Frontal EEG Asymmetry Differs between High and Low Trait Anxious Individuals as a Function of Lateralized Vibrotactile Stress

Abstract

Anxiety is an aversive emotional state marked by hyperarousal and cognitive impairments. Studies using Quantitative Electroencephalography (QEEG) have shown asymmetric right frontal and parietotemporal activity at resting baseline in trait anxious subjects. However, there has been a lack of research investigating changes in QEEG asymmetries in trait anxious subjects following stress. The current study aimed to assess changes in QEEG asymmetries following lateralized vibrotactile and affective stress in trait anxious subjects. Following a two-minute baseline, subjects underwent two 2-minute stress periods, during which they were presented with auditory and counterbalanced unilateral vibrotactile stressors, each followed by a two-minute recording period. Subjects were classified as high or low trait anxious based on their scores on the Spielberger Trait Anxiety Inventory. A repeated measures ANOVA revealed significant asymmetry score differences between the high and low anxious groups in the F3/F4 (F(1,32) = 5.30, p < 0.03), and F7/F8 (F(1,32) = 4.20, p < 0.05) electrode pairs as a function of lateralized vibrotactile stress. No significant differences were found between groups in the Fp1/Fp2, C3/C4, P3/P4, and P7/P8 electrode pairs or between trials in any of the electrode pairs for either group. These results replicate previous findings demonstrating differences in EEG frontal asymmetries between subjects scoring high or low in trait anxiety with but do not support the use of changes in asymmetry scores as a marker of acute stress. More work needs to be done regarding EEG frontal asymmetry and acute stress.