Right to left hemispheric shift in occipital electroencephalographic responses to repeated Kimura Figures

Gordon and Carmon (1976) reported that repeated presentations of an initial ly novel stimulus were associated with a transfer of cerebral dominance ove r time (trials) from the right to the left hemisphere. To rest the generali zability of these results the proportions of alpha rhythms over the left an d right occipital and parietal lobes were measured following the presentati on of recurring and nonrecurring complex visual patterns (the Kimura Figure s) to the upper or lower, left or right peripheral visual fields. Analysis showed increased electrical activation (as inferred by attenuated proportio ns of alpha rhythms) of the left occipital lobe bur decreased activation of the right occipital lobe. This shift occurred during repeated presentation s of the same stimuli but not during single presentations of different nove l stimuli. There was no significant shift in this activity over the parieta l lobes. These results are consistent with the reports of other researchers who have found a shift of dominant neuroelectrical activity from the right to the left hemisphere as the novelty of a visuospatial stimulus decreases .