Neural activity related to temporal credit assignment in medial prefrontal cortex and secondary motor cortex

Abstract

The neural basis of temporal credit assignment is not well known. To investigate neural processes related to temporal credit assignment in the frontal cortex, I recorded neuronal activity in the dorsal anterior Cingulate cortex, prelimbic cortex, infralimbic cortex and secondary motor cortex of rats performing a dynamic two-armed bandit task in which a choice must be remembered until its outcome is revealed for correct credit assignment. Ifound that choice signals were maintained above the chance level until choice outcome was revealed in all recorded areas. I also found that neural signals for choice, outcome and action value converge when choice outcome was revealed. These results suggest that the frontal cortex maintains choice signals and updates action value by combining the maintained choice signals with action value and outcome signals.