Resting autonomic activity predicts the efficiency of approach-avoidance responses to emotional faces

In social situations, adaptive responses to another are crucial for smooth interactions, requiring immediate actions based on contextual cues. While previous studies have demonstrated the importance of autonomic nervous system (ANS) in emotional processing, the relationship between resting ANS activity and approach-avoidance responses to emotional faces remains unclear. This study investigated how resting autonomic nervous activity measured by skin conductance level (SCL) relates to approach-avoidance decisions in response to facial expressions. After recording resting SCL, participants performed an approach-avoidance task (AAT) with emotional facial stimuli. The task required either approaching happy faces while avoiding angry faces (value-congruent condition) or the opposite pattern (value-incongruent condition). Reaction times (RTs) were significantly faster in value-congruent conditions compared to value-incongruent conditions. The resting SCL showed a significant correlation with the congruency effect (RT difference between conditions). These findings suggest that resting autonomic states, particularly sympathetic arousal, may contribute to the efficiency of approach-avoidance responses. Higher sympathetic activity at rest predicted more efficient responses to emotional faces, potentially reflecting enhanced action readiness. These results extend previous findings on ANS involvement in emotional processing to the domain of approach-avoidance responses to social stimuli, highlighting the role of physiological states in adaptive social behaviour.