| Abstract: | The averaged visual cortical evoked potential (VEP) was examined in two separate experiments us a function of stimulus location. The VEP was recorded from over left and right occipital hemispheres and stimuli were presented binocularly. The results of Experiment I, in which three stimulus locations were used, indicated that stimuli presented in the left visual field resulted in shorter VKP latencies at the right occipital area than the left, while for stimuli presented in the right visual field, the opposite occurred. In Experiment II, seven locations were used and similar VEP latency asymmetries were observed. White no hemispheric amplitude asymmetries were found, there was a trend toward a decrease of VEP amplitude with increasing distance of stimulation from the fovea. The latency asymmetries may he explained in terms of the angle at which the stimuli impinge upon the retinas of the two eyes from different locations. Direct stimulation is produced at the primary projection area, whereas indirect stimulation probably occurs at the secondary area, after crossover of impulses via the corpus callosum. |
