Rapid enhancement of touch from non-informative vision of the hand

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• 作者：Flavia Cardini ; Matthew R. Longo ; Jon Driver ; Patrick Haggard
• 关键词：Event related potentials ; Multisensory interaction ; Somatosensory processing ; Visual enhancement of touch
• 刊名：Neuropsychologia
• 出版年：2012
• 出版时间：July, 2012
• 年：2012
• 卷：50
• 期：8
• 页码：1954-1960
• 全文大小：503 K

文摘

Processing in one sensory modality may modulate processing in another. Here we investigate how simply viewing the hand can influence the sense of touch. Previous studies showed that non-informative vision of the hand enhances tactile acuity, relative to viewing an object at the same location. However, it remains unclear whether this Visual Enhancement of Touch (VET) involves a phasic enhancement of tactile processing circuits triggered by the visual event of seeing the hand, or more prolonged, tonic neuroplastic changes, such as recruitment of additional cortical areas for tactile processing. We recorded somatosensory evoked potentials (SEPs) evoked by electrical stimulation of the right middle finger, both before and shortly after viewing either the right hand, or a neutral object presented via a mirror. Crucially, and unlike prior studies, our visual exposures were unpredictable and brief, in addition to being non-informative about touch. Viewing the hand, as opposed to viewing an object, enhanced tactile spatial discrimination measured using grating orientation judgements, and also the P50 SEP component, which has been linked to early somatosensory cortical processing. This was a trial-specific, phasic effect, occurring within a few seconds of each visual onset, rather than an accumulating, tonic effect. Thus, somatosensory cortical modulation can be triggered even by a brief, non-informative glimpse of one's hand. Such rapid multisensory modulation reveals novel aspects of the specialised brain systems for functionally representing the body.