A neuropsychological approach to motor control and imagery

2004 ◽  
Vol 27 (3) ◽  
pp. 419-419
Author(s):  
Barbara Tomasino ◽  
Corrado Corradi-Dell'Acqua ◽  
Alessia Tessari ◽  
Caterina Spiezio ◽  
Raffaella Ida Rumiati

In his article Grush proposes a potentially useful framework for explaining motor control, imagery, and perception. In our commentary we will address two issues that the model does not seem to deal with appropriately: one concerns motor control, and the other, the visual and motor imagery domains. We will consider these two aspects in turn.

Author(s):  
Lauren Swiney

Over the last thirty years the comparator hypothesis has emerged as a prominent account of inner speech pathology. This chapter discusses a number of cognitive accounts broadly derived from this approach, highlighting the existence of two importantly distinct notions of inner speech in the literature; one as a prediction in the absence of sensory input, the other as an act with sensory consequences that are themselves predicted. Under earlier frameworks in which inner speech is described in the context of classic models of motor control, I argue that these two notions may be compatible, providing two routes to inner speech pathology. Under more recent accounts grounded in the architecture of Bayesian predictive processing, I argue that “active inference” approaches to action generation pose serious challenges to the plausibility of the latter notion of inner speech, while providing the former notion with rich explanatory possibilities for inner speech pathology.


2018 ◽  
Vol 120 (2) ◽  
pp. 729-740 ◽  
Author(s):  
Elizabeth J. Woytowicz ◽  
Kelly P. Westlake ◽  
Jill Whitall ◽  
Robert L. Sainburg

Two contrasting views of handedness can be described as 1) complementary dominance, in which each hemisphere is specialized for different aspects of motor control, and 2) global dominance, in which the hemisphere contralateral to the dominant arm is specialized for all aspects of motor control. The present study sought to determine which motor lateralization hypothesis best predicts motor performance during common bilateral task of stabilizing an object (e.g., bread) with one hand while applying forces to the object (e.g., slicing) using the other hand. We designed an experimental equivalent of this task, performed in a virtual environment with the unseen arms supported by frictionless air-sleds. The hands were connected by a spring, and the task was to maintain the position of one hand while moving the other hand to a target. Thus the reaching hand was required to take account of the spring load to make smooth and accurate trajectories, while the stabilizer hand was required to impede the spring load to keep a constant position. Right-handed subjects performed two task sessions (right-hand reach and left-hand stabilize; left-hand reach and right-hand stabilize) with the order of the sessions counterbalanced between groups. Our results indicate a hand by task-component interaction such that the right hand showed straighter reaching performance whereas the left hand showed more stable holding performance. These findings provide support for the complementary dominance hypothesis and suggest that the specializations of each cerebral hemisphere for impedance and dynamic control mechanisms are expressed during bilateral interactive tasks. NEW & NOTEWORTHY We provide evidence for interlimb differences in bilateral coordination of reaching and stabilizing functions, demonstrating an advantage for the dominant and nondominant arms for distinct features of control. These results provide the first evidence for complementary specializations of each limb-hemisphere system for different aspects of control within the context of a complementary bilateral task.


2020 ◽  
Vol 8 (2) ◽  
pp. 262-279
Author(s):  
Nicolas Robin ◽  
Lucette Toussaint ◽  
Eric Joblet ◽  
Emmanuel Roublot ◽  
Guillaume R. Coudevylle

This study compared the effects of motor imagery, feedback, and feedback+imagery interventions on soccer pass performance in non-elite players (intermediate, regional level). Participants were randomly divided into Control, Feedback, Imagery, and Feedback+Imagery groups, within a pre- post- intervention design. The intervention lasted 7 weeks, and the task consisted of passing the ball to a target 20-meters away. In each intervention session, the participants performed 3 blocks of four physical trials. The participants of the Feedback and Feedback+Imagery groups received expert feedback, given by the coach, after each block and then, all the participants realized a mental task (countdown or motor imagery). Results showed that the Feedback+Imagery group had the greatest pre- to post-test improvement compared to the other groups, and highlight the beneficial effect of combining verbal feedback and motor imagery to improve soccer passing accuracy. It is suggested to coaches or physical education teachers to adapt their training by incorporating feedback and imagery.


2017 ◽  
Vol 118 (4) ◽  
pp. 2412-2420 ◽  
Author(s):  
Stephen T. Foldes ◽  
Douglas J. Weber ◽  
Jennifer L. Collinger

After paralysis, the disconnection between the cortex and its peripheral targets leads to neuroplasticity throughout the nervous system. However, it is unclear how chronic paralysis specifically impacts cortical oscillations associated with attempted movement of impaired limbs. We hypothesized that μ- (8–13 Hz) and β- (15–30 Hz) event-related desynchronization (ERD) would be less modulated for individuals with hand paralysis due to cervical spinal cord injury (SCI). To test this, we compared the modulation of ERD from magnetoencephalography (MEG) during attempted and imagined grasping performed by participants with cervical SCI ( n = 12) and able-bodied controls ( n = 13). Seven participants with tetraplegia were able to generate some electromyography (EMG) activity during attempted grasping, whereas the other five were not. The peak and area of ERD were significantly decreased for individuals without volitional muscle activity when they attempted to grasp compared with able-bodied subjects and participants with SCI,with some residual EMG activity. However, no significant differences were found between subject groups during mentally simulated tasks (i.e., motor imagery) where no muscle activity or somatosensory consequences were expected. These findings suggest that individuals who are unable to produce muscle activity are capable of generating ERD when attempting to move, but the characteristics of this ERD are altered. However, for people who maintain volitional muscle activity after SCI, there are no significant differences in ERD characteristics compared with able-bodied controls. These results provide evidence that ERD is dependent on the level of intact muscle activity after SCI. NEW & NOTEWORTHY Source space MEG was used to investigate sensorimotor cortical oscillations in individuals with SCI. This study provides evidence that individuals with cervical SCI exhibit decreased ERD when they attempt to grasp if they are incapable of generating muscle activity. However, there were no significant differences in ERD between paralyzed and able-bodied participants during motor imagery. These results have important implications for the design and evaluation of new therapies, such as motor imagery and neurofeedback interventions.


Author(s):  
Enhua Guo ◽  
Julia Katila ◽  
Jürgen Streeck

This study investigates a variety of ways in which dental clinicians and adult guardians touch child patients to get them to participate in dental procedures in China’s mainland. Children at the dentist’s office often experience pain and show fear, and dental care practitioners as well as adult guardians (in our case, parents and grandparents) perform tactile and haptic actions of comfort and control in response. Our analysis shows the dual roles that the children’s bodies play when touching and being touched in the dentist’s office: At times, they are agents or animators in control of their own movements; at other times, they are objects of manipulation by others. Moreover, sometimes their movements are collaboratively controlled by multiple participants, including the patient him/herself. During intercorporeal engagements in Chinese pediatric dentistry, as in many other contexts of interpersonal touch, the center of control and the source of animation of movements and actions are often distributed among multiple bodies. What is more, tactile and haptic actions in this context shift back and forth between direct forms, where the act of one body causes a change in the other, and actions that can be properly called semiotic or communicative in Grice’s (1968) sense, which aim to make the other person recognize the actor’s intent and act on it of his or her own volition.


1995 ◽  
Vol 73 (5) ◽  
pp. 2120-2122 ◽  
Author(s):  
S. Ma ◽  
A. G. Feldman

1. To address the problem of the coordination of a redundant number of degrees of freedom in motor control, we analyzed the influence of voluntary trunk movements on the arm endpoint trajectory during reaching. 2. Subjects made fast noncorrected planar movements of the right arm from a near to a far target located in the ipsilateral work space at a 45 degrees angle to the sagittal midline of the trunk. These reaching movements were combined with a forward or a backward sagittal motion of the trunk. 3. The direction, positional error, curvature, and velocity profile of the endpoint trajectory remained invariant regardless of trunk movements. Trunk motion preceded endpoint motion by approximately 175 ms, continued during endpoint movement to the target, and outlasted it by 200 ms. This sequence of trunk and arm movements was observed regardless of the direction of the endpoint trajectory (to or from the far target) or trunk movements (forward or backward). 4. Our data imply that reaching movements result from two control synergies: one coordinates trunk and arm movements leaving the position of the endpoint unchanged, and the other produces interjoint coordination shifting the arm endpoint to the target. The use of functionally different synergies may underlie a solution of the redundancy problem.


2021 ◽  
Author(s):  
Justinas Česonis ◽  
David W. Franklin

AbstractThe separation of distinct motor memories by contextual cues is a well known and well studied phenomenon of feedforward human motor control. However, there is no clear evidence of such context-induced separation in feedback control. Here we test both experimentally and computationally if context-dependent switching of feedback controllers is possible in the human motor system. Specifically, we probe visuomotor feedback responses of our human participants in two different tasks – stop and hit – and under two different schedules. The first, blocked schedule, is used to measure the behaviour of stop and hit controllers in isolation, showing that it can only be described by two independent controllers with two different sets of control gains. The second, mixed schedule, is then used to compare how such behaviour evolves when participants regularly switch from one task to the other. Our results support our hypothesis that there is contextual switching of feedback controllers, further extending the accumulating evidence of shared features between feedforward and feedback control.


2021 ◽  
Author(s):  
Shruthi Sukumar ◽  
Reza Shadmehr ◽  
Alaa A Ahmed

During foraging, animals decide how long to stay and harvest reward, and then abandon that site and travel with a certain speed to the next reward opportunity. One aspect of this behavior involves decision-making, while the other involves motor-control. A recent theory posits that control of decision-making and movements may be linked via a desire to maximize a single normative utility: the sum of all rewards acquired, minus all efforts expended, divided by time. If this is the case, then the history of rewards, and not just its immediate availability, should dictate how long one decides to stay and harvest reward, and how slowly one travels to the next opportunity. We tested this theory in a series of experiments in which humans used their hand to harvest tokens at a reward patch, and then used their arm to reach toward a subsequent opportunity. Following a history of poor rewards, people not only foraged for a longer period, but also moved slower to the next reward site. Thus, reward history had a consistent effect on both the decision-making process regarding when to abandon a reward site, and the motor control process regarding how fast to move to the next opportunity.


Author(s):  
Margaret A. Boden

Artificial intelligence (AI) seeks to make computers do the sorts of things that minds can do, which involves psychological skills such as perception, association, prediction, planning, and motor control. Intelligence is a richly structured space of diverse information-processing capacities. Accordingly, AI uses many different techniques, addressing many different tasks. ‘What is Artificial Intelligence?’ explains the two main aims of AI: one being technological and the other scientific. It looks at AI’s influence on the life sciences and philosophy. Can any AI system possess real intelligence, creativity, or life? It also considers how AI began, virtual machines, the major types of AI, and cybernetics.


Sign in / Sign up

Export Citation Format

Share Document