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Published on: January 13, 2018
Investigation of implicit memory during isoflurane anesthesia for elective surgery using the process dissociation
Irène A Iselin-Chaves1, Sylvie J Willems, Françoise C Jermann
1Department of Anesthesiology, University Hospital of Geneva, Switzerland. irene.iselin-chaves@hcuge.ch
Anesthesiology
|October 27, 2005
Summary
Implicit memory persists during general anesthesia, even at adequate hypnotic states. Explicit memory was not reliably detected, suggesting anesthesia impacts conscious recall more than subconscious processing.
Area of Science:
- Anesthesiology
- Cognitive Neuroscience
- Neuroscience
Background:
- Investigates memory function during general anesthesia for elective surgery.
- Examines the relationship between hypnotic state depth and memory.
- Compares memory function in anesthetized versus non-anesthetized individuals.
Purpose of the Study:
- To evaluate memory function under general anesthesia.
- To determine the influence of hypnotic state depth on memory.
- To compare memory performance between anesthetized and control groups.
Main Methods:
- Prospective study involving 48 patients undergoing elective surgery.
- Auditory word presentation during anesthesia, followed by memory assessment using auditory word stem completion.
- Bispectral Index (BIS) monitored to assess hypnotic state depth.
- Process dissociation procedure used to differentiate explicit and implicit memory.
Main Results:
- Memory evidence found during light (BIS 61-80) and adequate (BIS 41-60) anesthesia, but not deep anesthesia (BIS 21-40).
- Implicit memory contribution was significant, while explicit memory contribution was not reliable across hypnotic states.
- Non-anesthetized subjects demonstrated better memory performance, with higher explicit memory contribution.
Conclusions:
- Implicit memory persists during general anesthesia, even in adequate hypnotic states.
- Anesthesia's impact on memory is primarily on explicit recall rather than implicit processing.
- Findings suggest subconscious memory processing remains relatively intact during anesthesia.
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