Cere and BG extras

Question 1

Comparator in Cerebellum

Answer 1

The ION: it CORRECTS for erroneous movement by comparing the expected state (from deep cerebellar nuclei) with the observed state (from eg. visual and proprioceptive feedback)
Conveys error signal to cerebellar cortex via climbing fibers that synapse on Purkinje cells
Leads to LONG TERM DEPRESSION in parallel fibers ability to excite Purkinje cells

Question 2

Result of Comparison and Error Correction

Answer 2

Prediction for limbs has been updated and New ensemble of Purkinje cells are activated = adaptation of the motor system to new situation
THUS CEREBELLUM acts as ADAPTIVE FEEDFORWARD CONTROLLER