Titre du document / Document title

Involvement of visual cortex in tactile discrimination of orientation

Auteur(s) / Author(s)

ZANGALADZE A. ⁽¹⁾ ; EPSTEIN C. M. ⁽¹⁾ ; GRAFTON S. T. ⁽¹⁾ ; SATHLAN K. ⁽¹⁾ ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

⁽¹⁾ Department of Neurology, Emory University School of Medicine, WMRB-6000, PO Drawer V, 1639 Pierce Drive, Atlanta, Georgia 30322, ETATS-UNIS

Résumé / Abstract

The primary sense modalities (vision, touch and so on) are generally thought of as distinct. However, visual imagery is implicated in the normal tactile perception of some object properties, such as orientation', shape and size², Furthermore, certain tactile tasks, such as discrimination of grating orientation¹ and object recognition³, are associated with activity in areas of visual cortex. Here we show that disrupting function of the occipital cortex using focal transcranial magnetic stimulation (TMS) interferes with the tactile discrimination of grating orientation. The specificity of this effect is illustrated by its time course and spatial restriction over the scalp, and by the failure of occipital TMS to affect either detection of an electrical stimulus applied to the fingerpad or tactile discrimination of grating texture. In contrast, TMS over the somatosensory cortex blocked discrimination of grating texture as well as orientation. We also report that, during tactile discrimination of grating orientation, an evoked potential is recorded over posterior scalp regions with a latency corresponding to the peak of the TMS interference effect (about 180 ms). The findings indicate that visual cortex is dosely involved in tactile discrimination of orientation. To our knowledge, this is the first demonstration that visual cortical processing is necessary for normal tactile perception.

Revue / Journal Title

Nature   ISSN 0028-0836   CODEN NATUAS 

Source / Source

1999, vol. 401, n^o6753, pp. 587-590 (24 ref.)

Langue / Language

Anglais

Editeur / Publisher

Nature Publishing, London, ROYAUME-UNI  (1869) (Revue)

Mots-clés anglais / English Keywords

Tactile sensitivity ; Mechanical stimulus ; Spatial orientation ; Discrimination task ; Visual cortex ; Emission tomography ; Evoked potential ; Human ; Visual pathway ; Brain (vertebrata) ; Central nervous system ;

Mots-clés français / French Keywords

Sensibilité tactile ; Stimulus mécanique ; Orientation spatiale ; Tâche discrimination ; Cortex visuel ; Tomoscintigraphie ; Potentiel évoqué ; Homme ; Voie visuelle ; Encéphale ; Système nerveux central ;

Mots-clés espagnols / Spanish Keywords

Sensibilidad tactil ; Estímulo mecánico ; Orientación espacial ; Tarea discriminatoria ; Corteza visual ; Tomocentelleografía ; Potencial evocado ; Hombre ; Vía visual ; Encéfalo ; Sistema nervioso central ;

Localisation / Location

INIST-CNRS, Cote INIST : 142, 35400008805385.0220