA, USA
- Department of Anthropology, New York University, New York, NY, USA
| | - Dietrich Stout
- Anthropology Department, Emory University, Atlanta, GA, USA
| | - Lewis A Wheaton
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA.
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Kimura A, Yokozawa T, Ozaki H. Clarifying the Biomechanical Concept of Coordination Through Comparison With Coordination in Motor Control. Front Sports Act Living 2021; 3:753062. [PMID: 34723181 PMCID: PMC8551718 DOI: 10.3389/fspor.2021.753062] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 09/16/2021] [Indexed: 12/02/2022] Open
Abstract
Coordination is a multidisciplinary concept in human movement science, particularly in the field of biomechanics and motor control. However, the term is not used synonymously by researchers and has substantially different meanings depending on the studies. Therefore, it is necessary to clarify the meaning of coordination to avoid confusion. The meaning of coordination in motor control from computational and ecological perspectives has been clarified, and the meanings differed between them. However, in biomechanics, each study has defined the meaning of the term and the meanings are diverse, and no study has attempted to bring together the diversity of the meanings of the term. Therefore, the purpose of this study is to provide a summary of the different meanings of coordination across the theoretical landscape and clarify the meaning of coordination in biomechanics. We showed that in biomechanics, coordination generally means the relation between elements that act toward the achievement of a motor task, which we call biomechanical coordination. We also showed that the term coordination used in computational and ecological perspectives has two different meanings, respectively. Each one had some similarities with biomechanical coordination. The findings of this study lead to an accurate understanding of the concept of coordination, which would help researchers formulate their empirical arguments for coordination in a more transparent manner. It would allow for accurate interpretation of data and theory development. By comprehensively providing multiple perspectives on coordination, this study intends to promote coordination studies in biomechanics.
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Affiliation(s)
- Arata Kimura
- Department of Sports Research, Japan Institute of Sports Sciences, Tokyo, Japan
| | - Toshiharu Yokozawa
- Department of Sports Research, Japan Institute of Sports Sciences, Tokyo, Japan
| | - Hiroki Ozaki
- Department of Sports Research, Japan Institute of Sports Sciences, Tokyo, Japan
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Ecology of musical performance as a model for evaluation and treatment of a musician with a playing related musculoskeletal disorder: A case report. J Hand Ther 2021; 34:330-337. [PMID: 34193381 DOI: 10.1016/j.jht.2021.04.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 04/25/2021] [Accepted: 04/30/2021] [Indexed: 02/03/2023]
Abstract
STUDY DESIGN Case report BACKGROUND: Musicians with playing related musculoskeletal disorders (PRMD) require complex decision making to interpret examination findings and develop a holistic treatment approach that considers the unique interaction with their instrument. The Ecology of Musical Performance (EMP) model is a novel comprehensive clinical model designed to provide guidance for musician-centered evaluation, goal setting, and intervention planning for musicians with PRMD. PURPOSE OF THE STUDY To describe the application of EMP in the evaluation and treatment of a pianist with PRMD. METHODS Clinical documentation and the patient's symptom logs provided data for this study. Special considerations unique to musicians in the initial evaluation as well as a timeline of interventions are presented to illustrate the application of the EMP model for a holistic approach to treatment. RESULTS AND DISCUSSION The pianist showed an increase in grip strength and self-reported hand function both in daily activities and in piano performance and training. Pain free practice tolerance increased and the patient successfully returned to participation in piano training and performance. CONCLUSION This case demonstrates how a treatment program can be customized to benefit musicians taking into consideration the complexity introduced by their relationship with music making as a primary meaningful occupation. EMP may support a person-centered approach to musicians with PRMD by aligning with the phenomenology of musical performance and facilitating collaborative goal setting and problem solving.
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