The Change of Cortical Activity Induced by Visual Disgust Stimulus

Jung, Wook; Park, Doo Heum; Yu, Jae Hak; Ryu, Seung Ho; Ha, Ji Hyeon; Shin, Byoung Hak

Abstract

OBJECTIVES
There are a lot of studies that analyze the interaction between the emotion of disgust and the functional brain images using fMRI and PET. But studies using sLORETA (standardized low resolution brain electromagnetic tomography) almost do not exist. The aim of this research is to explore the relationship of the emotion of disgust and the cortical activation using sLORETA analysis.
METHODS
Forty five healthy young adults (27.1+/-2.6 years) participated in the study. While they were watching 4 neutral images and 4 disgusting images associated with mutilation selected from the international affective picture system (IAPS), participants' EEGs were taken for 30 seconds per one picture. Through these obtained EEG data, sLORETA analysis was performed to compare EEGs associated with neutral and negative images.
RESULTS
During looking for visual disgusting stimulus, all participants reported unpleasantness, arousal and stress. In sLORETA analysis, the decrease of current density in theta wave was shown at left frontal superior gyrus (BA10) and middle gyrus (BA10, 11). This voxel cluster consists of a total of 11 voxels and the threshold of t value indicating statistically significant decreases in the current density (p<0.05) was -1.984. There were no differences between male and female in the degree of being disgusted by the stimuli.
CONCLUSION
This finding may suggest that the activation of dorsolateral prefrontal cortex might be associated with regulating disgust emotion.