EEG Source localization analysis for local-global visual processing using sLORETA

The aim of this study was to assess whether Standardized Low Resolution Brain Electromagnetic Tomography (sLORETA) can detect differences in EEG source distribution during local and global stimuli cognition process or not. We recorded the cortical brain activity from 40 subjects (M:F=20:20) during local and global stimuli cognition process. The stimuli were generated based on the modified version of Navon´s hierarchical structured stimuli (Navon, 1977). We found the differences in 4~8 Hz theta oscillation during the task between male and female groups in sLORETA patterns, particularly in the right temporal cortex. We also found the similar theta oscillation patterns in power spectrum analysis: higher synchronized theta activity between posterior parietal lobe and frontal lobe was found in female group than that of male group. These findings suggest higher dependence on local-global stimulation cognition and memory recall in female. We suggest that sLORETA can be a good tool for detecting local-global stimulus cognition and be a good diagnostic for the neuropsychiatric disorders related to the local-global processing such as Obsessive-compulsive disorder and Posttraumatic stress disorder