basal ganglia Flashcards
general role of basal ganglia
inhibiting and initiating movements, reward expectations and decisions
- gating proper initiation of movement
cerebellum
little brain
coordination of ongoing movements
important functions of BG
- activates appropriate movements
- suppress inappropriate movements
- critical for sequential actions
- neural models for movement and action selection, particularly for guiding actions based on past reward (goal-directed behaviour)
major inputs to the basal ganglia are from
- nearly the entire cerebrum (cognitive, limbic, sensory, motor)
- thalamus
- amygdala (fear, desire)
- hippocampus (spatial location, memory)
treatment of motor impariment
- L-dopa to increase dopamine levels
- stimulate basal ganglia or thalamus (deep brain stimulation)
worse than expected
if the fish is awful, dopamine neurons pause causing LTD on the fish neurons
- input to fish striatal neurons are weakened (via LTD) so next time steak neurons have larger input and wins the competition and steak is chosen
better than expected
if the fish was great, dopamine neurons fire inducing LTP
- input to fish striatal neurons are strengthened (via LTP) so next time fish neurons have even larger input and wins the competition and fish is chosen
reinforcement learning
learning from reward outcomes
- relies of difference between expected and actual reward outcome to compute the value of actions or states