Hemispheric alpha asymmetry differentiates within-participants social power states: high social power increases and low social power decreases left frontal cortical activity.

Abstract

Social power is linked to approach and withdrawal motivational systems, with frontal alpha asymmetry (FAA) in the electroencephalogram (EEG) potentially reflecting these tendencies. Higher left-frontal activity suggests approach, while lower levels indicate withdrawal. In this study, we used a novel within-subject design to explore how social power affects FAA. Twenty-five participants completed an episodic recall task inducing high or low social power, or a neutral condition, in random order. EEG alpha power (8-12 hz) was measured to calculate FAA indices for frontal and parietal-occipital regions and compared to resting-state asymmetry. Results showed a significant increase in left-hemispheric activity during high social power recall, affecting both frontal and non-frontal regions, compared to low power and control conditions. Low social power was associated with the least left hemispheric activity. These findings highlight strong effects of social power on brain systems related to approach and avoidance but challenge the notion that FAA is confined to frontal regions. The study enhances understanding of the neural mechanisms behind social power and underscores the value of within-subject designs and baseline measurements in studying neural activity related alpha asymmetry and social power.