Section: New Results

The formation of habits

Concerning action aspects of loops, we made important extensions to a model of basal ganglia that we developed recently [54] in interaction with another team in our neuroscience lab. In addition to extending the bio-plausibility of this model with an implementation at the spiking level, we have also developed this year a new theoretical framework that provides a novel explanation for the formation and the expression of habits in the cortex of primates by considering the basal ganglia as an implicit supervisor. This has been achieved with a model of basal ganglia running both at the rate and spiking levels. This framework predicts that Hebbian learning and reinforcement learning can be explicitly dissociated by inactivating the output of the basal ganglia during learning and later tested in normal conditions. Experimental results in the monkey confirmed this prediction and explain how a behavioral decision results from both the cooperation (acquisition) and competition (expression) of two distinct but entangled memory systems.