Note that, insofar as the dACC takes account of control-relevant outcome information in estimating EVC, it should therefore predict subsequent shifts in control based on such information. There is robust evidence for such a link, as will be discussed below. Reward-Prediction Error Signals. As articulated in Equation 2, the value term in the EVC expression refers not only to the immediate reward associated with an outcome, but also to the expected future reward. This is important, because it allows control-signal specification to be based on delayed outcomes. Readers familiar with reinforcement

learning will recognize this particular formulation of value from that context ( Sutton and Barto, 1998). In reinforcement learning models, estimates learn more of state value are typically shaped not directly by raw representations of reward, but instead by reward-prediction errors (PE), signals indicating the extent to which experienced outcomes are

better or worse than expected. A number of findings indicate the occurrence of PE signals in the dACC. The earliest evidence came from EEG recordings demonstrating an event related potential (ERP) with a frontomedial source that occurs in response PLX-4720 research buy to negative outcomes. This was dubbed the feedback-related negativity (FRN; Miltner et al., 1997), referring to its occurrence in response to negative feedback such as the indication of an error in task performance or a monetary loss following a gamble (Gehring and Willoughby, 2002). Critically, the FRN has been found to be sensitive to the expectations established by

local context (Holroyd et al., 2004a, Jessup et al., 2010 and Nieuwenhuis et al., 2005b). For example, in a gambling task, when the range of outcomes is from negative to neutral, the FRN is observed for losses but not neutral outcomes. However, when outcomes range from neutral to positive, the FRN is now observed for neutral outcomes, but not gains. Thus, expectations established by context dictate whether the FRN is elicited by a neutral outcome (see also Jessup et al., 2010). This provides strong evidence that the FRN reflects Adenylyl cyclase a PE, rather than a direct representation of absolute reward. Although the source of the FRN has not been definitively localized to dACC, neuroimaging studies have demonstrated activity in dACC under conditions that mimic those in which the FRN is observed (Holroyd et al., 2004b). The FRN is closely related to another commonly observed ERP, the error related negativity (ERN). This occurs following errors in speeded response trials even when explicit feedback is not provided. There is direct evidence that the ERN has its source in the dACC: Simultaneous recording of EEG and fMRI has shown that the magnitude of the ERN correlates with the BOLD signal from dACC on a trial-by-trial basis (Debener et al., 2005).