Dorsal visual cortex activity elicited by posture change in a visuo-tactile matching task

Abstract

To investigate the process of crossmodal spatial recognition, we examined the effect of posture change on the recognition of a tactile stimulus position. The task was to judge whether a visual and a tactile stimulus, presented to the left or right, were on the same or different sides while subjects crossed or uncrossed their hands. Under a condition which removed the effect of response bias to the left and right, the dorsal visual cortex (area 18/19) and the precuneus were more activated in the crossed hands condition. The dorsal visual cortex activation suggests that the acti-vity of brain areas classically considered to be visual cortex is affected by posture change, and reflects the reciprocal process across different modalities in spatial recognition.