The Influence of Valence on Action Control: A Comparison of Simon Effects in the Extrinsic Affective Simon Task (EAST) and the Spatial Simon Task

Abstract

People adjust their thoughts and actions in response to a changing environment every day and emotions may influence these actions. Understanding how emotion impacts action control in situations where emotion is central to the action (task-relevant) compared to when it is present in the environment as distracting information (task-irrelevant) is essential. Currently it is unclear when emotion most significantly modulates action control. This study seeks to compare how valence (positive versus negative emotion) impacts action control performance when valence is task-relevant and task-irrelevant by using two modified versions of the Simon conflict task. The Simon task is a paradigm to study response conflict by creating interference between a presented stimulus and a subsequent action response. Participants are instructed to respond to a lateralized stimulus on the screen. When the location of the stimulus conflicts with the trained response, this slows reaction times and reduces accuracy compared to when they do not conflict (Simon effect). We created two modified versions of the Simon task and used happy and angry faces as valenced task stimuli. The spatial affective Simon task (ST), participants were instructed to respond to the emotional expression of a face (valence is task-relevant). In the extrinsic affective Simon task (EAST), the affective stimulus was a face with an emotional expression, but participants were instructed to respond to the color of the face (valence is task-irrelevant). We collected reaction times and accuracy rates for each task in 12 healthy participants. Valence did not significantly impact the Simon effect in either task and we did not find a significant Simon conflict effect in the EAST. However, the spatial task did show a significant conflict effect with slower and less accurate responses on conflict trials. Future studies will test alternative modifications to this paradigm’s design to study how emotion could play a role in action control and motor response. Such knowledge will allow these tasks to be translated in clinical research in studying specific brain regions and their role in processing emotional stimuli in conflict response settings