Abstract

The present study examined the effects of stimulus type on Wada memory results. The subjects were 43 patients with medically intractable temporal lobe epilepsy (TLE) who had a good seizure outcome following epilepsy surgery. Of these, 26 had the epileptogenic foci in the left temporal lobe and 17 in the right temporal lobe. The Wada memory stimuli were concrete figures for 23 subjects and abstract figures for the other 20 subjects.. The stimuli were presented during effects of amobarbital and follow-up memory testing was performed using a yes-no recognition method. The left TLE group demonstrated better recall following left than right hemisphere injection, whereas the right TLE group scored higher following right than left hemisphere injection. The left hemisphere was superior to the right hemisphere for recognition memory of concrete figures, whereas the right hemisphere was superior to the left hemisphere for recognition memory of abstract figures. These findings indicate that stimulus type as well as seizure lateralization is a major determinant of Wada memory asymmetries.