An examination of how reward associations differentially facilitate and impair Stroop performance

Behavioral performance is improved when the color of a Stroop stimulus is tied to a potential reward but is impaired when the irrelevant word meaning is reward related. The facilitation (reward responsiveness) and impairment (modulation of interference of reward association; MIRA) are different cognitive processes. In this study, we explored whether reward responsiveness and MIRA were subject to: 1) the reward magnitude, 2) whether stimulus-reward color instructions were provided, 3) the certainty of the stimulus reward contingency, 4) whether the influence of reward on Stroop performance continued following reward discontinuation, and 5) the dispositional approach motivation of the participant. Results from a high-powered online study (N = 205) suggest that large, versus small, reward colors increased reward responsiveness before and after reward discontinuation but relatively greater impairment by a large reward related word was only observed following reward discontinuation. Stimulus-reward colorinformation allowed participants to respond faster to obtain larger reward, especially when the stimulus-reward contingency was uncertain, but did not influence the impairment by reward related words. Individuals who were highly reward responsive, as indicated by their behavioral activation system (BAS) scale scores, were faster to respond to obtain a large reward when provided stimulus reward color instructions but were equally impaired by large reward related words as low reward responsive individuals. Results suggest that reward responsiveness was influenced by motivation whereby stimulus-reward information and higher BAS was associated with greater reward responsiveness. In contrast, MIRA, like other forms of reward-based distraction, was not influenced by motivation or reward responsiveness.