Learning during anaesthesia: a review.

Can learning occur during general anaesthesia? This paper reviews the studies which have addressed this issue and finds some evidence of implicit memory for intra-operative events, even with clinically adequate anaesthesia. This has implications both for clinical practice and for psychological theories of learning and awareness. However, since many of the studies have been opportunistic, neither the anaesthetic techniques nor the paradigms used to assess memory have been standardized. Methodological improvements are discussed, in particular the need for a reliable means of monitoring awareness during anaesthesia. These improvements would enable researchers to determine the conditions under which learning occurs and would provide information about the role of consciousness in learning.