Preliminary Study On The Brain Cognitive Event Related Potential With Visual Fields

Purpose: To study different stimulation field’s ERP components, further toinvestigate the character and difference of visual information processing with differentvisual fields defect, and hope to provide basic information to explore the objectiveevaluation method of perspective.Method: The study orderly examined the electroencephalic response in a visualthree-stimulus oddball task, while20subjects with normal visual function were receivingdifferent stimulative fields with the other eye covered. According to the difference ofstimulative fields, the study were divided into five groups:5°、10°、20°、30°、60°visualfield or defect, and the ERP was recorded in each group.Results:(1) The P1mainly located at the occipito-temporal region. Along with theincrements of visual field, the latency of P1was prolonged and the P1amplitude wasincreased in a non-linear fashion, but the variation of latency and amplitude was oppositewhen the visual field was more than20°. The P1latency had not changed obviously andthe amplitude was decreased in a non-linear fashion with increase of defect, but theamplitude had not changed obviously when the visual field was more than30°.(2) The N1was over the extensive encephalic region, and the latency was graduallyprolonged from front to back. The N1amplitude in5°、10°、20°visual field and30°、60°visual field、defect stimulitavition was highest and lowest at the occipital region，respectively. When the size of stimulative field or defect was increasing, the N1latencywas prolonged and amplitude was increased. The N1was prolonged and higher in60°defect than10°visual field.(3) The P2mainly located at the prefrontal region. The P2was shorter and higher in5°、10°、20°visual field than30°、60°visual field. With the increasing of defect, the P2latency was prolonged, and amplitude had not changed obviously. (4) The N2was over the extensive encephalic region. The N2amplitude in5°、10°、20°visual field or defect and30°、60°visual field or defect was highest at the central and atthe parietal region, respectively. There was a prolonged and increasing tendency of N2with the area increasing of stimulative field or defect.(5) The P3mainly located at the parietal-occipital region. The P3was shorter andhigher in5°、10°、20°than30°、60°visual field or defect.Conclusions:(1) The scalp distribution of N1、N2was different between visual fields.(2)There was a correlation between stimulitive field and ERP components: the farer thetarget was to the center, the longer the latency was, the higher the amplitude of N1、N2was，and the lower the amplitude of P1、P2、P3was.