SV2. tDCS applied over the visual cortex modifies perception

Abstract

Transcranial direct current stimulation (tDCS) seems to be promising methods to induce visual cortical excitability and activity modulations. Furthermore, there are exciting prospects for the use of tDCS as a tool to promote changes of visual cortex activity paralleled by perceptual and behavioral improvements. However, compared to the motor cortex stimulation, the induced after-effects in the visual cortex are generally short-lived. Moreover, although anodal stimulation is known to increase and cathodal stimulation decreases cortical excitability, over the visual cortex they do not automatically result in better or worse perception or performance, as it was observed by stimulating the motor areas. Recently, significant efforts have been made to combine tDCS with other techniques, such as fMRI and EEG. The combination of these techniques are very important approach in learning more about localization, time course and functional specifications of a brain area involved in visual tasks. However, to make tDCS relevant not only for basic research purposes but also for clinical use, additional studies are necessary. There have been only a few studies in which the excitability of the occipital cortex was modified in order to gain clinical reimbursement, although, in some cases (e.g. photosensitive epilepsy, stroke or migraine), the application of tDCS could be therapeutically beneficial. This talk focuses on tDCS and summarizes the latest results with regard to the application of this method over the visual areas in healthy subjects and clinical populations.