A model arm for testing motor control theories on corrective movements during reaching

2007 ◽  
pp. 986-989
Author(s):  
Stefano Ramat ◽  
D. Curone ◽  
F. Lunghi ◽  
G. Magenes
Keyword(s):  
Motor Control ◽  
Control Theories

Motor Control Theories — Insights for therapists

Physiotherapy ◽  
1997 ◽  
Vol 83 (8) ◽  
pp. 397-405 ◽  
Author(s):  
Patricia Bate
Keyword(s):  
Motor Control ◽  
Control Theories

scholarly journals Evolution of Motor Control: From Reflexes and Motor Programs to the Equilibrium-Point Hypothesis

2008 ◽  
Vol 19 (1) ◽  
pp. 3-24 ◽  
Author(s):  
Mark Latash
Keyword(s):  
Motor Control ◽  
Equilibrium Point ◽  
Voluntary Movements ◽  
Motor Programs ◽  
Equilibrium Point Hypothesis ◽  
Motor Synergies ◽  
Recent Developments ◽  
Active Motor ◽  
Control Theories

Evolution of Motor Control: From Reflexes and Motor Programs to the Equilibrium-Point HypothesisThis brief review analyzes the evolution of motor control theories along two lines that emphasize active (motor programs) and reactive (reflexes) features of voluntary movements. It suggests that the only contemporary hypothesis that integrates both approaches in a fruitful way is the equilibrium-point hypothesis. Physical, physiological, and behavioral foundations of the EP-hypothesis are considered as well as relations between the EP-hypothesis and the recent developments of the notion of motor synergies. The paper ends with a brief review of the criticisms of the EP-hypothesis and challenges that the hypothesis faces at this time.

scholarly journals Functional connectivity between the cerebellum and somatosensory areas implements the attenuation of self-generated touch

2019 ◽  
Author(s):  
Konstantina Kilteni ◽  
H. Henrik Ehrsson
Keyword(s):  
Magnetic Resonance Imaging ◽  
Motor Control ◽  
Magnetic Resonance ◽  
Functional Connectivity ◽  
Functional Magnetic Resonance Imaging ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Neural Basis ◽  
Somatosensory Areas ◽  
Control Theories

AbstractSince the early 1970s, numerous behavioral studies have shown that self-generated touch feels less intense than the same touch applied externally. Computational motor control theories have suggested that cerebellar internal models predict the somatosensory consequences of our movements and that these predictions attenuate the perception of the actual touch. Despite this influential theoretical framework, little is known about the neural basis of this predictive attenuation. This is due to the limited number of neuroimaging studies, the presence of conflicting results about the role and the location of cerebellar activity, and the lack of behavioral measures accompanying the neural findings. Here, we combined psychophysics with functional magnetic resonance imaging to detect the neural processes underlying somatosensory attenuation in male and female healthy human participants. Activity in bilateral secondary somatosensory areas was attenuated when the touch was presented during a self-generated movement (self-generated touch) than in the absence of movement (external touch). An additional attenuation effect was observed in the cerebellum that is ipsilateral to the passive limb receiving the touch. Importantly, we further found that the degree of functional connectivity between the ipsilateral cerebellum and the contralateral primary and bilateral secondary somatosensory areas was linearly and positively related to the degree of behaviorally assessed attenuation; that is, the more participants perceptually attenuated their self-generated touches, the stronger this corticocerebellar coupling. Collectively, these results suggest that the ipsilateral cerebellum is fundamental in predicting self-generated touch and that this structure implements somatosensory attenuation via its functional connectivity with somatosensory areas.Significance statementWhen we touch our hand with the other, the resulting sensation feels less intense than when another person or a machine touches our hand with the same intensity. Early computational motor control theories have proposed that the cerebellum predicts and cancels the sensory consequences of our movements; however, the neural correlates of this cancelation remain unknown. By means of functional magnetic resonance imaging, we show that the more participants attenuate the perception of their self-generated touch, the stronger the functional connectivity between the cerebellum and the somatosensory cortical areas. This provides conclusive evidence about the role of the cerebellum in predicting the sensory feedback of our movements and in attenuating the associated percepts via its connections to early somatosensory areas.

scholarly journals Gauging Gait Disorders with a Method Inspired by Motor Control Theories: A Pilot Study in Friedreich’s Ataxia

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1144
Author(s):  
Arnaud Gouelle ◽  
Samantha Norman ◽  
Bryanna Sharot ◽  
Stephanie Salabarria ◽  
Sub Subramony ◽  
...  
Keyword(s):  
Motor Control ◽  
Gait Analysis ◽  
Outcome Measures ◽  
Outcome Measure ◽  
Dynamic Instability ◽  
Friedreich’S Ataxia ◽  
Friedreich's Ataxia ◽  
Assistive Device ◽  
Sample Population ◽  
Control Theories

To date, it has been challenging for clinicians and researchers alike to use the multiple outcome measures available to create a meaningful clinical picture and perform effective longitudinal follow-up. It has been found that instrumented gait analysis can provide information associated with a patient’s performance and help to remedy the shortcomings of the currently available outcome measures. The goal of this methodological article is to set the background and justify a new outcome measure inspired by the motor control theories to analyze gait using spatiotemporal parameters. The method is applied in a population of individuals living with Friedreich’s ataxia (FRDA), a neurodegenerative disease. The sample population consisted of 19 subjects, 11 to 65 years of age with FRDA, who either ambulated independently, with a cane, or with a rollator. Three scores based on the distance from healthy normative data were used: Organization Score, Variability Score, and an overall measurement, the Global Ambulation Score. The scores were then compared to the Scale for Assessment and Rating of Ataxia (SARA) Gait Score (SARA-GS), a clinical scale currently being used for gait analysis in FRDA. Organization Scores demonstrated a longitudinal deterioration in the gait characteristics from independent ambulators to those who ambulated with a rollator. Variability Scores mostly reflected dynamic instability, which became greater as the requirement of an ambulation aid or the switch from a cane to a rollator was imminent. The global value given by the Global Ambulation Score, which takes into consideration both the Organization Score, the Variability Score, and the level of assistive device, demonstrated a logarithmic relationship with the SARA-GS. Overall, these results highlight that both components introduced should be analyzed concurrently and suggest that the Global Ambulation Score may be a valuable outcome measure for longitudinal disease progression.

scholarly journals Action enhances predicted touch

2020 ◽  
Author(s):  
Emily R. Thomas ◽  
Daniel Yon ◽  
Floris P. de Lange ◽  
Clare Press
Keyword(s):  
Motor Control ◽  
Computational Modelling ◽  
Tactile Perception ◽  
Central Tenet ◽  
Predictive Mechanisms ◽  
Control Theories ◽  
Clinical Populations

AbstractIt is widely believed that predicted tactile action outcomes are perceptually attenuated. The present experiments determined whether predictive mechanisms always generate attenuation, or instead can enhance perception – as typically observed in sensory cognition domains outside of action. We manipulated probabilistic expectations in a paradigm often used to demonstrate tactile attenuation. Participants produced actions and subsequently rated the intensity of forces on a passive finger. Experiment 1 confirmed previous findings that action outcomes are perceived less intensely than passive stimulation, but demonstrated more intense perception when active finger stimulation was removed. Experiments 2 and 3 manipulated prediction explicitly and found that expected touch during action is perceived more intensely than unexpected touch. Computational modelling suggested that expectations increase the gain afforded to expected tactile signals. These findings challenge a central tenet of prominent motor control theories and demonstrate that sensorimotor predictions do not exhibit a qualitatively distinct influence on tactile perception.Statement of RelevancePerception of expected action outcomes is thought to be attenuated. Such a mechanism may be adaptive because surprising inputs are more useful - e.g., signalling the need to take new courses of action - and is thought to explain why we cannot tickle ourselves and unusual aspects of action and awareness in clinical populations. However, theories outside of action purport that predicted events are perceptually facilitated, allowing us to generate largely accurate representations of our noisy sensory world. We do not know whether action predictions really alter perception differently from other predictions because different manipulations have been performed. Here we perform similar manipulations and demonstrate that action predictions can enhance, rather than attenuate, touch. We thereby demonstrate that action predictions may not have a qualitatively distinct influence on perception, such that we must re-examine theories concerning how predictions influence perception across domains and clinical theories based upon their assumptions.

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