Alcohol and Memory (non-blackout)

The acute effects of alcohol on memory: A review of laboratory studies in healthy adults.
Mintzer, Miriam Z.
International Journal on Disability and Human Development. (Jan 1, 2007) Vol 6, Iss 4, pages 397-404.
Abstract:
Given the widespread use of alcohol in society, research on the effects of alcohol on memory has important clinical utility. In addition, investigation of the amnesia produced by alcohol can be a powerful tool for elucidating normal and abnormal memory mechanisms. The purpose of this paper was to provide a review of placebo-controlled laboratory studies of the acute effects of alcohol administration on memory in healthy adult social drinkers. Acute alcohol administration impairs working memory, episodic memory, and semantic memory but does not appear to impair implicit memory or automatic, non-conscious memory processes. Alcohol produces relatively greater impairment of episodic memory encoding than retrieval processes. Whereas episodic memory is impaired following acute alcohol administration (anterograde amnesia), episodic memory for information presented prior to alcohol administration is enhanced under certain conditions (retrograde facilitation). Although extensive research has been conducted on the acute effects of alcohol on memory, many interesting questions surrounding the effects of alcohol on memory (e.g., the selectivity of alcohol’s effects on different working memory processes; the conditions under which episodic memory retrieval is impaired; the mechanisms underlying retrograde facilitation; the effects of ascending versus descending blood levels on different memory processes), as well as the relationship between memory effects and emotion/mood, remain to be explored. Further hypothesis-driven memory research with alcohol using behavioral and neuroimaging techniques has the potential both to enhance the understanding of the clinical implications of alcohol use and to elucidate basic cognitive and brain mechanisms.

Memory encoding and retrieval on the ascending and descending limbs of the blood alcohol concentration curve.
Söderlund, Hedvig, et. al.
Psychopharmacology, Vol 182(2), Oct, 2005. pp. 305-317.
Abstract:
Rationale: 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. Objectives: 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.

Acute alcohol effects on repetition priming and word recognition memory with equivalent memory cues.
Ray, Suchismita, et. al.
Brain and Cognition, Vol 60(2), Mar, 2006. pp. 118-127.
Abstract:
Acute alcohol intoxication effects on memory were examined using a recollection-based word recognition memory task and a repetition priming task of memory for the same information without explicit reference to the study context. Memory cues were equivalent across tasks; encoding was manipulated by varying the frequency of occurrence (FOC) of words in the study lists. Twenty-two female and male social drinkers (age 21-24 years) completed equivalent versions of the memory tasks in two counterbalanced sessions (alcohol challenge, no-alcohol). Alcohol and the FOC manipulation affected recollection-based memory processing, but not repetition priming. Results supported alcohol’s dissociative effects on memory systems.

Acute effects of alcohol on encoding and consolidation of memory for emotional stimuli.
Weafer, Jessica, et. al.
Journal of Studies on Alcohol; Quarterly Journal of Studies on Alcohol
Abstract:
Objective: Acute doses of alcohol impair memory when administered before encoding of emotionally neutral stimuli but enhance memory when administered immediately after encoding, potentially by affecting memoryconsolidation. Here, we examined whether alcohol produces similar biphasic effects on memory for positive or negative emotional stimuli. Method: The current study examined memory for emotional stimuli after alcohol (0.8 g/kg) was administered either before stimulus viewing (encoding group; n = 20) or immediately following stimulus viewing (consolidation group; n = 20). A third group received placebo both before and after stimulus viewing (control group; n = 19). Participants viewed the stimuli on one day, and their retrieval was assessed exactly 48 hours later, when they performed a surprise cued recollection and recognition test of the stimuli in a drug-free state. Results: As in previous studies, alcohol administered before encoding impaired memory accuracy, whereas alcohol administered after encoding enhanced memory accuracy. Critically, alcohol effects on cued recollection depended on the valence of the emotional stimuli: Its memory-impairing effects during encoding were greatest for emotional stimuli, whereas its memory-enhancing effects during consolidation were greatest for emotionally neutral stimuli. Effects of alcohol on recognition were not related to stimulus valence. Conclusions: This study extends previous findings with memory for neutral stimuli, showing that alcohol differentially affects the encoding and consolidation of memory for emotional stimuli. These effects of alcohol on memory for emotionally salient material may contribute to the development of alcohol-related problems, perhaps by dampening memory for adverse consequences of alcohol consumption.