Abstract
Background and Objectives: Research has suggested that individual differences in Behavioral Inhibition System (BIS) and the Behavioral Activation System (BAS) are related to positive and negative affects in asymmetrical brain regions. This study aimed to investigate the effect of BIS/BAS differences on brain oscillation in response to neutral, positive and negative stimuli.
Materials and Methods: In this study EEG was recorded in 36 undergraduate students (18 individuals with high BAS sensitivity, comprising 18 individuals with high BIS sensitivity) during viewing affective pictures. In each cases artifact-free EEG epochs were transformed to frequency domain by means of the Fast Fourier Transformation (FFT) algorithm. Absolute power mean of alpha band (8-12 Hz) of the interior and posterior areas was calculated for each participant.
Results: Results revealed an increased response to neutral stimuli in BAS group within the left frontal and left parietal areas. No significant effect was found in BIS group in this condition. Left frontal activity for positive stimuli and right frontal activity for negative stimuli were found in the BAS and BIS group, respectively. Predicted effects for BAS and BIS with in posterior regions were not significant.
Conclusion: These findings are consistent with the hypothesis of brain regions to positive and negative affect in frontal areas, but this pattern does not exist in the posterior areas.