EEG based Visualization and Analysis of Emotional processing in Major Depressive Disorder

Major Depressive Disorder is one of the principal causes of disability globally. It is characterized by low self-regard and thoughts of hopelessness. This study aims at analyzing the brain activity during emotional processing in depressed patients. Fifteen adults with a HDRS-17 score of greater than 20 participated in the study. EEG was recorded while viewing two categories of IAPS pictures namely, neutral and high valence high arousal. SAM scale was utilized to find the perceptual emotions of the participants. The behavioral study showed a neutral response for both the sets of pictures. The mean relative power of alpha was observed to be elevated in left frontal region indicating negative emotion. Significant changes in mean relative beta power was observed between high valence high arousal stimuli ( $\mathrm{F}3=0.01,\ \mathrm{F}4=0.016,\ \mathrm{F}7=0.013,\ \mathrm{F}8=0.007$ ) and neutral stimuli ( $\mathrm{F}3=0.004,\ \mathrm{F}4=0.005,\ \mathrm{F}7=0.002,\ \mathrm{F}8=0.002$ ), indicating arousal though it is not perceived. Frontal alpha asymmetry scores, with the significance of $\mathrm{p} , showed withdrawal behavior while viewing the pictures when compared to rest. It is concluded that negative emotion for both neutral and positive stimuli could be a characteristic feature for Major Depressive Disorder.