Weak direct currents (DC) applied to the brain have been shown to influence neuronal activity. In this study 0.3 mA DC were applied externally through electrodes placed on the scalp. Electrode positions were above the right and left central sulcus close to the hand representation in primary motor and somatosensory cerebral cortex. Current flow resulted in lateralized polarization of centro-parietal cortex. The first experiment deals with the effects of current-polarity on a tactile discrimination task presented to either of both hands. Side-specific effects on reaction time and EEG are shown. Responses are facilitated if the current source is contralateral, and the current sink is ipsilateral, to the responding hand. DC effects on lateralization were confirmed in a second study in which subjects had to press a button with either hand in response to presentation of a 100 ms tone. It is concluded that brain processes can be selectively altered by application of event-related currents.
|Number of pages||7|
|Journal||Journal of Psychophysiology|
|Publication status||Published - 1987|
ASJC Scopus subject areas
- Neuropsychology and Physiological Psychology