Nancy Melucci wrote:
> Yesterday morning I heard a psychologist interviewed on the public radio show
> "The Infinite Mind" who claimed that she'd woken up during surgery and could
> feel what was being done to her although she was totally paralyzed from the
> drugs and could not tell anyone she was awake....
>
> Is there any data on this particular experience either supporting the
> frequency this psychologist claimed for it (150,000 incidents per year) or is
> this too new, or has it been otherwise verified by anesthesiologists
> themselves who are seeking to eliminate this danger? (Skeptic that I am, I
> still know that stuff happens.)
Sandra Nagel Randall mentioned the effects of ketamine on memory. Stephen Black
mentioned some work by Levinson:
> Aside from the ketamine issue, there are some old papers which purport
> to demonstrate that patients under anesthesia may still be aware. One
> of these is a study by Levinson (1967) using a methodology which the
> ethics committee would never let him get away with today.
>
> Patients underwent surgery using EEG monitoring to ensure deep
> anesthesia. However, before the actual surgery began but while the
> patient was deeply anesthetized, the anesthetist would stop the
> operation and declare (falsely) that the patient's lips were too blue
> and the anesthestist would administer more oxygen.
>
> So far, so good (except for ethics). But the post-poperative
> assessment is problematic. It was carried out a month later using
> hypnosis. Levinson reported that 4 of 10 subjects were able to repeat
> "practically verbatim" the anesthetist's words, and a further four
> patients exhibited anxiety during the session. His recommendation was
> that doctors keep their mouths shut during surgery.
>
>
Stephen concluded that the claim that people can be aware (and able to remember)
while under general anesthesia was questionable. In the British Journal of
Psychology, Andrade (1995) reviewed research on this claim. I don't have the
reference handy, but Logie & Della Salla (1999) summarized its major conclusion:
"it has become clear that although patients are in a state of clinically induced
anaesthesia it is possible for them to be aware, at the time, of events during
the operation, but to forget after the operation that they have had this
experience. It appears that there are several forms of anaesthetic state that
can be induced, depending on the form of anaesthetic used and the dosage for an
individual. A patient can be unable to move, but nevertheless be conscious and
feel pain. They can also be unable to move, free of pain but able to hear and
understand events that occur. Moreover, they may forget the experience but
nevertheless show by indirect tests that they had learned something about events
during the operation" (p. 132)
Logie & Della Salla present one example:
"Schwender et al. (1993) studied three groups of patients. Each group was given
different forms of anaesthetic and the brain activity (EEG) was measured via
electrodes attached to the head of each patient. The EEG pattern showed that the
three groups differed in their anaesthetic state corrsponding to different
levels of consciousness. While under anaesthetic, two of the groups of patients
were played a tape of part of the story of Robinson Crusoe. Between 3 and 5 days
after the operations, each patient was asked to free-associate to the word
'Friday'.... Among the group of 10 patients whose EEG pattern were closest to
that found in the normal waking state, five responded with 'Robinson Crusoe'.
However, in the other group, whose EEG activity was suppressed by the
anaesthetic, only 1 of the 10 patients responded with the word 'Robinson
Crusoe'...." (p. 132)
Thus, implicit memories may be formed during general anesthesia. This suggests
to me that, in some cases, a person might also later explicitly remember events
occuring during surgery. I will request Andrade's review through interlibrary
loan to see if a better answer is given there.
Jeff
REFERENCES
Andrade, J. (1995). Learning during anaesthesia: A review. _British Journal of
Psychology_, _86_, 479-506.
Logie, R. H. & Della Salla, S. (1999). Repetita (non) Iuvant. In S. Della Salla
(Ed.), _Mind myths: Exploring popular assumptions about the mind and brain_
(pp.125-137). New York: John Wiley & Sons.
Schwender, D., Kaiser, A., Klasing, S., Peter, K., & Poppel, E. (1993). Explicit
and implicit memory and mid-latency auditory evoked potential during cardiac
surgery. In P. S. Seber, B. Bonke, & E. Winograd (Eds.), _Memory and awareness
in anaesthesia_ (pp. 85-98). Englewood Cliffs, NJ: Prentice Hall.
--
Jeffry P. Ricker, Ph.D. Office Phone: (602) 423-6213
9000 E. Chaparral Rd. FAX Number: (602) 423-6298
Psychology Department [EMAIL PROTECTED]
Scottsdale Community College
Scottsdale, AZ 85250
"We humans are strange creatures."
Susan Blackmore
