Neuroscience Research //
Cognitive Neuroscience of Reward
The electroencephalographic (EEG) response known as the Reward Positivity (RewP) is a promising candidate biomarker of diminished valuation in anhedonia. The RewP is only elicited by the presentation of a rewarding outcome and it scales with the central feature of reinforcement learning models, the positive reward prediction error (+RPE). Thus, the RewP is specific and sensitive to +RPE, fulfilling the stringent criteria of being an invariant neural marker of this computational process. Importantly, the RewP is boosted by appetitive states and is diminished in depressed individuals, indicating that emotional processes influence this marker of reward learning. While prior work has effectively described these correlations (e.g. Foti and Hajcak, 2009), we do not know how emotion (e.g. depression) and +RPE interact to influence valuation. The objective of this project is to test whether mood directly diminishes +RPE coding in the RewP, or if these are separable influences on this signal. The aim of this arm of the study is to determine if anhedonia and +RPE have independent or interactive influences on the source-level generators underlying the RewP.