The Study Of Visual Information Processing Mechanism Based On Electroencephalography

More than 80% of our sensory information comes from our eyes.Visual information processing system shows astonishing efficiency,accuracy and stability even when drown into complex information of the world,therefore draws the interest of many researchers.In order to explore this meaningful subject,we conducted a two-part research,both of which dedicated to one special visual input and helped us understand the mechanism of visual information processing better.Our research started with the process of facial information in brain.In this part,we analyzed “face effect” and “inversion effect”,both of which are fundamental in facial information processing.By comparing P1 and N170 differences among four stimulations(“upright face”,“upright non-face”,“ inverted face” and “ inverted non-face”),we found and made a possible explanation for the absence of “inverted face effect” of N170 latency.Surrounding the early “face effect” of P1 amplitude,we also discussed the question when did facial information processing start.Given the close relationship between social anxiety disorder(SAD)and facial information processing,we tried to make a comparison of event related potential(ERP)between SAD group and normal control group,and found some differences which were listed below:(1)N170 amplitude of SAD group is higher than the control group’s(2)P1 of SAD group peaks slower than control group(3)Amplitude of upright “face/non-face” N170 difference wave shows more significant right hemisphere advantage in SAD group than control group(4)Amplitude of inverted “face/non-face” N170 difference wave is higher in SAD group than in the control groupThe second part of our research focused on cerebral response to auditory signal coded by visual pattern.Visual-auditory sensory substitution phenomenon found in visually impaired people inspires us a lot.We designed a paradigm to instruct subject to extract visual information contained in sound.Through analyzing the frequency spectral analysis of electroencephalography(EEG)collected in this procedure,power spectrum rise ranging(at least)from 16 to 40 Hz was observed in occipital and bilateral occipito-temperal areas,which could be an evidence of “pathway independence” of visual information processing system.