Evidence for the involvement of the ventromedial prefrontal cortex in a short-term storage of visual images

The purpose of this study was to clarify the role of the ventromedial prefr ontal cortex in short-term visual memory. Patients with focal lesions to th e right gyrus rectus were impaired on a size judgement task, which required short-term retention of laterally presented visual patterns. The impairmen t was most evident when the stimuli were addressed to the damaged hemispher e (left visual field presentations) and when separated by very short (50-50 0 ms) intervals. The findings suggest that the ventro-medial part of the or bitofrontal cortex, like the ventro-lateral part, is involved in short-term storage of icon-like representations of visual objects, and also that ther e exists a right-hemispheric specialization for that function. Our study pr esents the first direct evidence of such specific memory effects in humans using a lesion method and points to the importance of the right gyrus rectu s area in maintaining the representation of stimuli after they are removed from view. NeuroReport 12:1187-1190 (C) 2001 Lippincott Williams & Wilkins.