Visuomotor integration of relevant and irrelevant angry and fearful facial expressions

Our brain codes the features of perceptual events in a distributed fashion, raising the question of how information belonging to one event is processed without any interference of features from other events. Hommel (1998) suggested the "event file" concept to elucidate these mechanisms: an episodic memory trace "binding" together perceptual features and actions related to an object. Using a similar paradigm, we designed a pilot experiment and four additional experiments to investigate whether emotion, similarly than perceptual features, could bind with a motor response when the emotion was relevant and irrelevant for the task. Few studies have revealed this to be the case. We investigated how angry and fearful faces expressed by avatars and humans might be subject to a binding phenomenon. Our results show that at least three degrees of visuomotor binding seem to coexist: one implicating the relevant feature of the task with a strong effect on behavior, another implicating the location with a smaller behavioral effect (even if not task related), and a third implicating non-task-related features with behavioral effects only under specific conditions in which emotion could play a role. Our adaptation of Hommel's paradigm showed that emotional percepts can be subject to visuomotor binding effects even if the emotion is not task related confirming the important role of emotional information for the central nervous system. These findings offer new perspective in the investigation of the emotion-action binding at the neuronal level.