Well-kept secrets of the right hemisphere: a carotid amytal study of restriced memory transfer

Verbal and nonverbal recall of a simple tactual stimulus was assessed in patients receiving left intracarotid injections of sodium amytal. During the period of dominant hemisphere anesthetization, a common object was presented to the left hand-right hemisphere but was kept out of view. Following recovery from the drug, six of the eight patients were unable to recall the object verbally, but recognized it immediately in a visual multiple-choice array. These results demonstrate a dissociation of verbal and nonverbal memory mechanisms which suggests that delayed interhemispheric transfer of a functional sensory message is highly improbable.