anodal transcranial direct current stimulation reduces psychophysically measured surround suppression in the human visual cortex阳极的经颅直流电刺激减少了心理物理测量环绕在人类视觉皮层抑制.pdfVIP

Anodal Transcranial Direct Current Stimulation Reduces Psychophysically Measured Surround Suppression in the Human Visual Cortex 1 2 3 1 Daniel P. Spiegel , Bruce C. Hansen , Winston D. Byblow , Benjamin Thompson * 1 Department of Optometry and Vision Science, University of Auckland, Auckland, New Zealand, 2 Department of Psychology Neuroscience Program, Colgate University, Hamilton, New York, United States of America, 3 Department of Sport and Exercise Science, University of Auckland, Auckland, New Zealand Abstract Transcranial direct current stimulation (tDCS) is a safe, non-invasive technique for transiently modulating the balance of excitation and inhibition within the human brain. It has been reported that anodal tDCS can reduce both GABA mediated inhibition and GABA concentration within the human motor cortex. As GABA mediated inhibition is thought to be a key modulator of plasticity within the adult brain, these findings have broad implications for the future use of tDCS. It is important, therefore, to establish whether tDCS can exert similar effects within non-motor brain areas. The aim of this study was to assess whether anodal tDCS could reduce inhibitory interactions within the human visual cortex. Psychophysical measures of surround suppression were used as an index of inhibition within V1. Overlay suppression, which is thought to originate within the lateral geniculate nucleus (LGN), was also measured as a control. Anodal stimulation of the occipital poles significantly reduced psychophysical surround suppression, but had no effect on overlay suppression. This effect was specific to anodal stimulation as cathodal stimulation had no effect on either measure. These psychophysical results provide