IMPLICIT MEMORY FOR STIMULI PRESENTED DURING ANESTHESIA - ROLE OF ANESTHETIC COCKTAIL AND MEMORY TEST

Recently, investigators have used so-called implicit memory tests to i nvestigate 'hearing' during general anaesthesia. Some of them were abl e to demonstrate auditory perception in anaesthetized patients, but ot hers have failed to find any evidence for intraoperative stimulus regi stration. We argue that differences in anaesthetic cocktails and memor y tests can explain why some researchers have produced positive result s, supportive of information-processing under anaesthesia, and others have not. It appears that stimulus registration can occur during surge ry, regardless of anaesthetic technique. However, processing of comple x information may only be possible during nitrous oxide anaesthesia.