Research ArticlePSYCHOLOGY

Propofol-induced deep sedation reduces emotional episodic memory reconsolidation in humans

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Science Advances  20 Mar 2019:
Vol. 5, no. 3, eaav3801
DOI: 10.1126/sciadv.aav3801
  • Fig. 1 Study protocol.

    All patients, randomly assigned to one of two groups (A or B), underwent three sessions. Session 1 corresponded to day 1 and was the encoding session of the two emotional stories. Session 2 took place 7 days after day 1. All participants performed a memory reactivation task for one of the two emotional stories in the endoscopy unit. Immediately after, they received propofol, followed by the endoscopy procedure. For group B, session 3, the recognition memory test took place after the participants recovered from the procedure and were discharged from the recovery room. For group A, session 3 took place 24 hours after the endoscopy.

  • Fig. 2 Propofol impaired memory for the reactivated story when tested after 24 hours (group A) but not when tested immediately after recovery from anesthesia (group B).

    (A) Recognition memory scores for all slides of the reactivated and nonreactivated story (except the first slide) are plotted for each group. Scores (percentage) for each story per group: group A (n = 25 participants) reactivated mean (SEM) = 53.49 (2.29); nonreactivated mean = 59.20 (2.60); group B (n = 24 participants) reactivated mean = 59.52 (1.97); nonreactivated mean = 61.19 (2.11). (B) Percent correct recognition memory scores are plotted for the three story phases of the reactivated (R; solid line) and nonreactivated (NR; dashed line) story for each group. There is a significant impairment of memory for the emotional phase of the reactivated story (phase 2) in group A only. Chance recognition performance (25%) is indicated by the dotted horizontal line. *P < 0.05.

  • Table 1 Participant demographics and clinical details.

    Twenty-five patients per group completed the study. One patient in group B was not included in analyses because of outlier-level performance on the DSST before recognition testing. Groups A and B did not differ on any demographical variables (age, gender, years of education, or type of endoscopy procedure) or in terms of dosage of other agents (midazolam or alfentanil) administered. However, there was a significant difference in the amount of propofol administered.

    Group AGroup BStatistic (t, X2)P
    Age (years)Mean38.8839.08t47 = −0.150.88
    Years of schoolingMean14.4414.75t47 = −0.380.70
    Endoscopy procedure*Colonoscopy1310χ(2)2=2.970.23
    Endoscopy diagnosis*Not pathological1518χ(5)2=2.60.76
    Propofol (mg/kg)Mean3.022.37t47 = 2.040.047
    Duration of deep sedation (min)Mean13.1711.42t47 = 0.930.36
    Other pharmacological agents*Yes1313χ(1)2=0.0230.88
    Midazolam in mgn88
    Mean2.051.37t14 = 1.650.12
    Alfentanil in mgn77
    Mean0.290.30t12 = −0.080.94


    †Independent t test.

    ‡Significant at P < 0.05.

    Supplementary Materials

    • Supplementary Materials

      This PDF file includes:

      • Fig. S1. DSST performance for groups A and B.
      • Fig. S2. Memory reactivation scores.
      • Fig. S3. Reconsolidation impairment is not correlated with propofol dose.

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