Emotional Pictures In Depression Induced By Gamma Wave Activity In Patients With Normal Research

Present study suggested that the gamma showed relatively more power for positivepicture over the left frontal region as compared to the right and a laterality shift towardsthe right frontal for negative picture in control. With ERP and fMRI, studies indicatedthat depressed individuals exhibit cognitive biases in negative information processing.The current study used affective picture identification tasks and examinedGamma-band EEG in response to affective pictures in depression and control. Thirteendepressed and normal people participated in the current study respectively and theywere instructed to view positive, neutral, and negative images freely. As soon as detectpositive pictures, they were required to press a button as quickly and accurately aspossible.Behavioral data showed that the depressed people responded more slowly topositive pictures and the accuracy rate was significantly lower than the healthy control.Gamma-band(30-90Hz) EEG in response to affective pictures in80-130ms,120-200ms,200-300ms and300-450ms following presentation of the stimuli was significantdifference. The gamma showed relatively more power for positive picture over the leftfrontal region as compared to the right in healthy participants. But The gamma showedrelatively more power for positive picture over the left frontal region as compared to theright in depressed participants. The gamma displayed relatively less power for negativepicture over the left frontal region as compared to the right in healthy participants, andin the left frontal region the depression more power for gamma. In addition, the gammadisplayed relatively less power for positive and neutral picture over the frontal region ascompared to negative picture in depressed participants.Compared to healthy participants, in contrast to general intrahemispheric, theresults of the gamma activity in depressed participants is right hemisphere dominancefor positive and lateralization towards the left hemisphere for processing of negativeemotional material. And depressed individuals exhibit cognitive biases in negativeinformation processing.