Memory encoding and retrieval on the ascending and descending limbs of the blood alcohol concentration curve.
BACKGROUND
Little is known about acute effects of alcohol on memory encoding and retrieval on different limbs (ascending and descending) of the blood alcohol concentration (BAC) curve.


OBJECTIVE
This extensive experiment was designed to examine alcohol's effects on memory encoding and retrieval throughout a protracted drinking episode.


METHODS
In a 9-h session, male participants consumed either alcohol (1 ml/kg) or placebo (n = 32/32) over a period of 90 min and learned various materials in different memory tasks before, during, and after consuming the drinks, while their BAC levels were monitored. A week later, in a similar session, they were tested on learned materials before, during, and after drinking. Mood was assessed throughout both sessions.


RESULTS
Alcohol impaired recall of words more than recognition, and cued recall most severely. Perceptual priming and picture recognition were not affected by alcohol. Alcohol impaired encoding in cued recall, recognition of completed word fragments, and free recall regardless of limb, but impaired retrieval in word recognition only during the ascending BAC. Alcohol increased negative mood on the descending limb during the first session, and on the ascending limb during the second session.


CONCLUSIONS
Under naturalistic drinking conditions, alcohol's effects on memory depend on task, memory process, and limb of the BAC curve. The differential effects of alcohol on retrieval during the ascending and descending limbs demonstrate the importance of examining the differential effects on the two limbs.
Söderlund
Hedvig
H
The Rotman Research Institute, Baycrest Centre for Geriatric Care, Toronto, ON, M6A 2E1, Canada. hedvig@rotman-baycrest.on.ca
Parker
Elizabeth S
ES
Schwartz
Barbara L
BL
Tulving
Endel
E
D000328:Adult; D003463:Cues; D000431:Ethanol / Q000097:blood* / Q000494:pharmacology*; D006801:Humans; D008297:Male; D008568:Memory / Q000187:drug effects*; D011939:Mental Recall / Q000187:drug effects
D000431:Ethanol