The purpose of this present paper is not to give a detailed critique of the extant theories of ACC function, particularly with regard to the human electrophysiological literature, as this has been accomplished comprehensively by several recent reviews (Botvinick, Braver, Barch, Carter and Cohen, 2001; Holroyd and Coles, 2002; Paus, 2001; Ridderinkhof, Ullsperger, Crone and Nieuwenhuis, 2004; Rushworth, Walton, Kennerley and Bannerman, 2004). Instead, we wish to discuss how recent work investigating decision making, where the relationships between actions and their consequences do not remain fixed, has illuminated one aspect of the function of the ACC. By forcing subjects to use their recent experience to select an appropriate course of action, these studies uncover a crucial role for the ACC, particularly the dorsal sulcal region (see Figure 1), in forming action-outcome associations to guide response selection.
