Premium
Viewing the body prepares the brain for touch: effects of TMS over somatosensory cortex
Author(s) -
Fiorio Mirta,
Haggard Patrick
Publication year - 2005
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/j.1460-9568.2005.04267.x
Subject(s) - somatosensory system , stimulus (psychology) , secondary somatosensory cortex , psychology , neuroscience , tactile perception , somatosensory evoked potential , transcranial magnetic stimulation , perception , sensory stimulation therapy , visual cortex , stimulation , audiology , cognitive psychology , medicine
Viewing the body can improve tactile perception. We investigated whether this could be due to a remodeling of somatosensory cortical areas during vision of the body. Single‐pulse transcranial magnetic stimulation (TMS) was delivered over the primary and secondary somatosensory areas of subjects who showed clear visual‐tactile enhancement while they performed a tactile grating discrimination task. Before the tactile stimulus, subjects viewed either their right index finger through a semisilvered mirror or an object reflected by the mirror and positioned to appear in the same location as the finger. In a first experiment we observed that TMS over primary somatosensory cortex significantly reduced subjects' accuracy whilst viewing the hand. No such reduction was found when subjects viewed a neutral object. In a second experiment, we disrupted the activity of primary and secondary somatosensory areas in different sessions. When stimulating the primary somatosensory cortex, a reduction in accuracy was again found while viewing the hand, but not a neutral object. TMS over secondary somatosensory cortex had no effect in any condition. Our results show that vision of the body may act at an early stage in stimulus elaboration and perception, allowing an anticipatory tuning of the neural circuits in primary somatosensory cortex that underlie tactile acuity.