Skill Memory and Brain Substrates

Flashcards covering brain substrates involved in skill memory, including basal ganglia, cerebellum, and cerebral cortex, as well as clinical perspectives such as Parkinson's disease and motor prostheses.

Perceptual-motor skills

Engage spinal cord and brainstem sensory cortices; somatosensory and visual system especially important.

Basal Ganglia

Receives input from cortical neurons, outputs go to thalamus and brain stem, initiates and maintains movement, controls velocity/direction/amplitude, prepares to move

Disruption of Basal Ganglia

Affects skill learning but not formation/recall of facts; synaptic plasticity enables changes

Maze running skill

Rats with hippocampal damage perform poorly; rats with damage to BG perform normally without cues

T-maze tasks with added cues

Impaired in rats with BG lesions when light cues signal food in certain arms of the maze

Neural activity in BG during T-maze

Some fired when going right/left, some when tone sounded, some when first released, some at end.

Pattern of BG neural responding during learning

Increased neuronal responding at beginning and end, aligned with Fitt's model.

Human BG activity during cognitive skill learning

BG active when learning cognitive skills such as weather prediction task.

Cortical Representations of Skills

Region of brain activation depends on skill; relevant areas expand, irrelevant areas show fewer changes.

Elbert et al. (1995) study

Cortical activation in somatosensory cortex while playing violin more extensive in violinists.

Recanzone et al. (1992) monkey study

Enlarged cortical representations for finger used in the task.

Cerebellum

Important for formation, execution, timing of conditioned responses; basic neural system for skill memories.

Cerebellum role in skills

Plays role in forming memories for skills, especially movement sequences requiring timing.

Cerebellar changes

Seem related to skill learning, not just activity; rats running on wheel don't show these changes.

Leggio et al. (2000) rat study

Lesion to cerebellum before observations impaired observational learning.

Laforce & Doyon (2001) results

Ability to transfer skill impaired for patients with cerebellar damage.

Cerebellum role

Movement sequences with timing, target tracking.

Cerebral cortex role

Controlling complex action sequences.

Basal ganglia role

Linking sensory events to responses.

Parkinson's Disease

Progressive deterioration of motor control; increasing muscular rigidity, tremors, difficulty initiating movements.

Parkinson's Disease cause

Reduction in neurons that control activity in basal ganglia (substantia nigra pars compacta).

Deep brain stimulation

Placed near neurons connecting basal ganglia with cortical circuits; relieves some symptoms.

Motor prostheses

Collect electrical signals from neurons, transmit to computer that signals movement in robotic limb.