Enhanced visual memory effect for negative versus positive emotional content is potentiated at sub-anaesthetic concentrations of thiopental Journal Article


Authors: Pryor, K. O.; Veselis, R. A.; Reinsel, R. A.; Feschenko, V. A.
Article Title: Enhanced visual memory effect for negative versus positive emotional content is potentiated at sub-anaesthetic concentrations of thiopental
Abstract: Background. Emotional information has the ability to alter the formation and strength of a memory ('memory modulation'). Memory modulation by negative emotion is mediated by the amygdala. It is not known how gamma aminobutyric acid (GABA)ergic drugs affect the processes involved in memory modulation. This study investigates whether memory for negative emotional stimuli is more refractory to the effects of GABAergic drugs. Methods. Eighty-three healthy volunteers were shown a randomized sequence of 60 visual stimuli consisting of negative, positive and neutral emotive pictures, while receiving a controlled infusion of thiopental (n=31), propofol (n=31), dexmedetomidine (n=10) or placebo (n=11). After a 5 h retention interval, when drug concentration was negligible, subjects performed a recognition task with 'old' pictures randomly mixed with 'new' pictures. Drug effect was calculated as the proportionate reduction in recognition for images of each emotional valence. Results. Forty-eight subjects were included in a within-subject logistic dose-response model analysis. In the thiopental group there was a smaller drug effect seen for negative vs positive images (proportional memory reduction from baseline 0.27 (SD 0.20) vs 0.56 (0.25), P<0.001, n=20 included in analysis). A similar trend was seen in the propofol group (0.25 (0.28) vs 0.54 (0.30), n=10), but this did not attain statistical significance. No trend was seen in the dexmedetomidine group (0.33 (0.26) vs 0.24 (0.22), n=7). Conclusions. Over a specific dose range of thiopental (target serum concentration 2-7 μg ml-1), impairment of explicit memory for images with negative emotional valence is less than that for images with positive emotional valence. There is a strong possibility that propofol (target serum concentration 0.3-2.4 μg ml-1) causes a similar effect. Modulation of visual memory by negative emotional content continues at sub-anaesthetic concentrations of GABAergic drugs associated with explicit memory impairment. © The Board of Management and Trustees of the British Journal of Anaesthesia 2004.
Keywords: adult; controlled study; middle aged; clinical trial; placebo; dose response; drug megadose; methodology; low drug dose; controlled clinical trial; randomized controlled trial; propofol; neuromodulation; drug effect; dose-response relationship, drug; drug receptor binding; blood; statistical significance; gabaergic transmission; drug infusion; emotion; drug blood level; lidocaine; memory disorder; pattern recognition, visual; photic stimulation; recognition; emotionality; emotions; amnesia; task performance; volunteer; concentration response; normal human; anesthetics, intravenous; human experiment; calculation; dexmedetomidine; thiopental; photostimulation; recall; mental recall; pattern recognition; visual memory; visual stimulation; intravenous anesthetic agent; humans; human; male; female; priority journal; article; anaesthetics, i.v.; brain, disease; brain, function; gaba receptors; gaba, brain; memory, brain; benzodiazepine receptor affecting agent; gaba modulators; recognition (psychology)
Journal Title: British Journal of Anaesthesia
Volume: 93
Issue: 3
ISSN: 0007-0912
Publisher: Oxford University Press  
Date Published: 2004-09-01
Start Page: 348
End Page: 355
Language: English
DOI: 10.1093/bja/aeh211
PROVIDER: scopus
PUBMED: 15220170
DOI/URL:
Notes: Br. J. Anaesth. -- Cited By (since 1996):9 -- Export Date: 16 June 2014 -- CODEN: BJANA -- Source: Scopus
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  1. Robert A Veselis
    98 Veselis
  2. Ruth A Reinsel
    78 Reinsel