Why does the brain contain more than one memory system? Genetic algorithms can play a role in elucidating this question. Here, model animals were constructed containing a dorsal striatal layer that controlled actions, and a ventral striatal layer that controlled a dopaminergic learning signal. Both layers could gain access to three modeled memory…

Extinction of operantly conditioned responses, which provides a measure of the ability to adapt to changes in the reinforcement value of stimuli, has been linked to orbitofrontal cortex (OFC) in human and non-human animals. This article examines the feasibility of using extinction as a measure of the development of OFC function in preschool-age…