Mental Changes Resulting from the Passage of Small Direct Currents Through the Human Brain

Abstract

A trial is described in which differentiation was made at the 0.001 level of significance between the mental changes produced by passing small direct currents through the brain in opposite directions. The greatest effects are produced when current is passed between electrodes above the eyebrows and an electrode on the right leg. When the scalp electrodes are positive and the total current flow is up to 500 µA, the mental changes commonly consist of an elevation of mood and an increased involvement in the environment; scalp-negative current flow produces withdrawal and quietness.