Motor Control, Basal Ganglia, and Cerebellar Computation
Motor systems as predictive controllers
Hierarchical motor organization
Motor behavior emerges from interactions among cortex, basal ganglia, cerebellum, brainstem, spinal cord, and sensory feedback loops. Modern theories emphasize internal models, prediction error, and adaptive calibration rather than simple feedforward command.
Basal ganglia vs cerebellum
Basal ganglia
- Action selection and vigor
- Strong links to reinforcement learning and habit
Cerebellum
- Error correction and timing
- Critical for adaptation and coordination
A lesion of the cerebellum is most likely to cause which deficit?
Cerebellar dysfunction typically impairs coordination, timing, and error correction.
Correct answer: Ataxia and dysmetria
What is dysmetria?
It is a classic sign of cerebellar dysfunction.
Correct answer: The inability to judge distance or range of movement accurately.
Motor learning
Motor learning depends on practice-driven plasticity in sensory-motor loops. Reward prediction error, supervised error signals, and use-dependent changes all contribute, with different systems dominating depending on task structure.
Advanced perspective
Motor control is best studied as a control-theoretic problem in a noisy, partially observed environment.
Name one reason cerebellar circuits are thought to support supervised learning.
Error-based learning is a core cerebellar function.
Correct answer: They can compare intended movement with actual outcome and update future commands based on error.
Which structure is most closely linked to habit formation and action vigor?
Basal ganglia circuits are central to habitual and vigor-related aspects of movement.
Correct answer: Basal ganglia