TMS of the occipital cortex induces tactile sensations in the fingers of blind Braille readers

TY - JOUR

T1 - TMS of the occipital cortex induces tactile sensations in the fingers of blind Braille readers

AU - Ptito, M

AU - Fumal, A

AU - de Noordhout, A Martens

AU - Schoenen, J

AU - Gjedde, A

AU - Kupers, R

N1 - Keywords: Adult; Blindness; Brain Mapping; Female; Fingers; Functional Laterality; Humans; Language; Learning; Male; Neural Pathways; Neuronal Plasticity; Pattern Recognition, Visual; Reading; Sensory Aids; Sensory Deprivation; Somatosensory Cortex; Touch; Transcranial Magnetic Stimulation; Verbal Behavior; Visual Cortex

PY - 2008

Y1 - 2008

N2 - Various non-visual inputs produce cross-modal responses in the visual cortex of early blind subjects. In order to determine the qualitative experience associated with these occipital activations, we systematically stimulated the entire occipital cortex using single pulse transcranial magnetic stimulation (TMS) in early blind subjects and in blindfolded seeing controls. Whereas blindfolded seeing controls reported only phosphenes following occipital cortex stimulation, some of the blind subjects reported tactile sensations in the fingers that were somatotopically organized onto the visual cortex. The number of cortical sites inducing tactile sensations appeared to be related to the number of hours of Braille reading per day, Braille reading speed and dexterity. These data, taken in conjunction with previous anatomical, behavioural and functional imaging results, suggest the presence of a polysynaptic cortical pathway between the somatosensory cortex and the visual cortex in early blind subjects. These results also add new evidence that the activity of the occipital lobe in the blind takes its qualitative expression from the character of its new input source, therefore supporting the cortical deference hypothesis.

AB - Various non-visual inputs produce cross-modal responses in the visual cortex of early blind subjects. In order to determine the qualitative experience associated with these occipital activations, we systematically stimulated the entire occipital cortex using single pulse transcranial magnetic stimulation (TMS) in early blind subjects and in blindfolded seeing controls. Whereas blindfolded seeing controls reported only phosphenes following occipital cortex stimulation, some of the blind subjects reported tactile sensations in the fingers that were somatotopically organized onto the visual cortex. The number of cortical sites inducing tactile sensations appeared to be related to the number of hours of Braille reading per day, Braille reading speed and dexterity. These data, taken in conjunction with previous anatomical, behavioural and functional imaging results, suggest the presence of a polysynaptic cortical pathway between the somatosensory cortex and the visual cortex in early blind subjects. These results also add new evidence that the activity of the occipital lobe in the blind takes its qualitative expression from the character of its new input source, therefore supporting the cortical deference hypothesis.

U2 - 10.1007/s00221-007-1091-0

DO - 10.1007/s00221-007-1091-0

M3 - Journal article

C2 - 17717652

SN - 0014-4819

VL - 184

SP - 193

EP - 200

JO - Experimental Brain Research

JF - Experimental Brain Research

IS - 2

ER -