Novel rewards occlude the reward positivity, and what to do about it

Both the Reward Positivity (RewP) and the novelty N2 component appear within the same spatio-temporal window. This signal overlap impedes the assessment of the RewP evoked by complex novel rewards like affective or motivational imagery. Here we conducted a series of experiments which successfully isolated signals of reward and novelty through spectral decomposition as well as with experimental manipulations that systematically removed the influence of novelty on the reward-evoking image. Together, these findings help explain the nature of this component overlap and provide methodological and analytic techniques for isolating reward- and novelty-specific computations to complex stimuli.