Functional role of sensory inputs to the motor cortex

The functional role of sensory input to the motor cortex was studied by interrupting two major input pathways. One was the dorsal column, which sends the input directly through the thalamus to the motor cortex, and the other was the sensory cortex, which transfers its input through association fibers. Removal of the sensory cortex produced very little motor disturbances and the function recovered within a week. Section of the dorsal column produced some motor deficit, but the deficit was not severe and the animals recovered nearly completely within 2 wk. Combination of dorsal column section and sensory cortex removal produced severe motor deficits. These consisted of loss of orientation within extrapersonal space and loss of dexterity of individual fingers. These deficits never recovered within the duration of observation, which lasted 4-5 wk. It is concluded that the direct sensory input from the thalamus plays an important role in the control of voluntary movements, but loss of its function can be compensated by the input from the sensory cortex. The possible neuronal basis for the observed motor deficits is discussed and it is proposed that the sensory input functions by selectively changing the excitability of cortical efferent zones before and during the execution of voluntary movements. Recovery of motor function following dorsal column section occurred in parallel with the recovery of sensory input to the motor cortex. The recovered function and sensory input disappeared again following section of the association fibers from the sensory cortex. Neuronal mechanism for this observation is also discussed.

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Paper 22: Experimental Studies on the Role of the Basal Ganglia in the Control of Movement

Proceedings of the Institution of Mechanical Engineers Conference Proceedings ◽

10.1243/pime_conf_1968_183_190_02 ◽

1968 ◽

Vol 183 (10) ◽

pp. 126-134

Author(s):

E. M. Sedgwick

Keyword(s):

Basal Ganglia ◽

Motor Cortex ◽

Caudate Nucleus ◽

Reticular Formation ◽

Sensory Input ◽

Inferior Olive ◽

Experimental Studies ◽

Sensory Inputs ◽

Influence Activity

When the basal ganglia are damaged by disease processes in man, various disorders of movement occur. In order to control movement the basal ganglia must have a sensory input and in the absence of direct connections to motoneurones or motor cortex they must act through intermediate structures. The experiments, on cats, demonstrate: (1) which sensory inputs reach the caudate nucleus and how they influence activity of the neurones there; (2) the effect of the output from the caudate nucleus and globus pallidus on the neurones of the inferior olive and reticular formation. The results are discussed with respect to the control of movement.

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Superior Colliculus Control of Vibrissa Movements

Journal of Neurophysiology ◽

10.1152/jn.90478.2008 ◽

2008 ◽

Vol 100 (3) ◽

pp. 1245-1254 ◽

Cited By ~ 34

Author(s):

Marie E. Hemelt ◽

Asaf Keller

Keyword(s):

Motor Cortex ◽

Superior Colliculus ◽

Sensory Input ◽

Field Potential ◽

Sensory Stimulation ◽

Set Point ◽

Sensory Inputs ◽

Mystacial Vibrissae ◽

Stimulation Of

This study tested the role of the superior colliculus in generating movements of the mystacial vibrissae—whisking. First, we compared the kinematics of whisking generated by the superior colliculus with those generated by the motor cortex. We found that in anesthetized rats, microstimulation of the colliculus evoked a sustained vibrissa protraction, whereas stimulation of motor cortex produced rhythmic protractions. Movements generated by the superior colliculus are independent of motor cortex and can be evoked at lower thresholds and shorter latencies than those generated by the motor cortex. Next we tested the hypothesis that the colliculus is acting as a simple reflex loop with the neurons that drive vibrissa movement receiving sensory input evoked by vibrissa contacts. We found that most tecto-facial neurons do not receive sensory input. Not only did these neurons not spike in response to sensory stimulation, but field potential analysis revealed that subthreshold sensory inputs do not overlap spatially with tecto-facial neurons. Together these findings suggest that the superior colliculus plays a pivotal role in vibrissa movement—regulating vibrissa set point and whisk amplitude—but does not function as a simple reflex loop. With the motor cortex controlling the whisking frequency, the superior colliculus control of set point and amplitude would account for the main parameters of voluntary whisking.

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Time-dependent functional role of the contralesional motor cortex after stroke

NeuroImage Clinical ◽

10.1016/j.nicl.2017.07.024 ◽

2017 ◽

Vol 16 ◽

pp. 165-174 ◽

Cited By ~ 16

Author(s):

L.J. Volz ◽

M. Vollmer ◽

J. Michely ◽

G.R. Fink ◽

J.C. Rothwell ◽

...

Keyword(s):

Motor Cortex ◽

Functional Role ◽

Time Dependent

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The functional role of the ipsilateral motor cortex for motor sequence learning in the elder

Brain Stimulation ◽

10.1016/j.brs.2008.06.129 ◽

2008 ◽

Vol 1 (3) ◽

pp. 288

Author(s):

M. Zimerman ◽

M. Nitsch ◽

L.G. Cohen ◽

C. Gerloff ◽

F. Hummel

Keyword(s):

Motor Cortex ◽

Sequence Learning ◽

Functional Role ◽

Motor Sequence Learning ◽

Motor Sequence

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Whatever next? Predictive brains, situated agents, and the future of cognitive science

Behavioral and Brain Sciences ◽

10.1017/s0140525x12000477 ◽

2013 ◽

Vol 36 (3) ◽

pp. 181-204 ◽

Cited By ~ 1630

Author(s):

Andy Clark

Keyword(s):

Prediction Error ◽

Functional Role ◽

Perception And Action ◽

Cortical Processing ◽

Top Down ◽

Special Contribution ◽

Sensory Inputs ◽

Target Article ◽

Science Of Mind

AbstractBrains, it has recently been argued, are essentially prediction machines. They are bundles of cells that support perception and action by constantly attempting to match incoming sensory inputs with top-down expectations or predictions. This is achieved using a hierarchical generative model that aims to minimize prediction error within a bidirectional cascade of cortical processing. Such accounts offer a unifying model of perception and action, illuminate the functional role of attention, and may neatly capture the special contribution of cortical processing to adaptive success. This target article critically examines this “hierarchical prediction machine” approach, concluding that it offers the best clue yet to the shape of a unified science of mind and action. Sections 1 and 2 lay out the key elements and implications of the approach. Section 3 explores a variety of pitfalls and challenges, spanning the evidential, the methodological, and the more properly conceptual. The paper ends (sections 4 and 5) by asking how such approaches might impact our more general vision of mind, experience, and agency.

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