Direct electrical stimulation of specific human brain structures and bilateral electrodermal activity.

We are presenting data of research conducted for the first time with human subjects in whom specific intracerebral sites were electrically stimulated through intracerebral electrodes with the concomitant recording of bilateral electrodermal activity. Direct electrical stimulation of specific intracerebral structures for which electrodermal responses were analyzed were the amygdalae, the anterior and posterior hippocampi, the anterior cingulate gyri, the frontal cortical convexities and the mid-region of the second temporal gyri, bilaterally. ANOVA data (side stimulated x stimulation intensity x hand) have shown that significant main effects were found for side stimulated and stimulation intensity for limbic structures only. These results provide strong evidence that human bilateral electrodermal activity is under strong ipsilateral control when limbic structures are stimulated. Moreover, with the stimulation of cortical sites, either absence of response or weak ipsilateral, contralateral, or bilaterally equal influences seem to be operative in the elicitation of bilateral electrodermal activity.