Emotional Valence Modulates Low Beta Suppression and Recognition of Social Interactions

摘要

Emotional valence may have evolutionary adaptive purposes as negative stimuli can be related to survival against threat and positive stimuli to facilitating relationships. This can be seen in the different impact positive and negative stimuli have on human health and well-being, and in the valence-specific cortical activity and neurophysiological patterns reported; for example, negative stimuli are processed more rapidly than positive. Valence-specific patterns are affected by individual differences and personality traits such as empathy, where levels of empathy relate to different reactivity patterns to valence. Here we investigated the effect of valence on neurophysiological responses and interpretation of social interactions depicted by point-light biological motion (PLBM) displays. The meaning of each PLBM display is revealed as the sequence unfolds and is therefore not readily available for snap assessments such as fight or flight responses. We compared electroencephalogram (EEG) reactivity during observation of the displays between individuals with low, moderate, or high levels of empathy. Results indicated that positive displays induced significantly larger suppression in lower beta (13-20 Hz) compared to control displays, while negative displays revealed no difference in suppression compared to scrambled versions. However, no difference between positive and negative displays was observed, suggesting that the rapid processing of negative displays may have been minimized by revealing meaning more slowly. Positive displays were interpreted more accurately, while levels of empathy did not modulate either neurophysiological responses or interpretation, suggesting that empathy under these conditions did not influence the way in which valence was processed or interpreted.