Dissociable responses to punishment in distinct striatal regions during reversal learning

Adaptive behavior depends on the ability to flexibly alter our choices in response to changes in reward and punishment contingencies. One brain region frequently implicated in such behavior is the striatum. However, this region is functionally diverse and there are a number of apparent inconsistencies across previous studies. For instance, how can significant BOLD responses in the ventral striatum during punishment-based reversal learning be reconciled with the frequently demonstrated role of the ventral striatum in reward processing? Here we attempt to address this question by separately examining BOLD responses during reversal learning driven by reward and during reversal learning driven by punishment. We demonstrate simultaneous valence-specific and valence-nonspecific signals in the striatum, with the posterior dorsal striatum responding only to unexpected reward, and the anterior ventral striatum responding to both unexpected punishment as well as unexpected reward. These data help to reconcile conflicting findings from previous studies by showing that distinct regions of the striatum exhibit dissociable responses to punishment during reversal learning.