Concurrent transcranial direct current stimulation (tDCS) and functional MRI reveals modulatory effects on brain activation during a simple motor task

Introduction: Anodal and cathodal transcranial direct current stimulations (tDCS) have been shown to have facilitatory and inhibitory effects, respectively, on the stimulated cortical networks. Given sufficient stimulation duration the effect of stimulation can outlast the duration of the stimulation for several hours [1]. Combining functional MRI (fMRI) with concurrent tDCS allows for a non-invasive detailed examination of tDCS-induced effects throughout the brain. In the present study we used concurrent tDCS-fMRI to test whether anodal and cathodal tDCS result in blood oxygenation level dependent (BOLD) fMRI signal changes in a resting condition. Furthermore, we examined the effects of tDCS on the brain network activated by a voluntary finger tapping task.