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

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.

[1]  M. Hallett,et al.  Functional relevance of cross-modal plasticity in blind humans , 1997, Nature.

[2]  A. Paans,et al.  Brain Activation Related to the Representations of External Space and Body Scheme in Visuomotor Control , 2001, NeuroImage.

[3]  F. Lacquaniti,et al.  Combination of hand and gaze signals during reaching: activity in parietal area 7 m of the monkey. , 1997, Journal of neurophysiology.

[4]  M. Hallett,et al.  Activation of the primary visual cortex by Braille reading in blind subjects , 1996, Nature.

[5]  Scott T. Grafton,et al.  Involvement of visual cortex in tactile discrimination of orientation , 1999, Nature.

[6]  Kando Kobayashi,et al.  The precuneus in motor imagery: a magnetoencephalographic study , 2000, Neuroreport.

[7]  C. Michel,et al.  High metabolic activity in the visual cortex of early blind human subjects , 1988, Brain Research.

[8]  K. Zilles,et al.  Line bisection judgments implicate right parietal cortex and cerebellum as assessed by fMRI , 2000, Neurology.

[9]  A M Dale,et al.  Optimal experimental design for event‐related fMRI , 1999, Human brain mapping.

[10]  H Summala,et al.  Auditory processing in visual brain areas of the early blind: evidence from event-related potentials. , 1993, Electroencephalography and clinical neurophysiology.

[11]  Richard A. Andersen,et al.  Separate body- and world-referenced representations of visual space in parietal cortex , 1998, Nature.

[12]  C. Frith,et al.  Modulation of human visual cortex by crossmodal spatial attention. , 2000, Science.

[13]  G. Rizzolatti,et al.  Localization of grasp representations in humans by PET: 1. Observation versus execution , 1996, Experimental Brain Research.

[14]  M. Denis,et al.  Functional Anatomy of Spatial Mental Imagery Generated from Verbal Instructions , 1996, The Journal of Neuroscience.

[15]  R. C. Oldfield.  The assessment and analysis of handedness: the Edinburgh inventory. , 1971, Neuropsychologia.

[16]  A M Dale,et al.  Randomized event‐related experimental designs allow for extremely rapid presentation rates using functional MRI , 1998, Neuroreport.