Reinforcement learning in populations of spiking neurons

Population coding is widely regarded as an important mechanism for achieving reliable behavioral responses despite neuronal variability. However, standard reinforcement learning slows down with increasing population size, as the global reward signal becomes less and less related to the performance of any single neuron. We found that learning speeds up with increasing population size if, in addition to global reward, feedback about the population response modulates synaptic plasticity. (C) 2009 Nature America, Inc. All rights reserved.