The Intracarotid Amobarbital Sodium Procedure: False-Positive Errors During Recognition Memory Assessment

Memory performance during the intracarotid amobarbital sodium (Amytal sodium) procedure was examined in 40 patients as part of their diagnostic workup as candidates for epilepsy surgery. Free recall was significantly better following right hemisphere injection although no left/right difference was present during recognition assessment. However, the occurrence of false-positive (FP) recognition errors was significantly more frequent following left hemisphere injection. In all conditions, no relationship to seizure focus was observed. Patients with FP errors displayed poorer delayed verbal memory during baseline neuropsychological assessment compared with patients without FP errors. Data indicate an inverse relationship between FP errors and recent verbal memory function, and they suggest that impaired memory rather than failure to suppress incorrect responses secondary to poor self-monitoring capacity is responsible for the generation of FP and intrusion errors.