The effect of positive and negative affect induction on frontal and posterior asymmetry of alpha brain waves in individuals with high and low brain behavioral systems

brain behavioral systems are related to avoidance and approach behavior. In the model of frontal asymmetry, Davidson introduced avoidance and approach systems. The aim of this study was to investigate The effect of affect induction on frontal and posterior asymmetry of alpha brain waves in individuals with high and low behavioral activation/inhibition systems.

In this regard, 300 non-disordered adults self-reported behavioral inhibition/activation systems questionnaire. After that, based on the Z scores in BAS/BIS scale, four groups (n=28, n=7 in each group) were selected. Quantitative electroencephalography was recorded for each individual in baseline, positive and negative affect induction. Absolute power of alpha waves in four regions and frontal and posterior asymmetries were calculated for each individual. Paired t-test and repeated Measures ANOVA were performed for statistical analysis.

In baseline condition, the high inhibition group showed frontal asymmetry (greater arousal in the F4 region) at the level of P =0.04. In terms of pleasant affect induction, the high and low activation groups showed frontal asymmetry at the level of P <0.01 (more arousal in F3 region). In terms of negative affect induction, the high inhibition group showed frontal asymmetry at the level of P =0.001 (more arousal in the F4 region), and the low activation group showed posterior asymmetry at the level of P = 0.002 (more arousal in the O2 region).

The findings confirm the Gray theory and Davidson model for the frontal asymmetry. Type of induced affect and personality differences Leads to different patterns of asymmetry.