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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Transcranial direct current stimulation can selectively affect different processing channels in human visual cortex

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Autor(es):
Costa, Thiago L. [1, 2, 3, 4] ; Hamer, Russell D. [5, 3, 6] ; Nagy, Balazs V. [3] ; Barboni, Mirella T. S. [3] ; Gualtieri, Mirella [3] ; Boggio, Paulo S. [1, 2] ; Ventura, Dora F. [3]
Número total de Autores: 7
Afiliação do(s) autor(es):
[1] Univ Prebiteriana Mackenzie, Ctr Hlth & Biol Sci, Social & Cognit Neurosci Lab, Sao Paulo - Brazil
[2] Univ Prebiteriana Mackenzie, Ctr Hlth & Biol Sci, Dev Disorders Program, Sao Paulo - Brazil
[3] Univ Sao Paulo, Dept Psicol Expt, Inst Psicol, Sao Paulo - Brazil
[4] Cidade Univ Sao Paulo, Inst Psicol, BR-05508030 Sao Paulo - Brazil
[5] Smith Kettlewell Eye Res Inst, San Francisco, CA 94115 - USA
[6] Florida Atlantic Univ, Dept Psychol, Boca Raton, FL 33431 - USA
Número total de Afiliações: 6
Tipo de documento: Artigo Científico
Fonte: Experimental Brain Research; v. 233, n. 4, p. 1213-1223, APR 2015.
Citações Web of Science: 3
Resumo

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that can modulate cortical activity. Nonetheless, information regarding its functional specificity and the extent by which visual performance can be modulated is still lacking. Here, we used vision as model to address if it differentially affects different cell groups in the stimulated area. We applied tDCS to the occiput and performed a series of visual tests in a sham-controlled repeated-measures design. Achromatic contrast sensitivity was assessed psychophysically during tDCS, with tasks designed to target specific spatial frequency (SF) channels, inferred ON, OFF channels and inferred magnocellular and parvocellular pathways of the visual system. Sweep visual evoked potential (sVEP) for contrast sensitivity and Vernier acuity was recorded before and after tDCS. Anodal tDCS significantly increased thresholds for luminance decrements (OFF) only for the inferred magnocellular thresholds. Although tDCS had no significant effects on Vernier or contrast sVEP thresholds, it modulated suprathreshold amplitudes for both tasks. Cathodal tDCS increased sVEP amplitudes at a low SF, decreased it at a medium, and had no effect at a high SF. Cathodal tDCS increased sVEP phase lags for low and decreased it for high SF (maximum change corresponding to change in apparent latency > 6 ms). Cathodal and anodal stimulation decreased amplitudes of sVEP Vernier responses. Exclusive tDCS effects on magnocellular thresholds agree with reports of pathway-specific tDCS effects. The dependence of tDCS effects on SF and contrast levels further suggests that tDCS differentially affects different cell groups in the visual cortex. (AU)

Processo FAPESP: 09/54292-7 - Avaliacao do desempenho visual em diferentes condicoes de iluminacao artificial com caracteristicas espectrais variadas
Beneficiário:Balazs Vince Nagy
Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
Processo FAPESP: 08/58731-2 - A visão como indicador de processos lesivos na retina e no sistema nervoso central
Beneficiário:Dora Selma Fix Ventura
Modalidade de apoio: Auxílio à Pesquisa - Temático
Processo FAPESP: 11/10794-9 - Modulação do Sistema Visual Humano Através de Estimulação Transcraniana por Corrente Contínua
Beneficiário:Thiago Leiros Costa
Modalidade de apoio: Bolsas no Brasil - Doutorado
Processo FAPESP: 07/55125-1 - Avaliação eletrofisiológica e psicofísica das vias visuais on e off em jovens com Distrofia Muscular de Duchenne
Beneficiário:Mirella Telles Salgueiro Barboni
Modalidade de apoio: Bolsas no Brasil - Doutorado