Right to left hemispheric shift in occipital electroencephalographic responses to repeated Kimura figures.

Gordon and Carmon (1976) reported that repeated presentations of an initially novel stimulus were associated with a transfer of cerebral dominance over time (trials) from the right to the left hemisphere. To test the generalizability of these results the proportions of alpha rhythms over the left and right occipital and parietal lobes were measured following the presentation of recurring and nonrecurring complex visual patterns (the Kimura Figures) to the upper or lower, left or right peripheral visual fields. Analysis showed increased electrical activation (as inferred by attenuated proportions of alpha rhythms) of the left occipital lobe but decreased activation of the right occipital lobe. This shift occurred during repeated presentations of the same stimuli but not during single presentations of different novel stimuli. There was no significant shift in this activity over the parietal 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.