Frontal brain oscillations and social anxiety: a cross-frequency spectral analysis during baseline and speech anticipation.

Increasing evidence suggests that cross-frequency spectral coupling between slow (SW) and fast (FW) wave activity in the EEG supports information exchange between separate and functionally distinct neural systems. Further, evidence suggests that states of uncertainty, anticipation and anxious apprehension involve a high degree of SW-FW coupling. We examined whether adults pre-selected for high and low social anxiety showed distinct patterns of frontal brain oscillatory coupling during resting baseline and the anticipation of a self-presentation task. As predicted, the high socially anxious group showed significantly greater SW-FW coupling than the low socially anxious group, in the right, but not left, frontal electrode sites while anticipating a public speaking task. Additionally, the low socially anxious group showed a decrease in delta power from baseline to speech anticipation, suggesting that they found the same task potentially rewarding. Exploratory analyses indicated no effects of delta-gamma coupling. However, EEG gamma band power increased during the speech anticipation condition, in the parietal electrode sites. Our results are discussed in the context of previous studies on cross-frequency EEG coupling in relation to individual differences in motivation and emotion and future directions for studying the neural correlates of anxiety. Copyright 2009 Elsevier B.V. All rights reserved.