Modulation Of Movements By The Cerebellum

Question 1

What is the decorrelation learning rule?

Answer 1

Where a synaptic weight between PF and PC is changed according to the correlation between the parallel-fibre signal and the error signal conveyed by the climbing fibre
Positive correlation = reduce weight
Negative correlation = increase weight

Question 2

When does learning stop in the decorrelation learning rule?

Answer 2

Learning stops when there is no longer a correlation between any parallel-fibre signal and the climbing fibre signal

Question 3

What is the basic circuit in the cerebellar cortex?

Answer 3

Input from mossy fibres which synapse on granule cells whose axons (parallel-fibres) synapse onto Purkinje cells which provide the output of cerebellar cortex. PC also receive climbing fibre inputs

Question 4

What does the circuit do?

Answer 4

Climbing fibres convey an error signal about movement inaccuracy. This adjusts the weights of the synapses between parallel fibres and PC, altering PC output to make movements more accurate.
Evidenced in adaptation of VOR.