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Eilfort AM, Rasenack M, Zörner B, Curt A, Filli L. Evidence for reticulospinal plasticity underlying motor recovery in Brown-Séquard-plus Syndrome: a case report. Front Neurol 2024; 15:1335795. [PMID: 38895696 PMCID: PMC11183277 DOI: 10.3389/fneur.2024.1335795] [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: 11/09/2023] [Accepted: 05/10/2024] [Indexed: 06/21/2024] Open
Abstract
Brown-Séquard Syndrome (BSS) is a rare neurological condition caused by a unilateral spinal cord injury (SCI). Upon initial ipsilesional hemiplegia, patients with BSS typically show substantial functional recovery over time. Preclinical studies on experimental BSS demonstrated that spontaneous neuroplasticity in descending motor systems is a key mechanism promoting functional recovery. The reticulospinal (RS) system is one of the main descending motor systems showing a remarkably high ability for neuroplastic adaptations after incomplete SCI. In humans, little is known about the contribution of RS plasticity to functional restoration after SCI. Here, we investigated RS motor drive to different muscles in a subject with Brown-Séquard-plus Syndrome (BSPS) five months post-injury using the StartReact paradigm. RS drive was compared between ipsi- and contralesional muscles, and associated with measures of functional recovery. Additionally, corticospinal (CS) drive was investigated using transcranial magnetic stimulation (TMS) in a subset of muscles. The biceps brachii showed a substantial enhancement of RS drive on the ipsi- vs. contralesional side, whereas no signs of CS plasticity were found ipsilesionally. This finding implies that motor recovery of ipsilesional elbow flexion is primarily driven by the RS system. Results were inversed for the ipsilesional tibialis anterior, where RS drive was not augmented, but motor-evoked potentials recovered over six months post-injury, suggesting that CS plasticity contributed to improvements in ankle dorsiflexion. Our findings indicate that the role of RS and CS plasticity in motor recovery differs between muscles, with CS plasticity being essential for the restoration of distal extremity motor function, and RS plasticity being important for the functional recovery of proximal flexor muscles after SCI in humans.
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Affiliation(s)
- Antonia Maria Eilfort
- Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
- Department of Health Science and Technology, ETH Zurich, Zurich, Switzerland
| | - Maria Rasenack
- Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland
| | - Björn Zörner
- Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland
- Swiss Paraplegic Center and Swiss Paraplegic Research, Nottwil, Switzerland
| | - Armin Curt
- Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
| | - Linard Filli
- Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
- Swiss Center for Movement Analysis, Balgrist Campus AG, Zurich, Switzerland
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2
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Dutil C, De Pieri J, Sadler CM, Maslovat D, Chaput JP, Carlsen AN. Chronic short sleep duration lengthens reaction time, but the deficit is not associated with motor preparation. J Sleep Res 2024:e14231. [PMID: 38782723 DOI: 10.1111/jsr.14231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 03/27/2024] [Accepted: 04/22/2024] [Indexed: 05/25/2024]
Abstract
The purpose of this study was to investigate the association between chronic sleep duration and reaction time performance and motor preparation during a simple reaction time task with a startling acoustic stimulus in adults. This cross-sectional study included self-reported short sleepers (n = 25, ≤ 6 hr per night) and adequate sleepers (n = 25, ≥ 7.5 hr per night) who performed a simple reaction time task requiring a targeted ballistic wrist extension in response to either a control-tone (80 dB) or a startling acoustic stimulus (120 dB). Outcome measures included reaction times for each stimulus (overall and for each trial block), lapses, and proportion of startle responses. Chronic short sleepers slept on average 5.7 hr per night in the previous month, which was 2.8 hr per night less than the adequate sleepers. Results revealed an interaction between sleep duration group and stimulus type; the short sleepers had significantly slower control-tone reaction times compared with adequate sleepers, but there was no significant difference in reaction time between groups for the startling acoustic stimulus. Further investigation showed that chronic short sleepers had significantly slower control-tone reaction times after two blocks of trials lasting about 5 min, until the end of the task. Lapses were not significantly different between groups. Chronic short sleep duration was associated with poorer performance; however, these reaction time deficits cannot be attributed to motor preparation, as startling acoustic stimulus reaction times were not different between sleep duration groups. While time-on-task performance decrements were associated with chronic sleep duration, alertness was not. Sleeping less than the recommended sleep duration on a regular basis is associated with poorer cognitive performance, which becomes evident after 5 min.
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Affiliation(s)
- Caroline Dutil
- School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ottawa, Ontario, Canada
- Healthy Active Living and Obesity Research Group, Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada
| | - Julia De Pieri
- School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ottawa, Ontario, Canada
| | - Christin M Sadler
- School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ottawa, Ontario, Canada
- Healthy Active Living and Obesity Research Group, Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada
| | - Dana Maslovat
- School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ottawa, Ontario, Canada
| | - Jean-Philippe Chaput
- School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ottawa, Ontario, Canada
- Healthy Active Living and Obesity Research Group, Children's Hospital of Eastern Ontario Research Institute, Ottawa, Ontario, Canada
- School of Epidemiology and Public Health, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Anthony N Carlsen
- School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ottawa, Ontario, Canada
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Castellote JM, Kofler M, Mayr A. The benefit of knowledge: postural response modulation by foreknowledge of equilibrium perturbation in an upper limb task. Eur J Appl Physiol 2024; 124:975-991. [PMID: 37755580 PMCID: PMC10879248 DOI: 10.1007/s00421-023-05323-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 09/15/2023] [Indexed: 09/28/2023]
Abstract
For whole-body sway patterns, a compound motor response following an external stimulus may comprise reflexes, postural adjustments (anticipatory or compensatory), and voluntary muscular activity. Responses to equilibrium destabilization may depend on both motor set and a subject`s expectation of the disturbing stimulus. To disentangle these influences on lower limb responses, we studied a model in which subjects (n = 14) were suspended in the air, without foot support, and performed a fast unilateral wrist extension (WE) in response to a passive knee flexion (KF) delivered by a robot. To characterize the responses, electromyographic activity of rectus femoris and reactive leg torque was obtained bilaterally in a series of trials, with or without the requirement of WE (motor set), and/or beforehand information about the upcoming velocity of KF (subject`s expectation). Some fast-velocity trials resulted in StartReact responses, which were used to subclassify leg responses. When subjects were uninformed about the upcoming KF, large rectus femoris responses concurred with a postural reaction in conditions without motor task, and with both postural reaction and postural adjustment when WE was required. WE in response to a low-volume acoustic signal elicited no postural adjustments. When subjects were informed about KF velocity and had to perform WE, large rectus femoris responses corresponded to anticipatory postural adjustment rather than postural reaction. In conclusion, when subjects are suspended in the air and have to respond with WE, the prepared motor set includes anticipatory postural adjustments if KF velocity is known, and additional postural reactions if KF velocity is unknown.
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Affiliation(s)
- Juan M Castellote
- Radiology, Rehabilitation and Physiotherapy Department, Faculty of Medicine, Universidad Complutense, Madrid, Spain.
| | - Markus Kofler
- Department of Neurology, Hochzirl Hospital, Zirl, Austria
| | - Andreas Mayr
- Department of Neurology, Hochzirl Hospital, Zirl, Austria
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4
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Dietz V, Holliger NS, Christen A, Geissmann M, Filli L. Neural coordination of bilateral hand movements: evidence for an involvement of brainstem motor centres. J Physiol 2024; 602:397-412. [PMID: 38178603 DOI: 10.1113/jp285403] [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: 07/30/2023] [Accepted: 12/20/2023] [Indexed: 01/06/2024] Open
Abstract
Bilateral hand movements are assumed to be coordinated by a neural coupling mechanism. Neural coupling is experimentally reflected in complex electromyographic (EMG) responses in the forearm muscles of both sides to unilateral electrical arm nerve stimulation (ES). The aim of this study was to examine a potential involvement of the reticulospinal system in neural coupling by the application of loud acoustic stimuli (LAS) known to activate neurons of this system. LAS, ES and combined LAS/ES were applied to healthy subjects during visually guided bilateral hand flexion-extension movements. Muscle responses to the different stimuli were evaluated by electrophysiological recordings. Unilateral electrical ulnar nerve stimulation resulted in neural coupling responses in the forearm extensors (FE) of both sides. Interestingly, LAS evoked bilateral EMG responses that were similar in their configuration to those induced by ES. The presence of startles was associated with a shift of the onset and enhanced amplitude of LAS-induced coupling-like responses. Upon combined LAS/ES application, ES facilitated ipsilateral startles and coupling-like responses. Modulation of coupling-like responses by startles, the similarity of the responses to ES and LAS, and their interaction following combined stimulation suggests that both responses are mediated by the reticulospinal system. Our findings provide novel indirect evidence that the reticulospinal system is involved in the neural coupling of hand movements. This becomes clinically relevant in subjects with a damaged corticospinal system where a dominant reticulospinal system leads to involuntary limb coupling, referred to as associated movements. KEY POINTS: Automatic coordination of hand movements is assumed to be mediated by a neural coupling mechanism reflected by bilateral reflex responses in forearm muscles to unilateral electrical arm nerve stimulation (ES). Loud acoustic stimuli (LAS) were applied to assess a potential involvement of the reticulospinal system in the neural coupling mechanism. LAS evoked a bilateral reflex response in the forearm extensors that was similar to the neural coupling response to ES, and which could be separated from the acoustic startle response. Combined application of LAS and ES resulted in a facilitation of startle and coupling-like responses ipsilateral to ES, thus indicating an interaction of afferences from both stimuli. These novel findings provide indirect evidence that the reticulospinal system is a key motor structure for the coupling of bilateral hand movements.
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Affiliation(s)
- Volker Dietz
- Spinal Cord Injury Center, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
| | - Nicole Sarah Holliger
- Spinal Cord Injury Center, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
| | - Andrin Christen
- Spinal Cord Injury Center, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
| | - Marina Geissmann
- Swiss Center for Movement Analysis (SCMA), Balgrist Campus AG, Zurich, Switzerland
| | - Linard Filli
- Spinal Cord Injury Center, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
- Swiss Center for Movement Analysis (SCMA), Balgrist Campus AG, Zurich, Switzerland
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Heckman RL, Ludvig D, Perreault EJ. A motor plan is accessible for voluntary initiation and involuntary triggering at similar short latencies. Exp Brain Res 2023; 241:2395-2407. [PMID: 37634132 DOI: 10.1007/s00221-023-06666-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 07/06/2023] [Indexed: 08/29/2023]
Abstract
Movement goals are an essential component of motor planning, altering voluntary and involuntary motor actions. While there have been many studies of motor planning, it is unclear if motor goals influence voluntary and involuntary movements at similar latencies. The objectives of this study were to determine how long it takes to prepare a motor action and to compare this time for voluntary and involuntary movements. We hypothesized a prepared motor action would influence voluntarily and involuntarily initiated movements at the same latency. We trained subjects to reach with a forced reaction time paradigm and used a startling acoustic stimulus (SAS) to trigger involuntary initiation of the same reaches. The time available to prepare was controlled by varying when one of four reach targets was presented. Reach direction was used to evaluate accuracy. We quantified the time between target presentation and the cue or trigger for movement initiation. We found that reaches were accurately initiated when the target was presented 48 ms before the SAS and 162 ms before the cue to voluntarily initiate movement. While the SAS precisely controlled the latency of movement onset, voluntary reach onset was more variable. We, therefore, quantified the time between target presentation and movement onset and found no significant difference in the time required to plan reaches initiated voluntarily or involuntarily (∆ = 8 ms, p = 0.2). These results demonstrate that the time required to plan accurate reaches is similar regardless of if they are initiated voluntarily or triggered involuntarily. This finding may inform the understanding of neural pathways governing storage and access of motor plans.
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Affiliation(s)
- Rosalind L Heckman
- Department of Physical Therapy, Creighton University, Omaha, NE, 68178, USA.
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, 60208, USA.
- Shirley Ryan Ability Lab, Chicago, IL, 60611, USA.
| | - Daniel Ludvig
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, 60208, USA
- Shirley Ryan Ability Lab, Chicago, IL, 60611, USA
| | - Eric J Perreault
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, 60208, USA
- Shirley Ryan Ability Lab, Chicago, IL, 60611, USA
- Department of Physical Medicine and Rehabilitation, Northwestern University, Chicago, IL, 60611, USA
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6
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Nevanperä S, Hu N, Walker S, Avela J, Piirainen JM. Modulation of H-reflex and V-wave responses during dynamic balance perturbations. Exp Brain Res 2023; 241:1599-1610. [PMID: 37142781 DOI: 10.1007/s00221-023-06625-6] [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: 10/04/2022] [Accepted: 04/25/2023] [Indexed: 05/06/2023]
Abstract
Motoneuron excitability is possible to measure using H-reflex and V-wave responses. However, it is not known how the motor control is organized, how the H-reflex and V-wave responses modulate and how repeatable these are during dynamic balance perturbations. To assess the repeatability, 16 participants (8 men, 8 women) went through two, identical measurement sessions with ~ 48 h intervals, where maximal isometric plantar flexion (IMVC) and dynamic balance perturbations in horizontal, anterior-posterior direction were performed. Soleus muscle (SOL) neural modulation during balance perturbations were measured at 40, 70, 100 and 130 ms after ankle movement by using both H-reflex and V-wave methods. V-wave, which depicts the magnitude of efferent motoneuronal output (Bergmann et al. in JAMA 8:e77705, 2013), was significantly enhanced as early as 70 ms after the ankle movement. Both the ratio of M-wave-normalized V-wave (0.022-0.076, p < 0.001) and H-reflex (0.386-0.523, p < 0.001) increased significantly at the latency of 70 ms compared to the latency of 40 ms and remained at these levels at latter latencies. In addition, M-wave normalized V-wave/H-reflex ratio increased from 0.056 to 0.179 (p < 0.001). The repeatability of V-wave demonstrated moderate-to-substantial repeatability (ICC = 0.774-0.912) whereas the H-reflex was more variable showing fair-to-substantial repeatability (ICC = 0.581-0.855). As a conclusion, V-wave was enhanced already at 70 ms after the perturbation, which may indicate that increased activation of motoneurons occurred due to changes in descending drive. Since this is a short time-period for voluntary activity, some other, potentially subcortical responses might be involved for V-wave increment rather than voluntary drive. Our results addressed the usability and repeatability of V-wave method during dynamic conditions, which can be utilized in future studies.
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Affiliation(s)
- Samuli Nevanperä
- Sports Technology Program, Faculty of Sport and Health Sciences, University of Jyväskylä, Kidekuja 2, 88610, Vuokatti, Finland.
- NeuroMuscular Research Center, Faculty of Sport and Health Sciences, University of Jyväskylä, Rautpohjankatu 8, PL35, 40700, Jyväskylä, Finland.
| | - Nijia Hu
- NeuroMuscular Research Center, Faculty of Sport and Health Sciences, University of Jyväskylä, Rautpohjankatu 8, PL35, 40700, Jyväskylä, Finland
| | - Simon Walker
- NeuroMuscular Research Center, Faculty of Sport and Health Sciences, University of Jyväskylä, Rautpohjankatu 8, PL35, 40700, Jyväskylä, Finland
| | - Janne Avela
- NeuroMuscular Research Center, Faculty of Sport and Health Sciences, University of Jyväskylä, Rautpohjankatu 8, PL35, 40700, Jyväskylä, Finland
| | - Jarmo M Piirainen
- Sports Technology Program, Faculty of Sport and Health Sciences, University of Jyväskylä, Kidekuja 2, 88610, Vuokatti, Finland
- NeuroMuscular Research Center, Faculty of Sport and Health Sciences, University of Jyväskylä, Rautpohjankatu 8, PL35, 40700, Jyväskylä, Finland
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7
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Maslovat D, Santangelo CM, Carlsen AN. Startle-triggered responses indicate reticulospinal drive is larger for voluntary shoulder versus finger movements. Sci Rep 2023; 13:6532. [PMID: 37085607 PMCID: PMC10121700 DOI: 10.1038/s41598-023-33493-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 04/13/2023] [Indexed: 04/23/2023] Open
Abstract
Recent primate studies have implicated a substantial role of reticulospinal pathways in the production of various voluntary movements. A novel way to assess the relative reticulospinal contributions in humans is through the use of a "StartReact" paradigm where a startling acoustic stimulus (SAS) is presented during a simple reaction time (RT) task. The StartReact response is characterized by short-latency triggering of a prepared response, which is attributed to increased reticulospinal drive associated with startle reflex activation. The current study used a StartReact protocol to examine differences in reticulospinal contributions between proximal and distal effectors by examining EMG onset latencies in lateral deltoid and first dorsal interosseous during bilateral shoulder or finger abduction. The magnitude of the StartReact effect, and thus relative reticulospinal drive, was quantified as the difference in RT between startle trials in which startle-reflex related EMG activation in the sternocleidomastoid (SCM) was present (SCM +) versus absent (SCM -). A significantly larger StartReact effect was observed for bilateral shoulder abduction versus bimanual finger abduction and a higher incidence of SCM + trials occurred in the proximal task. Additionally, both startle reflex and response-related EMG measures were larger on SCM + trials for the shoulder versus finger task. These results provide compelling novel evidence for increased reticulospinal activation in bilateral proximal upper-limb movements.
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Affiliation(s)
- Dana Maslovat
- School of Human Kinetics, University of Ottawa, 125 University Private, Ottawa, ON, K1N 6N5, Canada
| | - Cassandra M Santangelo
- School of Human Kinetics, University of Ottawa, 125 University Private, Ottawa, ON, K1N 6N5, Canada
| | - Anthony N Carlsen
- School of Human Kinetics, University of Ottawa, 125 University Private, Ottawa, ON, K1N 6N5, Canada.
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Germann M, Maffitt NJ, Poll A, Raditya M, Ting JSK, Baker SN. Pairing Transcranial Magnetic Stimulation and Loud Sounds Produces Plastic Changes in Motor Output. J Neurosci 2023; 43:2469-2481. [PMID: 36859307 PMCID: PMC10082460 DOI: 10.1523/jneurosci.0228-21.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 11/29/2022] [Accepted: 12/09/2022] [Indexed: 03/03/2023] Open
Abstract
Most current methods for neuromodulation target the cortex. Approaches for inducing plasticity in subcortical motor pathways, such as the reticulospinal tract, could help to boost recovery after damage (e.g., stroke). In this study, we paired loud acoustic stimulation (LAS) with transcranial magnetic stimulation (TMS) over the motor cortex in male and female healthy humans. LAS activates the reticular formation; TMS activates descending systems, including corticoreticular fibers. Two hundred paired stimuli were used, with 50 ms interstimulus interval at which LAS suppresses TMS responses. Before and after stimulus pairing, responses in the contralateral biceps muscle to TMS alone were measured. Ten, 20, and 30 min after stimulus pairing ended, TMS responses were enhanced, indicating the induction of LTP. No long-term changes were seen in control experiments which used 200 unpaired TMS or LAS, indicating the importance of associative stimulation. Following paired stimulation, no changes were seen in responses to direct corticospinal stimulation at the level of the medulla, or in the extent of reaction time shortening by a loud sound (StartReact effect), suggesting that plasticity did not occur in corticospinal or reticulospinal synapses. Direct measurements in female monkeys undergoing a similar paired protocol revealed no enhancement of corticospinal volleys after paired stimulation, suggesting no changes occurred in intracortical connections. The most likely substrate for the plastic changes, consistent with all our measurements, is an increase in the efficacy of corticoreticular connections. This new protocol may find utility, as it seems to target different motor circuits compared with other available paradigms.SIGNIFICANCE STATEMENT Induction of plasticity by neurostimulation protocols may be promising to enhance functional recovery after damage such as following stroke, but current protocols mainly target cortical circuits. In this study, we developed a novel paradigm which may generate long-term changes in connections between cortex and brainstem. This could provide an additional tool to modulate and improve recovery.
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Affiliation(s)
- Maria Germann
- Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, United Kingdom
| | - Natalie J Maffitt
- Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, United Kingdom
| | - Annie Poll
- Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, United Kingdom
| | - Marco Raditya
- Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, United Kingdom
| | - Jason S K Ting
- Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, United Kingdom
| | - Stuart N Baker
- Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, United Kingdom
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9
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Zadeh AK, Videnovic A, MacKinnon CD, Alibiglou L. Startle-induced rapid release of a gait initiation sequence in Parkinson's disease with freezing of gait. Clin Neurophysiol 2023; 146:97-108. [PMID: 36608531 DOI: 10.1016/j.clinph.2022.12.005] [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: 05/04/2022] [Revised: 11/29/2022] [Accepted: 12/11/2022] [Indexed: 12/24/2022]
Abstract
OBJECTIVE Freezing of gait (FOG) in Parkinson's disease (PD) is characterized by the inability to initiate stepping, despite the intention to do so. This study used a startling acoustic stimulus paradigm to examine if the capacity to select, prepare and initiate gait under simple and choice reaction time conditions are impaired in people with PD and FOG. METHODS Thirty individuals (10 PD with FOG, 10 PD without FOG, and 10 controls) performed an instructed-delay gait initiation task under simple and choice reaction time conditions. In a subset of trials, a startle stimulus (124 dB) was presented 500 ms before the time of the imperative go-cue. Anticipatory postural adjustments preceding and accompanying gait initiation were quantified. RESULTS The presentation of a startling acoustic stimulus resulted in the rapid initiation of an anticipatory postural adjustment sequence during both the simple and choice reaction time tasks in all groups. CONCLUSIONS The neural capacity to prepare the spatial and temporal components of gait initiation remains intact in PD individuals with and without FOG. SIGNIFICANCE The retained capacity to prepare anticipatory postural adjustments in advance may explain why external sensory cues are effective in the facilitation of gait initiation in people with PD with FOG.
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Affiliation(s)
- Ali K Zadeh
- Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Aleksandar Videnovic
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Colum D MacKinnon
- Department of Neurology, University of Minnesota, Minneapolis, MN, USA; Department of Physical Therapy and Human Movement Sciences, Northwestern University, Chicago, IL, USA
| | - Laila Alibiglou
- Department of Neuroscience, School of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran; Department of Physical Therapy and Human Movement Sciences, Northwestern University, Chicago, IL, USA.
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10
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Charalambous CC, Hadjipapas A. Is there frequency-specificity in the motor control of walking? The putative differential role of alpha and beta oscillations. Front Syst Neurosci 2022; 16:922841. [PMID: 36387306 PMCID: PMC9650482 DOI: 10.3389/fnsys.2022.922841] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 10/14/2022] [Indexed: 11/04/2023] Open
Abstract
Alpha and beta oscillations have been assessed thoroughly during walking due to their potential role as proxies of the corticoreticulospinal tract (CReST) and corticospinal tract (CST), respectively. Given that damage to a descending tract after stroke can cause walking deficits, detailed knowledge of how these oscillations mechanistically contribute to walking could be utilized in strategies for post-stroke locomotor recovery. In this review, the goal was to summarize, synthesize, and discuss the existing evidence on the potential differential role of these oscillations on the motor descending drive, the effect of transcranial alternate current stimulation (tACS) on neurotypical and post-stroke walking, and to discuss remaining gaps in knowledge, future directions, and methodological considerations. Electrophysiological studies of corticomuscular, intermuscular, and intramuscular coherence during walking clearly demonstrate that beta oscillations are predominantly present in the dorsiflexors during the swing phase and may be absent post-stroke. The role of alpha oscillations, however, has not been pinpointed as clearly. We concluded that both animal and human studies should focus on the electrophysiological characterization of alpha oscillations and their potential role to the CReST. Another approach in elucidating the role of these oscillations is to modulate them and then quantify the impact on walking behavior. This is possible through tACS, whose beneficial effect on walking behavior (including boosting of beta oscillations in intramuscular coherence) has been recently demonstrated in both neurotypical adults and stroke patients. However, these studies still do not allow for specific roles of alpha and beta oscillations to be delineated because the tACS frequency used was much lower (i.e., individualized calculated gait frequency was used). Thus, we identify a main gap in the literature, which is tACS studies actually stimulating at alpha and beta frequencies during walking. Overall, we conclude that for beta oscillations there is a clear connection to descending drive in the corticospinal tract. The precise relationship between alpha oscillations and CReST remains elusive due to the gaps in the literature identified here. However, better understanding the role of alpha (and beta) oscillations in the motor control of walking can be used to progress and develop rehabilitation strategies for promoting locomotor recovery.
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Affiliation(s)
- Charalambos C. Charalambous
- Department of Basic and Clinical Sciences, Medical School, University of Nicosia, Nicosia, Cyprus
- Center for Neuroscience and Integrative Brain Research (CENIBRE), Medical School, University of Nicosia, Nicosia, Cyprus
| | - Avgis Hadjipapas
- Department of Basic and Clinical Sciences, Medical School, University of Nicosia, Nicosia, Cyprus
- Center for Neuroscience and Integrative Brain Research (CENIBRE), Medical School, University of Nicosia, Nicosia, Cyprus
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11
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van der Veen S, Caviness JN, Dreissen YE, Ganos C, Ibrahim A, Koelman JH, Stefani A, Tijssen MA. Myoclonus and other jerky movement disorders. Clin Neurophysiol Pract 2022; 7:285-316. [PMID: 36324989 PMCID: PMC9619152 DOI: 10.1016/j.cnp.2022.09.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 08/29/2022] [Accepted: 09/11/2022] [Indexed: 11/27/2022] Open
Abstract
Myoclonus and other jerky movements form a large heterogeneous group of disorders. Clinical neurophysiology studies can have an important contribution to support diagnosis but also to gain insight in the pathophysiology of different kind of jerks. This review focuses on myoclonus, tics, startle disorders, restless legs syndrome, and periodic leg movements during sleep. Myoclonus is defined as brief, shock-like movements, and subtypes can be classified based the anatomical origin. Both the clinical phenotype and the neurophysiological tests support this classification: cortical, cortical-subcortical, subcortical/non-segmental, segmental, peripheral, and functional jerks. The most important techniques used are polymyography and the combination of electromyography-electroencephalography focused on jerk-locked back-averaging, cortico-muscular coherence, and the Bereitschaftspotential. Clinically, the differential diagnosis of myoclonus includes tics, and this diagnosis is mainly based on the history with premonitory urges and the ability to suppress the tic. Electrophysiological tests are mainly applied in a research setting and include the Bereitschaftspotential, local field potentials, transcranial magnetic stimulation, and pre-pulse inhibition. Jerks due to a startling stimulus form the group of startle syndromes. This group includes disorders with an exaggerated startle reflex, such as hyperekplexia and stiff person syndrome, but also neuropsychiatric and stimulus-induced disorders. For these disorders polymyography combined with a startling stimulus can be useful to determine the pattern of muscle activation and thus the diagnosis. Assessment of symptoms in restless legs syndrome and periodic leg movements during sleep can be performed with different validated scoring criteria with the help of electromyography.
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Affiliation(s)
- Sterre van der Veen
- Department of Neurology, University of Groningen, University Medical Centre Groningen (UMCG), Groningen, The Netherlands,Expertise Centre Movement Disorders Groningen, University Medical Centre Groningen (UMCG), Groningen, The Netherlands
| | - John N. Caviness
- Department of Neurology, Mayo Clinic Arizona, Movement Neurophysiology Laboratory, Scottsdale, AZ, USA
| | - Yasmine E.M. Dreissen
- Department of Neurosurgery, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Christos Ganos
- Movement Disorders and Neuromodulation Unit, Department of Neurology, Charité University Medicine Berlin, Berlin, Germany
| | - Abubaker Ibrahim
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Johannes H.T.M. Koelman
- Department of Neurology and Clinical Neurophysiology, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Ambra Stefani
- Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
| | - Marina A.J. Tijssen
- Department of Neurology, University of Groningen, University Medical Centre Groningen (UMCG), Groningen, The Netherlands,Expertise Centre Movement Disorders Groningen, University Medical Centre Groningen (UMCG), Groningen, The Netherlands,Corresponding author at: Department of Neurology, University of Groningen, University Medical Centre Groningen (UMCG), PO Box 30.001, 9700 RB Groningen, The Netherlands.
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12
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Different equestrian sports horses’ reactivity to startle. J Vet Behav 2022. [DOI: 10.1016/j.jveb.2022.07.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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13
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Godøy RI. Thinking rhythm objects. Front Psychol 2022; 13:906479. [PMID: 35910948 PMCID: PMC9335008 DOI: 10.3389/fpsyg.2022.906479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 06/30/2022] [Indexed: 12/02/2022] Open
Abstract
The focus of this mini-review is on rhythm objects, defined as strongly coherent chunks of combined sound and body motion in music, typically in the duration range of a few seconds, as may for instance be found in a fragment of dance music, in an energetic drum fill, in a flute ornament, or in a cascade of sounds of a rapid harp glissando. Although there has been much research on rhythm in continuous musical sound and its links with behavior, including the neurocognitive aspects of periodicity, synchrony, and entrainment, there has been much less focus on the generation and perception of singular coherent rhythm objects. This mini-review aims to enhance our understanding of such rhythm objects by pointing to relevant literature on coherence-enhancing elements such as coarticulation, i.e., the fusion of motion events into more extended rhythm objects, and intermittent motor control, i.e., the discontinuous, instant-by-instant control and triggering of rhythm objects.
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Affiliation(s)
- Rolf Inge Godøy
- Department of Musicology, University of Oslo, Oslo, Norway
- RITMO Centre for Interdisciplinary Studies in Rhythm, Time and Motion, University of Oslo, Oslo, Norway
- *Correspondence: Rolf Inge Godøy,
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14
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Cleland BT, Madhavan S. Motor overflow in the lower limb after stroke: insights into mechanisms. Eur J Neurosci 2022; 56:4455-4468. [PMID: 35775788 PMCID: PMC9380181 DOI: 10.1111/ejn.15753] [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: 01/19/2022] [Revised: 06/06/2022] [Accepted: 06/21/2022] [Indexed: 11/29/2022]
Abstract
Motor overflow (involuntary muscle activation) is common after stroke, particularly in the non-paretic upper limb. Two potential cortical mechanisms are: 1) the contralesional hemisphere controls both limbs, and 2) inhibition from the ipsilesional to the contralesional hemisphere is diminished. Few studies have differentiated between these hypotheses or investigated motor overflow in the lower limb after stroke. To investigate these potential mechanisms, individuals with chronic stroke performed unilateral isometric and dynamic dorsiflexion. Motor overflow was quantified in the contralateral, resting (non-target) ankle. Transcranial magnetic stimulation was applied, and responses were measured in both legs. Relations between motor overflow, excitability of ipsilateral motor pathways, and interhemispheric inhibition were assessed. Non-target muscle activity (motor overflow) was greater during isometric and dynamic conditions than rest in both legs (p≤0.001) and was higher in the non-paretic than the paretic leg (p=0.03). Some participants (25%) had motor overflow >4SD above the group mean in the non-paretic leg. Greater motor overflow in the non-paretic leg was associated with lesser inhibition from the ipsilesional to the contralesional hemisphere (p=0.04). In both legs, non-target TMS responses were greater during the isometric and dynamic than the rest condition (p≤0.01), but not when normalized to background muscle activity. Overall, motor overflow occurred in both legs after stroke, suggesting a common bilateral mechanism. Our correlational results suggest that alterations in interhemispheric inhibition may contribute to motor overflow. Furthermore, the lack of differences in non-target MEPs between rest, isometric, and dynamic conditions, suggests that subcortical and/or spinal pathways may contribute to motor overflow.
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Affiliation(s)
- Brice T Cleland
- Brain Plasticity Lab, Department of Physical Therapy, College of Applied Health Sciences University of Illinois at Chicago, Chicago, IL, USA
| | - Sangeetha Madhavan
- Brain Plasticity Lab, Department of Physical Therapy, College of Applied Health Sciences University of Illinois at Chicago, Chicago, IL, USA
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15
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Sehlström M, Ljungberg JK, Claeson AS, Nyström MBT. The relation of neuroticism to physiological and behavioral stress responses induced by auditory startle. Brain Behav 2022; 12:e2554. [PMID: 35403836 PMCID: PMC9120885 DOI: 10.1002/brb3.2554] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 01/25/2022] [Accepted: 02/26/2022] [Indexed: 11/06/2022] Open
Abstract
INTRODUCTION The negative cognitive effects of the startle response are not yet fully understood. Ecological observations in the aviation field indicate risk for severe outcomes in complex or pressured situations, while sparse previous research suggests milder negative effects on simple cognitive tasks. Neuroticism is proposed as a factor related to the level of negative effects following startle. METHODS This study examined the effects of startle on performance in a choice reaction time task and analyzed relations between performance, neuroticism, and physiological stress. RESULTS Our results indicate that reaction time directly following startle was not affected, but reaction time in subsequent trials was significantly slower. Neuroticism and physiological stress were both unrelated to this performance effect. DISCUSSION We argue that higher complexity/demand tasks are necessary to complement the research on base cognitive functioning in relation to startle. If neuroticism is related to startle effects, this is more likely to be found in these higher demand situations.
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Affiliation(s)
| | - Jessica K Ljungberg
- Engineering Psychology, Department of Health, Learning and Technology, Luleå University of Technology, Luleå, Sweden
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16
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Sadler CM, Maslovat D, Cressman EK, Dutil C, Carlsen AN. Response Preparation of a Secondary Reaction Time Task is Influenced by Movement Phase within a Continuous Visuomotor Tracking Task. Eur J Neurosci 2022; 56:3645-3659. [PMID: 35445463 DOI: 10.1111/ejn.15675] [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: 09/04/2021] [Revised: 03/24/2022] [Accepted: 04/18/2022] [Indexed: 11/29/2022]
Abstract
The simultaneous performance of two motor tasks is challenging. Currently, it is unclear how response preparation of a secondary task is impacted by the performance of a continuous primary task. The purpose of the present experiment was to investigate whether the position of the limb performing the primary cyclical tracking task impacts response preparation of a secondary reaction time task. Participants (n=20) performed a continuous tracking task with their left hand that involved cyclical and targeted wrist flexion and extension. Occasionally, a probe reaction time task requiring isometric wrist extension was performed with the right hand in response to an auditory stimulus (80 dB or 120 dB) that was triggered when the left hand passed through one of ten locations identified within the movement cycle. On separate trials, transcranial magnetic stimulation was applied over the left primary motor cortex and triggered at the same 10 stimulus locations to assess corticospinal excitability associated with the probe reaction time task. Results revealed that probe reaction times were significantly longer and motor evoked potential amplitudes were significantly larger when the left hand was in the middle of a movement cycle compared to an endpoint, suggesting that response preparation of a secondary probe reaction time task was modulated by the phase of movement within the continuous primary task. These results indicate that primary motor task requirements can impact preparation of a secondary task, reinforcing the importance of considering primary task characteristics in dual-task experimental design.
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17
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Godøy RI. Constraint-Based Sound-Motion Objects in Music Performance. Front Psychol 2022; 12:732729. [PMID: 34992562 PMCID: PMC8725797 DOI: 10.3389/fpsyg.2021.732729] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 11/23/2021] [Indexed: 01/09/2023] Open
Abstract
The aim of this paper is to present principles of constraint-based sound-motion objects in music performance. Sound-motion objects are multimodal fragments of combined sound and sound-producing body motion, usually in the duration range of just a few seconds, and conceived, produced, and perceived as intrinsically coherent units. Sound-motion objects have a privileged role as building blocks in music because of their duration, coherence, and salient features and emerge from combined instrumental, biomechanical, and motor control constraints at work in performance. Exploring these constraints and the crucial role of the sound-motion objects can enhance our understanding of generative processes in music and have practical applications in performance, improvisation, and composition.
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Affiliation(s)
- Rolf Inge Godøy
- Department of Musicology, University of Oslo, Oslo, Norway.,RITMO Centre for Interdisciplinary Studies in Rhythm, Time and Motion, University of Oslo, Oslo, Norway
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18
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Response triggering by an acoustic stimulus increases with stimulus intensity and is best predicted by startle reflex activation. Sci Rep 2021; 11:23612. [PMID: 34880317 PMCID: PMC8655082 DOI: 10.1038/s41598-021-02825-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 11/15/2021] [Indexed: 11/17/2022] Open
Abstract
In a simple reaction time task, the presentation of a startling acoustic stimulus has been shown to trigger the prepared response at short latency, known as the StartReact effect. However, it is unclear under what conditions it can be assumed that the loud stimulus results in response triggering. The purpose of the present study was to examine how auditory stimulus intensity and preparation level affect the probability of involuntary response triggering and the incidence of activation in the startle reflex indicator of sternocleidomastoid (SCM). In two reaction time experiments, participants were presented with an irrelevant auditory stimulus of varying intensities at various time points prior to the visual go-signal. Responses were independently categorized as responding to either the auditory or visual stimulus and those with or without SCM activation (i.e., SCM+/−). Both the incidence of response triggering and proportion of SCM+ trials increased with stimulus intensity and presentation closer to the go-signal. Data also showed that participants reacted to the auditory stimulus at a much higher rate on trials where the auditory stimulus elicited SCM activity versus those that did not, and a logistic regression analysis confirmed that SCM activation is a reliable predictor of response triggering for all conditions.
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19
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Cesanelli L, Cesaretti G, Ylaitė B, Iovane A, Bianco A, Messina G. Occlusal Splints and Exercise Performance: A Systematic Review of Current Evidence. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph181910338. [PMID: 34639640 PMCID: PMC8507675 DOI: 10.3390/ijerph181910338] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 09/27/2021] [Accepted: 09/28/2021] [Indexed: 12/27/2022]
Abstract
The role of the dento-mandibular apparatus and, in particular, occlusion and jaw position, received increased attention during last years. In the present study, we aimed to systematically review, on the light of the new potential insights, the published literature covering the occlusal splint (OS) applications, and its impact on exercise performance. A structured search was carried out including MEDLINE®/PubMed and Scopus databases with additional integration from external sources, between March and June 2021. To meet the inclusion criteria, studies published in the English language, involving humans in vivo, published from 2000 to 2021 and that investigated the role of occlusal splints on athletes' performance were selected. Starting from the 587 identified records, 17 items were finally included for the review. Four main aspects were considered and analyzed: (1) occlusal splint characteristics and occlusion experimental conditions, (2) jump performance, (3) maximal and explosive strength, and (4) exercise technique and biomechanics. The results of the systematic literature analysis depicted a wide heterogenicity in the experimental conditions and suggested the application of the OS as a way to improve athletes' or individuals' oral health, and as a potential tool to optimize marginal aspects of exercise performance.
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Affiliation(s)
- Leonardo Cesanelli
- Sport and Exercise Sciences Research Unit, Department of Psychological, Pedagogical and Educational Sciences, University of Palermo, 90128 Palermo, Italy; (L.C.); (A.I.); (A.B.)
| | - Gianfranco Cesaretti
- Ariminum Research & Dental Education Center, ARDEC Academy, 47923 Rimini, Italy;
| | - Berta Ylaitė
- Faculty of Sport Biomedicine, Institute of Sport Science and Innovations, Lithuanian Sports University, 44221 Kaunas, Lithuania;
| | - Angelo Iovane
- Sport and Exercise Sciences Research Unit, Department of Psychological, Pedagogical and Educational Sciences, University of Palermo, 90128 Palermo, Italy; (L.C.); (A.I.); (A.B.)
| | - Antonino Bianco
- Sport and Exercise Sciences Research Unit, Department of Psychological, Pedagogical and Educational Sciences, University of Palermo, 90128 Palermo, Italy; (L.C.); (A.I.); (A.B.)
| | - Giuseppe Messina
- Sport and Exercise Sciences Research Unit, Department of Psychological, Pedagogical and Educational Sciences, University of Palermo, 90128 Palermo, Italy; (L.C.); (A.I.); (A.B.)
- Correspondence:
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20
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Cleland BT, Madhavan S. Ipsilateral motor pathways to the lower limb after stroke: Insights and opportunities. J Neurosci Res 2021; 99:1565-1578. [PMID: 33665910 DOI: 10.1002/jnr.24822] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 02/17/2021] [Indexed: 01/04/2023]
Abstract
Stroke-related damage to the crossed lateral corticospinal tract causes motor deficits in the contralateral (paretic) limb. To restore functional movement in the paretic limb, the nervous system may increase its reliance on ipsilaterally descending motor pathways, including the uncrossed lateral corticospinal tract, the reticulospinal tract, the rubrospinal tract, and the vestibulospinal tract. Our knowledge about the role of these pathways for upper limb motor recovery is incomplete, and even less is known about the role of these pathways for lower limb motor recovery. Understanding the role of ipsilateral motor pathways to paretic lower limb movement and recovery after stroke may help improve our rehabilitative efforts and provide alternate solutions to address stroke-related impairments. These advances are important because walking and mobility impairments are major contributors to long-term disability after stroke, and improving walking is a high priority for individuals with stroke. This perspective highlights evidence regarding the contributions of ipsilateral motor pathways from the contralesional hemisphere and spinal interneuronal pathways for paretic lower limb movement and recovery. This perspective also identifies opportunities for future research to expand our knowledge about ipsilateral motor pathways and provides insights into how this information may be used to guide rehabilitation.
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Affiliation(s)
- Brice T Cleland
- Brain Plasticity Lab, Department of Physical Therapy, College of Applied Health Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Sangeetha Madhavan
- Brain Plasticity Lab, Department of Physical Therapy, College of Applied Health Sciences, University of Illinois at Chicago, Chicago, IL, USA
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21
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Versace V, Campostrini S, Sebastianelli L, Saltuari L, Valls-Solé J, Kofler M. Prepulse inhibition vs cognitive modulation of the hand-blink reflex. Sci Rep 2021; 11:4618. [PMID: 33633320 PMCID: PMC7907410 DOI: 10.1038/s41598-021-84241-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 02/11/2021] [Indexed: 12/01/2022] Open
Abstract
The excitability of brainstem circuitries mediating defensive blinking in response to abrupt sensory inputs is continuously modulated by cortical areas, e.g., the hand-blink reflex (HBR), elicited by intense electrical median nerve stimulation, is enhanced when the stimulated hand is close to the face, with the behavioural purpose to optimize self-protection from increased threat. Here we investigated whether such cortically mediated HBR facilitation can be influenced by prepulse inhibition (PPI), which is known to occur entirely at the subcortical level. Twenty healthy volunteers underwent HBR recordings in five experimental conditions. In conditions 1 and 2, the stimulated hand was held either near (1) or far (2) from the face, respectively. In conditions 3 and 4, stimulation of the hand near the face was preceded by a peri-liminal prepulse to the index finger of the contralateral hand held either near (3) or far from the face (4). In condition 5, participants self-triggered the stimulus eliciting the HBR. We observed a reproducible HBR in 14 out of 20 participants and measured onset latency and area of the HBR in orbicularis oculi muscles bilaterally. HBR area decreased and latency increased in condition 2 relative to condition 1; HBR area decreased and latency increased markedly in condition 3, and somewhat less in condition 4, relative to conditions 1 and 2; self-stimulation (condition 5) also suppressed HBRs, but less than prepulses. These findings indicate that PPI of the HBR is more robust than the cognitive modulation exerted by top-down cortical projections. Possibly, an attentional shift to a prepulse may serve to reduce blinking in response to perturbation when it is convenient, in a given situation, not to interrupt ongoing visual processing.
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Affiliation(s)
- Viviana Versace
- Department of Neurorehabilitation, Hospital of Vipiteno-Sterzing (SABES-ASDAA), Margarethenstr. 24, 39049, Vipiteno-Sterzing, BZ, Italy.
| | - Stefania Campostrini
- Department of Neurorehabilitation, Hospital of Vipiteno-Sterzing (SABES-ASDAA), Margarethenstr. 24, 39049, Vipiteno-Sterzing, BZ, Italy
| | - Luca Sebastianelli
- Department of Neurorehabilitation, Hospital of Vipiteno-Sterzing (SABES-ASDAA), Margarethenstr. 24, 39049, Vipiteno-Sterzing, BZ, Italy
| | - Leopold Saltuari
- Department of Neurorehabilitation, Hospital of Vipiteno-Sterzing (SABES-ASDAA), Margarethenstr. 24, 39049, Vipiteno-Sterzing, BZ, Italy
| | - Josep Valls-Solé
- IDIBAPS (Institut d'Investigació August Pi i Sunyer), Facultat de Medicina, University of Barcelona, Barcelona, Spain
| | - Markus Kofler
- Department of Neurology, Hochzirl Hospital, Zirl, Austria
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22
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Maslovat D, Teku F, Smith V, Drummond NM, Carlsen AN. Bimanual but not unimanual finger movements are triggered by a startling acoustic stimulus: evidence for increased reticulospinal drive for bimanual responses. J Neurophysiol 2020; 124:1832-1838. [PMID: 33026906 DOI: 10.1152/jn.00309.2020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The relative contributions of reticulospinal versus corticospinal pathways for movement production are thought to be dependent on the type of response involved. For example, unilateral distal movements involving the hand and finger have been thought to be primarily driven by corticospinal output, whereas bilateral responses are considered to have greater reticulospinal drive. The current study investigated whether a difference in the relative contribution of reticulospinal drive to a bimanual versus unimanual finger movement could be assessed using a StartReact protocol. The StartReact effect refers to the early and involuntary initiation of a prepared movement when a startle reflex is elicited. A decreased response latency on loud stimulus trials where a startle reflex is observed in sternocleidomastoid (SCM+ trials) confirms the StartReact effect, which is attributed to increased reticulospinal drive associated with engagement of the startle reflex circuitry. It was predicted that a StartReact effect would be absent for the predominantly corticospinal-mediated unimanual finger movement but present for the bimanual finger movement due to stronger reticulospinal drive. Results supported both predictions as reaction time was statistically equivalent for SCM+ and SCM- trials during unimanual finger movements but significantly shorter for SCM+ trials during bimanual finger movements. These results were taken as strong and novel evidence for increased reticulospinal output for bimanual finger movements.NEW & NOTEWORTHY The relative contributions of reticulospinal and corticospinal pathways to movement initiation are relatively unknown but appear to depend on the involved musculature. Here, we show that unimanual finger movements, which are predominantly initiated via corticospinal pathways, are not triggered at short latency by a startling acoustic stimulus (SAS), while bimanual finger movements are triggered by the SAS. This distinction is attributed to increased reticulospinal drive for bilateral responses.
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Affiliation(s)
- Dana Maslovat
- School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - Faven Teku
- School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - Victoria Smith
- School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - Neil M Drummond
- Krembil Research Institute, University Health Network, Toronto, Canada
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23
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Schultz BG, Brown RM, Kotz SA. Dynamic acoustic salience evokes motor responses. Cortex 2020; 134:320-332. [PMID: 33340879 DOI: 10.1016/j.cortex.2020.10.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 06/25/2020] [Accepted: 10/08/2020] [Indexed: 11/28/2022]
Abstract
Audio-motor integration is currently viewed as a predictive process in which the brain simulates upcoming sounds based on voluntary actions. This perspective does not consider how our auditory environment may trigger involuntary action in the absence of prediction. We address this issue by examining the relationship between acoustic salience and involuntary motor responses. We investigate how acoustic features in music contribute to the perception of salience, and whether those features trigger involuntary peripheral motor responses. Participants with little-to-no musical training listened to musical excerpts once while remaining still during the recording of their muscle activity with surface electromyography (sEMG), and again while they continuously rated perceived salience within the music using a slider. We show cross-correlations between 1) salience ratings and acoustic features, 2) acoustic features and spontaneous muscle activity, and 3) salience ratings and spontaneous muscle activity. Amplitude, intensity, and spectral centroid were perceived as the most salient features in music, and fluctuations in these features evoked involuntary peripheral muscle responses. Our results suggest an involuntary mechanism for audio-motor integration, which may rely on brainstem-spinal or brainstem-cerebellar-spinal pathways. Based on these results, we argue that a new framework is needed to explain the full range of human sensorimotor capabilities. This goal can be achieved by considering how predictive and reactive audio-motor integration mechanisms could operate independently or interactively to optimize human behavior.
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Affiliation(s)
- Benjamin G Schultz
- Basic & Applied NeuroDynamics Laboratory, Faculty of Psychology & Neuroscience, Department of Neuropsychology & Psychopharmacology, Maastricht University, the Netherlands
| | - Rachel M Brown
- Basic & Applied NeuroDynamics Laboratory, Faculty of Psychology & Neuroscience, Department of Neuropsychology & Psychopharmacology, Maastricht University, the Netherlands
| | - Sonja A Kotz
- Basic & Applied NeuroDynamics Laboratory, Faculty of Psychology & Neuroscience, Department of Neuropsychology & Psychopharmacology, Maastricht University, the Netherlands.
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24
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Scott M, Chiu C. Temporal binding and agency under startle. Exp Brain Res 2020; 239:289-300. [PMID: 33165671 DOI: 10.1007/s00221-020-05972-y] [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: 02/13/2020] [Accepted: 10/24/2020] [Indexed: 11/30/2022]
Abstract
Forward models are a component of the motor system that predicts the sensory consequences of our actions. These models play several key roles in motor control and are hypothesized to underlie (among other things) the two phenomena under investigation in this experiment: The feeling of agency that we have over self-initiated actions (as opposed to reflexes), and "temporal binding", in which self-caused sensations are judged to have occurred earlier in time than they actually did. This experiment probes the connection between forward models and both of these phenomena using the "Startle" paradigm. In the Startle paradigm, a startlingly loud sound causes people to initiate a prepared action at a very short latency. It is hypothesized that the latency of a startle-initiated action is so short that normal cortical operations (including forward models) are circumvented. This experiment replicates the temporal-binding effect and simultaneously measures participants' sense of agency over their actions. The results show that both the temporal-binding effect and the sense of agency we have over our own actions is disrupted under the startle paradigm in line with the theory that these phenomena both rely on forward models. Furthermore, this experiment provides evidence in support of the claim that a startle-induced action is qualitatively different from other actions.
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25
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McInnes AN, Castellote JM, Kofler M, Honeycutt CF, Lipp OV, Riek S, Tresilian JR, Marinovic W. Cumulative distribution functions: An alternative approach to examine the triggering of prepared motor actions in the StartReact effect. Eur J Neurosci 2020; 53:1545-1568. [PMID: 32935412 DOI: 10.1111/ejn.14973] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 09/02/2020] [Indexed: 11/29/2022]
Abstract
There has been much debate concerning whether startling sensory stimuli can activate a fast-neural pathway for movement triggering (StartReact) which is different from that of voluntary movements. Activity in sternocleidomastoid (SCM) electromyogram is suggested to indicate activation of this pathway. We evaluated whether SCM activity can accurately identify trials which may differ in their neurophysiological triggering and assessed the use of cumulative distribution functions (CDFs) of reaction time (RT) data to identify trials with the shortest RTs for analysis. Using recent data sets from the StartReact literature, we examined the relationship between RT and SCM activity. We categorised data into short/longer RT bins using CDFs and used linear mixed-effects models to compare potential conclusions that can be drawn when categorising data on the basis of RT versus on the basis of SCM activity. The capacity of SCM to predict RT is task-specific, making it an unreliable indicator of distinct neurophysiological mechanisms. Classification of trials using CDFs is capable of capturing potential task- or muscle-related differences in triggering whilst avoiding the pitfalls of the traditional SCM activity-based classification method. We conclude that SCM activity is not always evident on trials that show the early triggering of movements seen in the StartReact phenomenon. We further propose that a more comprehensive analysis of data may be achieved through the inclusion of CDF analyses. These findings have implications for future research investigating movement triggering as well as for potential therapeutic applications of StartReact.
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Affiliation(s)
| | - Juan M Castellote
- National School of Occupational Medicine, Carlos III Institute of Health, and Faculty of Medicine, Complutense University, Madrid, Spain
| | - Markus Kofler
- Department of Neurology, Hochzirl Hospital, Zirl, Austria
| | - Claire F Honeycutt
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ, USA
| | - Ottmar V Lipp
- School of Psychology, Curtin University, Perth, Australia
| | - Stephan Riek
- Graduate Research School, University of the Sunshine Coast, and School of Human Movement and Nutrition Sciences, University of Queensland, Brisbane, Australia
| | - James R Tresilian
- Department of Psychology, University of Warwick, Coventry, United Kingdom
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Nonnekes J, Dibilio V, Barthel C, Solis-Escalante T, Bloem BR, Weerdesteyn V. Understanding the dual-task costs of walking: a StartReact study. Exp Brain Res 2020; 238:1359-1364. [PMID: 32355996 PMCID: PMC7237398 DOI: 10.1007/s00221-020-05817-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 04/17/2020] [Indexed: 10/27/2022]
Abstract
The need to perform multiple tasks more or less simultaneously is a common occurrence during walking in daily life. Performing tasks simultaneously typically impacts task performance negatively. Hypothetically, such dual-task costs may be explained by a lowered state of preparation due to competition for attentional resources, or alternatively, by a 'bottleneck' in response initiation. Here, we investigated both hypotheses by comparing 'StartReact' effects during a manual squeezing task under single-task (when seated) and dual-task (when walking) conditions. StartReact is the acceleration of reaction times by a startling stimulation (a startling acoustic stimulus was applied in 25% of trials), attributed to the startling stimulus directly releasing a pre-prepared movement. If dual-task costs are due to a lowered state of preparation, we expected trials both with and without an accompanying startling stimulus to be delayed compared to the single-task condition, whereas we expected only trials without a startling stimulus to be delayed if a bottleneck in response initiation would underlie dual-task costs. Reaction times of the manual squeezing task in the flexor digitorum superficialis and extensor carpi radialis muscle were significantly delayed (approx. 20 ms) when walking compared to the seated position. A startling acoustic stimulus significantly decreased reaction times of the squeezing task (approx. 60 ms) both when walking and sitting. Dual-task costs during walking are, therefore, likely the result of lowered task preparation because of competition for attentional resources.
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Affiliation(s)
- Jorik Nonnekes
- Department of Rehabilitation, Radboud University Medical Centre, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands. .,Sint Maartenskliniek Research, Nijmegen, The Netherlands.
| | - Valeria Dibilio
- Department of Rehabilitation, Radboud University Medical Centre, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands.,IRCCS Centro Neurolesi Bonino Pulejo, Messina, Italy
| | - Claudia Barthel
- Department of Neurology, Radboud University Medical Centre, Donders Institute for Brain, Cognition and Behaviour, Centre of Expertise for Parkinson and Movement Disorders, Nijmegen, The Netherlands.,SRH University of Applied Health Sciences, Gera, Campus Stuttgart, Stuttgart, Germany
| | - Teodoro Solis-Escalante
- Department of Rehabilitation, Radboud University Medical Centre, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| | - Bastiaan R Bloem
- Department of Neurology, Radboud University Medical Centre, Donders Institute for Brain, Cognition and Behaviour, Centre of Expertise for Parkinson and Movement Disorders, Nijmegen, The Netherlands
| | - Vivian Weerdesteyn
- Department of Rehabilitation, Radboud University Medical Centre, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands.,Sint Maartenskliniek Research, Nijmegen, The Netherlands
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27
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Ibáñez J, Hannah R, Rocchi L, Rothwell JC. Premovement Suppression of Corticospinal Excitability may be a Necessary Part of Movement Preparation. Cereb Cortex 2019; 30:2910-2923. [DOI: 10.1093/cercor/bhz283] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 10/15/2019] [Accepted: 10/23/2019] [Indexed: 12/29/2022] Open
Abstract
Abstract
In reaction time (RT) tasks corticospinal excitability (CSE) rises just prior to movement. This is preceded by a paradoxical reduction in CSE, when the time of the imperative (“GO”) stimulus is relatively predictable. Because RT tasks emphasise speed of response, it is impossible to distinguish whether reduced CSE reflects a mechanism for withholding prepared actions, or whether it is an inherent part of movement preparation. To address this question, we used transcranial magnetic stimulation (TMS) to estimate CSE changes preceding 1) RT movements; 2) movements synchronized with a predictable signal (predictive timing or PT movements); and 3) self-paced movements. Results show that CSE decreases with a similar temporal profile in all three cases, suggesting that it reflects a previously unrecognised state in the transition between rest and movement. Although TMS revealed reduced CSE in all movements, the TMS pulse itself had different effects on movement times. TMS given ~200 ms before the times to move speeded the onset of RT and self-paced movements, suggesting that their initiation depends on a form of trigger that can be conditioned by external events. On the contrary, PT movements did not show this effect, suggesting the use of a different triggering strategy prioritizing internal events.
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Affiliation(s)
- J Ibáñez
- Department of Clinical and Movement Disorders, Institute of Neurology, University College London, London WC1N 3BG, UK
- Department of Bioengineering, Faculty of Engineering, Imperial College London, London SW7 2AZ, UK
| | - R Hannah
- Department of Clinical and Movement Disorders, Institute of Neurology, University College London, London WC1N 3BG, UK
- Department of Psychology, University of California, San Diego, CA 92093, USA
| | - L Rocchi
- Department of Clinical and Movement Disorders, Institute of Neurology, University College London, London WC1N 3BG, UK
| | - J C Rothwell
- Department of Clinical and Movement Disorders, Institute of Neurology, University College London, London WC1N 3BG, UK
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29
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Smith V, Maslovat D, Carlsen AN. StartReact effects are dependent on engagement of startle reflex circuits: support for a subcortically mediated initiation pathway. J Neurophysiol 2019; 122:2541-2547. [PMID: 31642402 DOI: 10.1152/jn.00505.2019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The "StartReact" effect refers to the rapid involuntary triggering of a prepared movement in response to a loud startling acoustic stimulus (SAS). This effect is typically confirmed by the presence of short-latency electromyographic activity in startle reflex-related muscles such as the sternocleidomastoid (SCM); however, there is debate regarding the specific neural pathways involved in the StartReact effect. Some research has implicated a subcortically mediated pathway, which would predict different response latencies depending on the presence of a startle reflex. Alternatively, other research has suggested that this effect involves the same pathways responsible for voluntary response initiation and simply reflects higher preparatory activation levels, and thus faster voluntary initiation. To distinguish between these competing hypotheses, the present study assessed preparation level during a simple reaction time (RT) task involving wrist extension in response to a control tone or a SAS. Premotor RT and startle circuitry engagement (as measured by SCM activation) were determined for each trial. Additionally, preparation level at the go signal on each trial was measured using motor-evoked potentials (MEP) elicited by transcranial magnetic stimulation (TMS). Results showed that SAS trial RTs were significantly shorter (P = 0.009) in the presence of startle-related SCM activity. Nevertheless, preparation levels (as indexed by MEP amplitude) were statistically equivalent between trials with and without SCM activation. These results indicate that the StartReact effect relates to engagement of the startle reflex circuitry rather than simply being a result of an increased level of preparatory activation.NEW & NOTEWORTHY The neural mechanism underlying the early triggering of goal-directed actions by a startling acoustic stimulus (SAS) is unclear. We show that although significant reaction time differences were evident depending on whether the SAS elicited a startle reflex, motor preparatory activation was the same. Thus, in a highly prepared state, the short-latency responses associated with the StartReact effect appear to be related to engagement of startle reflex circuitry, not differences in motor preparatory level.
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Affiliation(s)
- Victoria Smith
- School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - Dana Maslovat
- School of Kinesiology, University of British Columbia, British Columbia, Canada
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30
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Uncertainty in when a perturbation will arrive influences the preparation and release of triggered responses. Exp Brain Res 2019; 237:2353-2365. [PMID: 31292693 DOI: 10.1007/s00221-019-05592-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 06/22/2019] [Indexed: 01/06/2023]
Abstract
The timing and magnitude of muscle responses to perturbations are critical for acting in uncertain environments. A planned movement can strongly influence average muscle responses to perturbations, but certainty in when a perturbation will arrive changes this effect. The objective of this study was to investigate how uncertainty in perturbation timing influences the preparation and release of involuntary, perturbation-triggered responses. We hypothesized that uncertainty would influence the average magnitude of triggered responses and how they develop in time. We investigated three levels of uncertainty in when a proprioceptive cue to move would arrive by changing the duration and variability of the time between a preparation and movement cue. Participants performed ballistic elbow extension movements in response to the movement cue. Unexpected, large perturbations that flexed the elbow were delivered at various times between the preparation and movement cues to evaluate how cue uncertainty influenced the development of triggered responses. We found that this uncertainty strongly influences how a motor response is prepared, and the efficacy of triggering that response by a postural perturbation. When timing was certain, the motor plan was prepared within 150 ms of the expected disturbance, and consistently released earlier by a perturbation than could be done voluntarily. Less predictable stimuli led to much earlier planning and a lower probability of releasing the plan early. These results clarify how uncertainty in when to move influences the planning and early release of perturbation-triggered responses, demonstrating an effect similar to previous reports on the planning of volitional movements.
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31
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Perera T, Tan JL, Cole MH, Yohanandan SAC, Silberstein P, Cook R, Peppard R, Aziz T, Coyne T, Brown P, Silburn PA, Thevathasan W. Balance control systems in Parkinson's disease and the impact of pedunculopontine area stimulation. Brain 2019; 141:3009-3022. [PMID: 30165427 PMCID: PMC6158752 DOI: 10.1093/brain/awy216] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 06/26/2018] [Indexed: 11/23/2022] Open
Abstract
Impaired balance is a major contributor to falls and diminished quality of life in Parkinson’s disease, yet the pathophysiology is poorly understood. Here, we assessed if patients with Parkinson’s disease and severe clinical balance impairment have deficits in the intermittent and continuous control systems proposed to maintain upright stance, and furthermore, whether such deficits are potentially reversible, with the experimental therapy of pedunculopontine nucleus deep brain stimulation. Two subject groups were assessed: (i) 13 patients with Parkinson’s disease and severe clinical balance impairment, implanted with pedunculopontine nucleus deep brain stimulators; and (ii) 13 healthy control subjects. Patients were assessed in the OFF medication state and blinded to two conditions; off and on pedunculopontine nucleus stimulation. Postural sway data (deviations in centre of pressure) were collected during quiet stance using posturography. Intermittent control of sway was assessed by calculating the frequency of intermittent switching behaviour (discontinuities), derived using a wavelet-based transformation of the sway time series. Continuous control of sway was assessed with a proportional–integral–derivative (PID) controller model using ballistic reaction time as a measure of feedback delay. Clinical balance impairment was assessed using the ‘pull test’ to rate postural reflexes and by rating attempts to arise from sitting to standing. Patients with Parkinson’s disease demonstrated reduced intermittent switching of postural sway compared with healthy controls. Patients also had abnormal feedback gains in postural sway according to the PID model. Pedunculopontine nucleus stimulation improved intermittent switching of postural sway, feedback gains in the PID model and clinical balance impairment. Clinical balance impairment correlated with intermittent switching of postural sway (rho = − 0.705, P < 0.001) and feedback gains in the PID model (rho = 0.619, P = 0.011). These results suggest that dysfunctional intermittent and continuous control systems may contribute to the pathophysiology of clinical balance impairment in Parkinson’s disease. Clinical balance impairment and their related control system deficits are potentially reversible, as demonstrated by their improvement with pedunculopontine nucleus deep brain stimulation.
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Affiliation(s)
- Thushara Perera
- The Bionics Institute, East Melbourne, Victoria, Australia.,Department of Medical Bionics, The University of Melbourne, Parkville, Victoria, Australia
| | - Joy L Tan
- The Bionics Institute, East Melbourne, Victoria, Australia.,Department of Medical Bionics, The University of Melbourne, Parkville, Victoria, Australia
| | - Michael H Cole
- School of Exercise Science, Australian Catholic University, Brisbane, Queensland, Australia
| | | | - Paul Silberstein
- Royal North Shore and North Shore Private Hospitals, Sydney, New South Wales, Australia
| | - Raymond Cook
- Royal North Shore and North Shore Private Hospitals, Sydney, New South Wales, Australia
| | - Richard Peppard
- The Bionics Institute, East Melbourne, Victoria, Australia.,Clinical Neurosciences, St Vincent's Hospital, Melbourne, Victoria, Australia
| | - Tipu Aziz
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford OX1 3TH, UK
| | - Terry Coyne
- Asia-Pacific Centre for Neuromodulation, Queensland Brain Institute, The University of Queensland, Brisbane, Queensland, Australia
| | - Peter Brown
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford OX1 3TH, UK.,Medical Research Council Brain Network Dynamics Unit, University of Oxford, Oxford OX1 3TH, UK
| | - Peter A Silburn
- Asia-Pacific Centre for Neuromodulation, Queensland Brain Institute, The University of Queensland, Brisbane, Queensland, Australia
| | - Wesley Thevathasan
- The Bionics Institute, East Melbourne, Victoria, Australia.,Departments of Neurology, The Royal Melbourne and Austin Hospitals, Victoria, Australia.,Department of Medicine, The University of Melbourne, Parkville, Victoria, Australia
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Garcia-Rill E, Saper CB, Rye DB, Kofler M, Nonnekes J, Lozano A, Valls-Solé J, Hallett M. Focus on the pedunculopontine nucleus. Consensus review from the May 2018 brainstem society meeting in Washington, DC, USA. Clin Neurophysiol 2019; 130:925-940. [PMID: 30981899 PMCID: PMC7365492 DOI: 10.1016/j.clinph.2019.03.008] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 03/15/2019] [Accepted: 03/22/2019] [Indexed: 12/12/2022]
Abstract
The pedunculopontine nucleus (PPN) is located in the mesopontine tegmentum and is best delimited by a group of large cholinergic neurons adjacent to the decussation of the superior cerebellar peduncle. This part of the brain, populated by many other neuronal groups, is a crossroads for many important functions. Good evidence relates the PPN to control of reflex reactions, sleep-wake cycles, posture and gait. However, the precise role of the PPN in all these functions has been controversial and there still are uncertainties in the functional anatomy and physiology of the nucleus. It is difficult to grasp the extent of the influence of the PPN, not only because of its varied functions and projections, but also because of the controversies arising from them. One controversy is its relationship to the mesencephalic locomotor region (MLR). In this regard, the PPN has become a new target for deep brain stimulation (DBS) for the treatment of parkinsonian gait disorders, including freezing of gait. This review is intended to indicate what is currently known, shed some light on the controversies that have arisen, and to provide a framework for future research.
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Affiliation(s)
- E Garcia-Rill
- Center for Translational Neuroscience, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
| | - C B Saper
- Department of Neurology, Division of Sleep Medicine and Program in Neuroscience, Harvard Medical School, Boston, MA, USA
| | - David B Rye
- Department of Neurology, Division of Sleep Medicine and Program in Neuroscience, Harvard Medical School, Boston, MA, USA
| | - M Kofler
- Department of Neurology, Hochzirl Hospital, Zirl, Austria
| | - J Nonnekes
- Radboud University Medical Centre, Donders Institute for Brain, Cognition and Behaviour, Department of Rehabilitation, Nijmegen, the Netherlands
| | - A Lozano
- Division of Neurosurgery, University of Toronto and Krembil Neuroscience Centre, University Health Network, Toronto, Canada
| | - J Valls-Solé
- Neurology Department, Hospital Clínic, University of Barcelona, IDIBAPS (Institut d'Investigació Biomèdica August Pi i Sunyer), Barcelona, Spain
| | - M Hallett
- Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
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Smith V, Maslovat D, Drummond NM, Hajj J, Leguerrier A, Carlsen AN. High-intensity transcranial magnetic stimulation reveals differential cortical contributions to prepared responses. J Neurophysiol 2019; 121:1809-1821. [PMID: 30864866 DOI: 10.1152/jn.00510.2018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Corticospinal output pathways have typically been considered to be the primary driver for voluntary movements of the hand/forearm; however, more recently, reticulospinal drive has also been implicated in the production of these movements. Although both pathways may play a role, the reticulospinal tract is thought to have stronger connections to flexor muscles than to extensors. Similarly, movements involuntarily triggered via a startling acoustic stimulus (SAS) are believed to receive greater reticular input than voluntary movements. To investigate a differential role of reticulospinal drive depending on movement type or acoustic stimulus, corticospinal drive was transiently interrupted using high-intensity transcranial magnetic stimulation (TMS) applied during the reaction time (RT) interval. This TMS-induced suppression of cortical drive leads to RT delays that can be used to assess cortical contributions to movement. Participants completed targeted flexion and extension movements of the wrist in a simple RT paradigm in response to a control auditory go signal or SAS. Occasionally, suprathreshold TMS was applied over the motor cortical representation for the prime mover. Results revealed that TMS significantly increased RT in all conditions. There was a significantly longer TMS-induced RT delay seen in extension movements than in flexion movements and a greater RT delay in movements initiated in response to control stimuli compared with SAS. These results suggest that the contribution of reticulospinal drive is larger for wrist flexion than for extension. Similarly, movements triggered involuntarily by an SAS appear to involve greater reticulospinal drive, and relatively less corticospinal drive, than those that are voluntarily initiated. NEW & NOTEWORTHY Through the use of the transcranial magnetic stimulation-induced silent period, we provide novel evidence for a greater contribution of reticulospinal drive, and a relative decrease in corticospinal drive, to movements involuntarily triggered by a startle compared with voluntary movements. These results also provide support for the notion that both cortical and reticular structures are involved in the neural pathway underlying startle-triggered movements. Furthermore, our results indicate greater reticulospinal contribution to wrist flexion than extension movements.
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Affiliation(s)
- Victoria Smith
- School of Human Kinetics, University of Ottawa , Ottawa, Ontario , Canada
| | - Dana Maslovat
- School of Kinesiology, University of British Columbia , Vancouver, British Columbia , Canada
| | - Neil M Drummond
- School of Human Kinetics, University of Ottawa , Ottawa, Ontario , Canada
| | - Joëlle Hajj
- School of Human Kinetics, University of Ottawa , Ottawa, Ontario , Canada
| | | | - Anthony N Carlsen
- School of Human Kinetics, University of Ottawa , Ottawa, Ontario , Canada
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34
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A Timeline of Motor Preparatory State Prior to Response Initiation: Evidence from Startle. Neuroscience 2019; 397:80-93. [DOI: 10.1016/j.neuroscience.2018.11.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 11/06/2018] [Accepted: 11/13/2018] [Indexed: 11/23/2022]
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35
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Castellote JM, Kofler M. StartReact effects in first dorsal interosseous muscle are absent in a pinch task, but present when combined with elbow flexion. PLoS One 2018; 13:e0201301. [PMID: 30048503 PMCID: PMC6062078 DOI: 10.1371/journal.pone.0201301] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 07/12/2018] [Indexed: 11/28/2022] Open
Abstract
Objective To provide a neurophysiological tool for assessing sensorimotor pathways, which may differ for those involving distal muscles in simple tasks from those involving distal muscles in a kinetic chain task, or proximal muscles in both. Methods We compared latencies and magnitudes of motor responses in a reaction time paradigm in a proximal (biceps brachii, BB) and a distal (first dorsal interosseous, FDI) muscle following electrical stimuli used as imperative signal (IS) delivered to the index finger. These stimuli were applied during different motor tasks: simple tasks involving either one muscle, e.g. flexing the elbow for BB (FLEX), or pinching a pen for FDI (PINCH); combined tasks engaging both muscles by pinching and flexing simultaneously (PINCH-FLEX). Stimuli were of varying intensity and occasionally elicited a startle response, and a StartReact effect. Results In BB, response latencies decreased gradually and response amplitudes increased progressively with increasing IS intensities for non-startling trials, while for trials containing startle responses, latencies were uniformly shortened and response amplitudes similarly augmented across all IS intensities in both FLEX and PINCH-FLEX. In FDI, response latencies decreased gradually and response amplitudes increased progressively with increasing IS intensities in both PINCH and PINCH-FLEX for non-startling trials, but, unlike in BB for the simple task, in PINCH for trials containing startle responses as well. In PINCH-FLEX, FDI latencies were uniformly shortened and amplitudes similarly increased across all stimulus intensities whenever startle signs were present. Conclusions Our results suggest the presence of different sensorimotor pathways supporting a dissociation between simple tasks that involve distal upper limb muscles (FDI in PINCH) from simple tasks involving proximal muscles (BB in FLEX), and combined tasks that engage both muscles (FDI and BB in PINCH-FLEX), all in accordance with differential importance in the control of movements by cortical and subcortical structures. Significance Simple assessment tools may provide useful information regarding the differential involvement of sensorimotor pathways in the control of both simple and combined tasks that engage proximal and distal muscles.
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Affiliation(s)
- Juan M. Castellote
- National School of Occupational Medicine, Carlos III Institute of Health, Madrid, Spain
- Radiology, Rehabilitation and Physiotherapy, Complutense University of Madrid, Madrid, Spain
- * E-mail:
| | - Markus Kofler
- Department of Neurology, Hochzirl Hospital, Zirl, Austria
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36
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The bottleneck of the psychological refractory period effect involves timing of response initiation rather than response selection. Psychon Bull Rev 2018; 26:29-47. [DOI: 10.3758/s13423-018-1498-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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37
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Properties of short-latency responses in the upper limbs evoked by axial impulses during leaning: evidence for reticulospinal projections. Exp Brain Res 2018; 236:2611-2618. [DOI: 10.1007/s00221-018-5320-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 06/25/2018] [Indexed: 10/28/2022]
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38
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Ticini LF, Schütz-Bosbach S, Waszak F. Mirror and (absence of) counter-mirror responses to action sounds measured with TMS. Soc Cogn Affect Neurosci 2018; 12:1748-1757. [PMID: 29036454 PMCID: PMC5691549 DOI: 10.1093/scan/nsx106] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 09/06/2017] [Indexed: 11/14/2022] Open
Abstract
To what extent is the mirror neuron mechanism malleable to experience? The answer to this question can help characterising its ontogeny and its role in social cognition. Some suggest that it develops through sensorimotor associations congruent with our own actions. Others argue for its extreme volatility that will encode any sensorimotor association in the environment. Here, we added to this debate by exploring the effects of short goal-directed 'mirror' and 'counter-mirror' trainings (a 'mirror' training is defined as the first type of training encountered by the participants) on human auditory mirror motor-evoked potentials (MEPs). We recorded MEPs in response to two tones void of previous motor meaning, before and after mirror and counter-mirror trainings in which participants generated two tones of different pitch by performing free-choice button presses. The results showed that mirror MEPs, once established, were protected against an equivalent counter-mirror experience: they became manifest very rapidly and the same number of training trials that lead to the initial association did not suffice to reverse the MEP pattern. This steadiness of the association argues that, by serving direct-matching purposes, the mirror mechanism is a good solution for social cognition.
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Affiliation(s)
- Luca F Ticini
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester M13 9PL, UK
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O'Neill J, Hartman ME, O'Neill DA, Lewinski WJ. Further analysis of the unintentional discharge of firearms in law enforcement. APPLIED ERGONOMICS 2018; 68:267-272. [PMID: 29409643 DOI: 10.1016/j.apergo.2017.12.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 12/11/2017] [Indexed: 06/07/2023]
Abstract
Empirical analysis of the contexts in which UDs occur in law enforcement have only recently begun to emerge. We analyzed a novel sample of UD reports (N = 171) that occurred between 1992 and 2016, collected from one non-U.S. and three U.S. law enforcement entities. Using an established antecedent-behavior-consequence (A-B-C) taxonomy, reports were analyzed by context, officer behavior, type of firearm, injuries, deaths, and property damages. This study is the first to empirically document reports of UDs caused by the startle response and the first to analyze a substantial sample of UDs that involved handguns with a double-action only trigger mechanism. An expanded analysis of UD consequences suggested that deaths and injuries might be more prevalent than previously reported.
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Affiliation(s)
- John O'Neill
- Division of Research, Force Science(®) Institute Ltd., Mankato, MN 56001, USA.
| | - Mark E Hartman
- Division of Research, Force Science(®) Institute Ltd., Mankato, MN 56001, USA; Department of Kinesiology, Iowa State University, Ames, IA 50011, USA
| | - Dawn A O'Neill
- Division of Research, Force Science(®) Institute Ltd., Mankato, MN 56001, USA
| | - William J Lewinski
- Division of Research, Force Science(®) Institute Ltd., Mankato, MN 56001, USA
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40
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Maurer C, Heller S, Sure JJ, Fuchs D, Mickel C, Wanke EM, Groneberg DA, Ohlendorf D. Strength improvements through occlusal splints? The effects of different lower jaw positions on maximal isometric force production and performance in different jumping types. PLoS One 2018; 13:e0193540. [PMID: 29474465 PMCID: PMC5825140 DOI: 10.1371/journal.pone.0193540] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 01/29/2018] [Indexed: 11/19/2022] Open
Abstract
Objective The influence of the jaw position on postural control, body posture, walking and running pattern has been reported in the literature. All these movements have in common that a relatively small, but well controlled muscle activation is required. The induced effects on motor output through changed jaw positions have been small. Therefore, it has been questioned if it could still be observed in maximal muscle activation. Method Twenty-three healthy, mid age recreational runners (mean age = 34.0 ± 10.3 years) participated in this study. Three different jump tests (squat jump, counter movement jump, and drop jumps from four different heights) and three maximal strength tests (trunk flexion and extension, leg press of the right and left leg) were conducted. Four different dental occlusion conditions and an additional familiarization condition were tested. Subjects performed the tests on different days for which the four occlusion conditions were randomly changed. Results No familiarization effect was found. Occlusion conditions with a relaxation position and with a myocentric condylar position showed significantly higher values for several tests compared to the neutral condition and the maximal occlusion position. Significance was found in the squat jump, countermovement jump, the drop jump from 32cm and 40cm, trunk extension, leg press force and rate of force development. The effect due to the splint conditions is an improvement between 3% and 12% (min and max). No influence of the jaw position on symmetry or balance between extension and flexion muscle was found. Conclusion An influence of occlusion splints on rate of force development (RFD) and maximal strength tests could be confirmed. A small, but consistent increase in the performance parameters could be measured. The influence of the occlusion condition is most likely small compared to other influences as for example training status, age, gender and circadian rhythm.
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Affiliation(s)
| | - Sebastian Heller
- Department of Movement and Exercise Science, Institute of Sport Sciences, Goethe-University Frankfurt/Main, Frankfurt am Main, Germany
| | - Jil-Julia Sure
- Institute of Occupational Medicine, Social Medicine and Environmental Medicine, Goethe University Frankfurt/Main, Frankfurt am Main, Germany
| | - Daniel Fuchs
- Institute of Occupational Medicine, Social Medicine and Environmental Medicine, Goethe University Frankfurt/Main, Frankfurt am Main, Germany
| | - Christoph Mickel
- Department of Movement and Exercise Science, Institute of Sport Sciences, Goethe-University Frankfurt/Main, Frankfurt am Main, Germany
| | - Eileen M. Wanke
- Institute of Occupational Medicine, Social Medicine and Environmental Medicine, Goethe University Frankfurt/Main, Frankfurt am Main, Germany
| | - David A. Groneberg
- Institute of Occupational Medicine, Social Medicine and Environmental Medicine, Goethe University Frankfurt/Main, Frankfurt am Main, Germany
| | - Daniela Ohlendorf
- Institute of Occupational Medicine, Social Medicine and Environmental Medicine, Goethe University Frankfurt/Main, Frankfurt am Main, Germany
- * E-mail:
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41
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Smith V, Carlsen AN. Sub-threshold transcranial magnetic stimulation applied after the go-signal facilitates reaction time under control but not startle conditions. Eur J Neurosci 2018; 47:333-345. [PMID: 29356214 DOI: 10.1111/ejn.13827] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 01/03/2018] [Accepted: 01/11/2018] [Indexed: 11/29/2022]
Abstract
The presentation of a startling acoustic stimulus (SAS) in a simple reaction time (RT) task significantly reduces RT due to the involuntary early initiation of a prepared movement; however, the underlying neural mechanism remains unclear. It has been proposed that a SAS triggers a cortically stored motor program by involuntarily increasing initiation-related activation. Sub-threshold transcranial magnetic stimulation (TMS) can be used to investigate cortical processes, as it increases cortical excitability for 6-30 ms and significantly reduces RT. The purpose of the present experiments was to determine whether the application of sub-threshold TMS over motor cortex in close temporal proximity to a SAS would facilitate startle RT in the same manner as control RT, providing evidence for cortical involvement in startle-related RTs. Participants completed a simple RT task requiring targeted wrist extension in response to an auditory go-signal, which was randomly replaced by a SAS on 25% of trials. On a subset of trials, sub-threshold TMS was applied 30 ms following the go-signal in control trials or at -15, 0, +15 or +30 ms with respect to the SAS in startle trials. In all three experiments, sham and real TMS significantly reduced RT in control trials, with real TMS having a larger effect, but there was no effect of either real or sham TMS on startle-related RT. These results suggest that there may be limited cortical involvement in the initiation of movements in response to a SAS. As an alternative, startle may produce the fastest possible RTs, with little room for additional facilitation.
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Affiliation(s)
- Victoria Smith
- School of Human Kinetics, University of Ottawa, 125 University Private, Ottawa, ON, Canada
| | - Anthony N Carlsen
- School of Human Kinetics, University of Ottawa, 125 University Private, Ottawa, ON, Canada
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42
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Does trait anxiety influence effects of oxytocin on eye-blink startle reactivity? A randomized, double-blind, placebo-controlled crossover study. PLoS One 2018; 13:e0190809. [PMID: 29300752 PMCID: PMC5754118 DOI: 10.1371/journal.pone.0190809] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2017] [Accepted: 12/20/2017] [Indexed: 11/19/2022] Open
Abstract
Background Previous research has demonstrated that the neuropeptide oxytocin modulates social behaviors and reduces anxiety. However, effects of oxytocin on startle reactivity, a well-validated measure of defense system activation related to fear and anxiety, have been inconsistent. Here we investigated the influence of oxytocin on startle reactivity with particular focus on the role of trait anxiety. Methods Forty-four healthy male participants attended two experimental sessions. They received intranasal oxytocin (24 IU) in one session and placebo in the other. Startle probes were presented in combination with pictures of social and non-social content. Eye-blink startle magnitude was measured by electromyography over the musculus orbicularis oculi in response to 95 dB noise bursts. Participants were assigned to groups of high vs. low trait anxiety based on their scores on the trait form of the Spielberger State-Trait Anxiety Inventory (STAI). Results A significant interaction effect of oxytocin with STAI confirmed that trait anxiety moderated the effect of oxytocin on startle reactivity. Post-hoc tests indicated that for participants with elevated trait anxiety, oxytocin increased startle magnitude, particularly when watching non-social pictures, while this was not the case for participants with low trait anxiety. Conclusion Results indicate that effects of oxytocin on defense system activation depend on individual differences in trait anxiety. Trait anxiety may be an important moderator variable that should be considered in human studies on oxytocin effects.
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43
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Forgaard CJ, Franks IM, Bennett K, Maslovat D, Chua R. Mechanical perturbations can elicit triggered reactions in the absence of a startle response. Exp Brain Res 2017; 236:365-379. [PMID: 29151141 DOI: 10.1007/s00221-017-5134-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 11/14/2017] [Indexed: 10/18/2022]
Abstract
Perturbations delivered to the upper limbs elicit reflexive responses in stretched muscle at short- (M1: 25-50 ms) and long- (M2: 50-100 ms) latencies. When presented in a simple reaction time (RT) task, the perturbation can also elicit a preprogrammed voluntary response at a latency (< 100 ms) that overlaps the M2 response. This early appearance of the voluntary response following a proprioceptive stimulus causing muscle stretch is called a triggered reaction. Recent work has demonstrated that a perturbation also elicits activity in sternocleidomastoid (SCM) over a time-course consistent with the startle response and it was, therefore, proposed that the StartReact effect underlies triggered reactions (Ravichandran et al., Exp Brain Res 230:59-69, 2013). The present work investigated whether perturbation-evoked SCM activity results from startle or postural control and whether triggered reactions can also occur in the absence of startle. In Experiment 1, participants "compensated" against a wrist extension perturbation. A prepulse inhibition (PPI) stimulus (known to attenuate startle) was randomly presented before the perturbation. Rather than attenuating SCM activity, the responses in SCM were advanced by the PPI stimulus. In Experiment 2, participants "assisted" a wrist extension perturbation. The perturbation did not reliably elicit startle but despite this, two-thirds of trials had RTs of less than 100 ms and the earliest responses began at ~ 70 ms. These findings suggest that SCM activity following a perturbation is the result of postural control and is not related to startle. Moreover, an overt startle response is not a prerequisite for the elicitation of a triggered reaction.
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Affiliation(s)
- Christopher J Forgaard
- School of Kinesiology, University of British Columbia, War Memorial Gymnasium 210-6081 University Boulevard, Vancouver, BC, V6T 1Z1, Canada.
| | - Ian M Franks
- School of Kinesiology, University of British Columbia, War Memorial Gymnasium 210-6081 University Boulevard, Vancouver, BC, V6T 1Z1, Canada
| | - Kimberly Bennett
- School of Kinesiology, University of British Columbia, War Memorial Gymnasium 210-6081 University Boulevard, Vancouver, BC, V6T 1Z1, Canada
| | - Dana Maslovat
- School of Kinesiology, University of British Columbia, War Memorial Gymnasium 210-6081 University Boulevard, Vancouver, BC, V6T 1Z1, Canada
| | - Romeo Chua
- School of Kinesiology, University of British Columbia, War Memorial Gymnasium 210-6081 University Boulevard, Vancouver, BC, V6T 1Z1, Canada
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Maslovat D, Carter MJ, Carlsen AN. Response preparation and execution during intentional bimanual pattern switching. J Neurophysiol 2017; 118:1720-1731. [PMID: 28659461 PMCID: PMC5596139 DOI: 10.1152/jn.00323.2017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 06/27/2017] [Accepted: 06/27/2017] [Indexed: 11/22/2022] Open
Abstract
During continuous bimanual coordination, in-phase (IP; 0° relative phase) and anti-phase (AP; 180° relative phase) patterns can be stably performed without practice. Paradigms in which participants are required to intentionally switch between these coordination patterns have been used to investigate the interaction between the performer's intentions and intrinsic dynamics of the body's preferred patterns. The current study examined the processes associated with switching preparation and execution through the use of a startling acoustic stimulus (SAS) as the switch stimulus. A SAS is known to involuntarily trigger preprogrammed responses at a shortened latency and, thus, can be used to probe advance preparation. Participants performed cyclical IP and AP bimanual elbow extension-flexion movements in which they were required to switch patterns in response to an auditory switch cue, which was either nonstartling (80 dB) or a SAS (120 dB). Results indicated that reaction time to the switch stimulus (i.e., switch onset) was significantly reduced on startle trials, indicative of advance preparation of the switch response. Similarly, switching time was reduced on startle trials, which was attributed to increased neural activation caused by the SAS. Switching time was also shorter for AP to IP trials, but only when the switching stimulus occurred at either the midpoint or reversal locations within the movement cycle, suggesting that the switch location may affect the intrinsic dynamics of the system.NEW & NOTEWORTHY The current study provides novel information regarding preparation and execution of intentional switching between in-phase and anti-phase bimanual coordination patterns. Using a startling acoustic stimulus, we provide strong evidence that the switching response is prepared before the switch stimulus, and switch execution is accelerated by the startling stimulus. In addition, the time required to switch between patterns and relative limb contribution is dependent upon where in the movement cycle the switch stimulus occurred.
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Affiliation(s)
- Dana Maslovat
- School of Kinesiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Michael J Carter
- Centre for Neuroscience Studies, Queen's University, Kingston, Ontario, Canada; and
| | - Anthony N Carlsen
- School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada
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Evidence for Startle Effects due to Externally Induced Lower Limb Movements: Implications in Neurorehabilitation. BIOMED RESEARCH INTERNATIONAL 2017; 2017:8471546. [PMID: 28299334 PMCID: PMC5337331 DOI: 10.1155/2017/8471546] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 01/10/2017] [Accepted: 01/19/2017] [Indexed: 11/17/2022]
Abstract
Passive limb displacement is routinely used to assess muscle tone. If we attempt to quantify muscle stiffness using mechanical devices, it is important to know whether kinematic stimuli are able to trigger startle reactions. Whether kinematic stimuli are able to elicit a startle reflex and to accelerate prepared voluntary movements (StartReact effect) has not been studied extensively to date. Eleven healthy subjects were suspended in an exoskeleton and were exposed to passive left knee flexion (KF) at three intensities, occasionally replaced by fast right KF. Upon perceiving the movement subjects were asked to perform right wrist extension (WE), assessed by extensor carpi radialis (ECR) electromyographic activity. ECR latencies were shortest in fast trials. Startle responses were present in most fast trials, yet being significantly accelerated and larger with right versus left KF, since the former occurred less frequently and thus less expectedly. Startle responses were associated with earlier and larger ECR responses (StartReact effect), with the largest effect again upon right KF. The results provide evidence that kinematic stimuli are able to elicit both startle reflexes and a StartReact effect, which depend on stimulus intensity and anticipation, as well as on the subjects' preparedness to respond.
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46
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Marker RJ, Campeau S, Maluf KS. Psychosocial stress alters the strength of reticulospinal input to the human upper trapezius. J Neurophysiol 2016; 117:457-466. [PMID: 27832595 DOI: 10.1152/jn.00448.2016] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 10/31/2016] [Indexed: 11/22/2022] Open
Abstract
Psychosocial stress has been shown to influence several aspects of human motor control associated with the fight-or-flight response, including augmentation of upper trapezius muscle activity. Given the established role of the reticular formation in arousal, this study investigated the contribution of reticulospinal activation to trapezius muscle activity during exposure to an acute psychosocial stressor. Twenty-five healthy adults were exposed to startling acoustic stimuli (SAS) while performing a motor task during periods of low and high psychosocial stress. Acoustic startle reflexes (ASRs) were recorded in the upper trapezius during low intensity contractions using both surface and intramuscular electromyography. Exposure to the stressor increased subjective and physiological measures of arousal (P < 0.01). The majority of participants demonstrated inhibitory ASRs, whereas a small subgroup with significantly higher trait anxiety (n = 5) demonstrated excitatory ASRs in the low stress condition. Changes in synaptic input for inhibitory ASRs were confirmed by decreases in the discharge rate of single motor units in response to the SAS. ASRs decreased in magnitude for all participants during exposure to the acute psychosocial stressor. These findings suggest that the reticular formation has predominately inhibitory effects on the human upper trapezius during an ongoing motor task and that disinhibition caused by psychosocial stress may contribute to augmentation of trapezius muscle activity. Further research is required to investigate mechanisms underlying the complex ASRs characterized by this study, particularly the phase reversal to excitatory responses observed among more anxious individuals. NEW & NOTEWORTHY This study is the first to quantify stress-evoked changes in the acoustic startle reflex in the upper trapezius muscle of humans, and our findings reveal a complex pattern of inhibitory and facilitatory responses consistent with observations in nonhuman primates. We further demonstrate that psychosocial stress consistently reduces the amplitude of these responses. These findings have implications for the control of motor behaviors in response to stress.
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Affiliation(s)
- Ryan J Marker
- Rehabilitation Science Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Serge Campeau
- Department of Psychology and Neuroscience, University of Colorado Boulder, Boulder, Colorado; and
| | - Katrina S Maluf
- Rehabilitation Science Program, University of Colorado Anschutz Medical Campus, Aurora, Colorado; .,School of Exercise and Nutritional Sciences, San Diego State University, San Diego, California
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47
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Colebatch JG, Govender S, Dennis DL. Postural responses to anterior and posterior perturbations applied to the upper trunk of standing human subjects. Exp Brain Res 2016; 234:367-76. [PMID: 26487178 PMCID: PMC4731437 DOI: 10.1007/s00221-015-4442-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2015] [Accepted: 09/09/2015] [Indexed: 11/28/2022]
Abstract
This study concerned the effects of brisk perturbations applied to the shoulders of standing subjects to displace them either forwards or backwards, our aim being to characterise the responses to these disturbances. Subjects stood on a force platform, and acceleration was measured at the level of C7, the sacrum and both tibial tuberosities. Surface EMG was measured from soleus (SOL), tibialis anterior (TA), the hamstrings (HS), quadriceps (QUAD), rectus abdominis (RA) and lumbar paraspinal (PS) muscles. Trials were recorded for each of four conditions: subjects' eyes open (reference) or closed and on a firm (reference) or compliant surface. Observations were also made of voluntary postural reactions to a tap over the deltoid. Anterior perturbations (mean C7 acceleration 251.7 mg) evoked activity within the dorsal muscles (SOL, HS, PS) with a similar latency to voluntary responses to shoulder tapping. Responses to posterior perturbations (mean C7 acceleration -240.4 mg) were more complex beginning, on average, at shorter latency than voluntary activity (median TA 78.0 ms). There was activation of TA, QUAD and SOL associated with initial forward acceleration of the lower legs. The EMG responses consisted of an initial phasic discharge followed by a more prolonged one. These responses differ from the pattern of automatic postural responses that follow displacements at the level of the ankles, and it is unlikely that proprioceptive afferents excited by ankle movement had a role in the initial responses. Vision and surface properties had only minor effects. Perturbations of the upper trunk evoke stereotyped compensatory postural responses for each direction of perturbation. For posterior perturbations, EMG onset occurs earlier than for voluntary responses.
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Affiliation(s)
- James G. Colebatch
- />Prince of Wales Clinical School and Neuroscience Research Australia, University of New South Wales, Randwick, Sydney, NSW 2052 Australia
- />Institute of Neurological Sciences, Prince of Wales Hospital, Randwick, Sydney, NSW 2031 Australia
| | - Sendhil Govender
- />Prince of Wales Clinical School and Neuroscience Research Australia, University of New South Wales, Randwick, Sydney, NSW 2052 Australia
| | - Danielle L. Dennis
- />Prince of Wales Clinical School and Neuroscience Research Australia, University of New South Wales, Randwick, Sydney, NSW 2052 Australia
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48
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An examination of the startle response during upper limb stretch perturbations. Neuroscience 2016; 337:163-176. [PMID: 27664458 DOI: 10.1016/j.neuroscience.2016.09.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2016] [Revised: 08/01/2016] [Accepted: 09/08/2016] [Indexed: 12/17/2022]
Abstract
Unexpected presentation of a startling auditory stimulus (SAS>120 decibels) in a reaction time (RT) paradigm results in the startle reflex and an early release (<100ms) of the preplanned motor response (StartReact effect). Mechanical perturbations applied to the upper limbs elicit short- (M1) and long-latency (M2) stretch reflexes and have also been shown to initiate intended motor responses early (<100ms). Ravichandran et al. (2013) recently proposed that unexpected delivery of a perturbation could also elicit a startle response and therefore the StartReact effect may be responsible for the early trigger of a preplanned response. To investigate this further, we examined startle incidence, RT, and stretch reflex modulation for both expected and unexpected perturbations. In Experiment 1, participants performed active (ACT) and passive (DNI) conditions to an expected large perturbation (similar to previous studies examining M2). The startle response was not observed; however, the perturbation still elicited the voluntary response at short latency (<100ms) and goal-dependent modulation of the M2 response was observed. In Experiment 2, participants performed ACT and DNI conditions to a weak auditory stimulus or a small wrist perturbation. On unexpected trials we probed startle circuitry with a large perturbation or SAS. The SAS consistently elicited a startle response in both ACT and DNI conditions, but startle-like activity was only observed on 17.4% of ACT perturbation probe trials. Our findings suggest that while unexpected upper limb perturbations can be startling, startle triggering of the preplanned voluntary response is not the primary mechanism responsible for goal-dependent modulation of the M2 response.
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49
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Investigation of timing preparation during response initiation and execution using a startling acoustic stimulus. Exp Brain Res 2016; 235:15-27. [PMID: 27614459 DOI: 10.1007/s00221-016-4774-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2016] [Accepted: 09/06/2016] [Indexed: 01/07/2023]
Abstract
The purpose of the current study was to examine the processes involved in the preparation of timing during response initiation and execution through the use of a startling acoustic stimulus (SAS). In Experiment 1, participants performed a delayed response task in which a two key-press movement was to be initiated 200 ms after an imperative signal (IS) with either a short (200 ms) or long (500 ms) interval between key-presses. On selected trials, a SAS was presented to probe the preparation processes associated with the initiation delay and execution of the inter-key interval. The SAS resulted in a significant decrease in the initiation time, which was attributed to a speeding of pacemaker pulses used to time the delay interval, caused by an increased activation due to the SAS. Conversely, the SAS delayed the short inter-key interval, which was attributed to temporary interference with cortical processing. In Experiment 2, participants performed a 500-ms delayed response task involving two key-presses 200 ms apart. In this condition, the SAS resulted in significantly decreased initiation time and a delayed inter-key interval (p = .053). Collectively, these results support a different timeline for the preparation of the delay interval, which is thought to be prepared in advance of the IS, and the inter-key interval, which is thought to be prepared following the IS. This conclusion provides novel information with regard to timing preparation that is consistent with models in which response preparation, initiation, and execution are considered separate and dissociable processes.
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Marinovic W, Tresilian JR. Triggering prepared actions by sudden sounds: reassessing the evidence for a single mechanism. Acta Physiol (Oxf) 2016; 217:13-32. [PMID: 26548462 DOI: 10.1111/apha.12627] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 10/13/2015] [Accepted: 11/02/2015] [Indexed: 12/19/2022]
Abstract
Loud acoustic stimuli can unintentionally elicit volitional acts when a person is in a state of readiness to execute them (the StartReact effect). It has been assumed that the same subcortical pathways and brain regions underlie all instances of the StartReact effect. They are proposed to involve the startle reflex pathways, and the eliciting mechanism is distinct from other ways in which sound can affect the motor system. We present an integrative review which shows that there is no evidence to support these assumptions. We argue that motor command generation for learned, volitional orofacial, laryngeal and distal limb movements is cortical and the StartReact effect for such movements involves transcortical pathways. In contrast, command generation for saccades, locomotor corrections and postural adjustments is subcortical and subcortical pathways are implicated in the StartReact effect for these cases. We conclude that the StartReact effect is not a special phenomenon mediated by startle reflex pathways, but rather is a particular manifestation of the excitatory effects of intense stimulation on the central nervous system.
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Affiliation(s)
- W. Marinovic
- School of Health & Rehabilitation Sciences; The University of Queensland; Brisbane Qld Australia
- Centre for Sensorimotor Performance; School of Human Movement and Nutrition Sciences; The University of Queensland; Brisbane Qld Australia
| | - J. R. Tresilian
- Department of Psychology; University of Warwick; Coventry UK
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