Affiliations: Department of Clinical Neurophysiology, University Medical Center, Georg-August University of Göttingen, Göttingen, Germany | Institute of Psychology, University of Regensburg, Regensburg, Germany | Department of Cognitive Science, Budapest University of Technology and Economics, Budapest, Hungary
Note: [] These authors contributed equally. Corresponding author: Andrea Antal, PhD, Department of Clinical Neurophysiology, Georg-August University of Göttingen, 37075 Göttingen, Robert Koch Straße 40, Germany, Tel.: +49 551 398461; Fax: +49 551 398126; E-mail: [email protected]
Note: [] These authors contributed equally.
Abstract: Purpose: Transcranial direct current stimulation (tDCS) was reintroduced about a decade ago as a tool for inducing long-lasting changes in cortical excitability. Recently it has been shown that both motor and cognitive functions can be influenced by tDCS. Here, we tested the effect of tDCS on the blood-oxygen level dependent (BOLD) signal evoked by coherent visual motion using functional magnetic resonance imaging (fMRI). Methods: The subjects underwent 10 min of cathodal and sham tDCS, applied over the right MT+. Following stimulation, random dot kinomatograms (RDK) with different percentages (10%, 30%, 50%) of coherently moving dots were presented. Results: All motion stimuli activated MT+ in both stimulation conditions. However, cathodal stimulation led to an increase in fMRI signal in MT+ when compared to sham stimulation. This effect did not depend on the coherence level of the visual stimulus. Conclusions: Here, we show for the first time, that cathodal tDCS stimulation leads to elevated fMRI signal in the human visual cortex.
Keywords: Area MT+, fMRI, motion perception, transcranial direct current stimulation (tDCS)
