The coherence changes in the depressed patients in response to different facial expressions

Abstract

To characterize the changes of information transfer between different brain regions during facial expressions processing between the depressed patients and the normal subjects, we applied partial-directed coherence analysis (PDC). Participants were 16 depressed patients and 26 normal subjects, age-matched between groups. An emotion recognition task with different facial expressions (positive and negative) was utilized as stimuli. Lower frontal output PDC values in the alpha band reflected the poor frontal cortex's regulation of parieto-occipital regions in depressed patients, while the enhanced outflow from the posterior regions to the frontal regions could be taken as an indicator that the depressed group attempted to achieve the normal performance. These topographic patterns of electrical coupling might indicate the changing functional cooperation between the brain areas in depressed patients. The depressed patients may have abnormal brain areas comprising bilateral frontal, right temporal, parietal and occipital regions. © 2010 Springer-Verlag.