Selective visual interference with right hemisphere performance in verbal recall. A divided field study.

Three experiments were performed in normal subjects to find out whether interhemispheric functional asymmetries in oral recall of meaningless trigrams of consonants, laterally presented through a tachistoscope, were affected by the subsequent presentation and the immediate recall of visual (verbal and geometrical) vs auditory information. It was shown that the visual presentation of after-target information brought about a right hemisphere disadvantage, which did not occur when the additional information was presented auditorily. The results are consistent with the view that, as to visually presented letters, the right hemisphere processing systems run along a physical code.