Modeling Sensorimotor Learning In Striatal Projection Neurons

Abstract

INTRODUCTION Midbrain dopamine neurons are activated by unpredicted rewards and reward-predicting stimuli, are not influenced by fully predicted rewards, and are depressed by omitted rewards. Thus, they appear to report an error in the prediction of reward (Montague et al. 1996). Reinforcement models have shown that dopamine responses could be used as predictive reinforcement for learning sensorimotor associations (Suri and Schultz 1998). A substrate of such sensorimotor learning may be changes at corticostriatal synapses of striatal medium spiny neurons (Houk et al. 1995). Limbic cortex Neocortex SNr or entopeduncular nucleus (GPi) to 'pre-motor' areas and thalamus Sensorimotor striatum Limbic striatum (predictions) primary reward dopamine neurons (reward prediction errors) sensory stimuli Reward prediction errors signaled by dopamine neuron activity teach the sensorimotor striatum Previous models suggested that reward predictions are computed in th