7-1 Flashcards
(19 cards)
Three Principles of Sensorimotor Function
- Hierarchical Organization
- Motor output is guided by sensory input.
- Learning changes the nature and locus of sensorimotor control.
Hierarchical Organization
Association cortex at the highest level, muscles at the lowest
2 Sensorimotor AssociationCortex
- Posterior Parietal Association Cortex
- Dorsolateral Prefrontal Association Cortex
Posterior Parietal Association Cortex: Integrates Information about
- Body part location
- Spatial relation with external objects
Posterior Parietal Association Cortex: Receives input from
Visual, Auditory, and Somatosensory systems
Posterior Parietal Association Cortex: Output to
the Association and Secondary Motor Cortices
- Including dorsolateral prefrontal association cortex, secondary motor cortex, and frontal eye field
The planning of movement
- Posterior parietal cortex
- Premotor cortex
- Supplementary motor area
- cerebellum
Posterior parietal cortex
One of the first areas to become active in planning a movement. Keeps track of the position of the body relative to the environment. When surgeons stimulate parts of the posterior parietal cortex during surgery, patients report an intention to move.
Damage to the Posterior Parietal Cortex
- Apraxia
- Contralateral neglect
Contralateral neglect:
inability to respond to stimuli contralateral to the side of the lesion; usually seen with large lesions on the right
Apraxia:
disorder of voluntary movement; problem only evident when instructed to perform an action; usually a consequence of damage to the area on the left
Dorsolateral Prefrontal Association Cortex: input from
Posterior Parietal Cortex
Dorsolateral Prefrontal Association Cortex: output from
Secondary Motor Cortex, Primary Motor Cortex, and Frontal Eye Field
Dorsolateral Prefrontal Association Cortex
evaluates external stimuli and initiates voluntary reactions
Supplementary motor area
Organizes rapid sequence of movements in a specific order; inhibitory if necessary
Active seconds before the movement
Cerebellum
Think of the behavior when someone is intoxicated (alcohol): clumsiness, slurred speech, inaccurate eye movements
- Balance and coordination
- Rapid movements requiring aim, timing, and alternating movements
Examples: clapping hands, speaking, sport activities
- Certain aspects of attention, such as the ability to shift attention and attend to visual stimuli
Cerebellum: input
Primary and Secondary Motor Cortices
Brainstem Motor Nuclei
cerebellum: feedback
from Motor Responses
10 Percent of Brain Mass, but More than 50 Percent of Its Neurons
cerebellum
