The effects of acute alcohol intoxication on the cognitive mechanisms underlying false facial recognition

The influence of acute alcohol intoxication and hair visibility on delayed face recall

Many witnesses are intoxicated at crime scenes, yet little is known of their ability to accurately describe perpetrators to police. We therefore explored the impact of alcohol on delayed verbal face recall across two experiments. Participants were administered an alcoholic or non-alcoholic beverage prior to viewing either one or two unfamiliar female faces, which they described from memory the following day while in a sober state. Each to-be-remembered model had long hair worn either loose (i.e., visible), or tied behind the head (i.e., concealed). Testing the hypothesis that alcohol narrows the focus of attention to the external (hairstyle) region of faces, we expected intoxicated participants to have poorer memory of internal face features (eyes, nose, mouth) than sober controls for stimulus faces with visibly long hair. Results revealed poorer recall accuracy for internal face details following alcohol consumption (Exp. 2), but the effect was uninfluenced by hairstyle. Findings are therefore consistent with the more general view that alcohol is associated with a bias to the external (hairstyle) region of faces during face learning, irrespective of hair visibility.

The acute effects of alcohol on social cognition: A systematic review of experimental studies

RATIONALE

Alcohol effects on social cognition have been studied by measuring facial emotion recognition, empathy, Theory of Mind (ToM) and other forms of information processing.

OBJECTIVES

Using the PRISMA guidelines, we reviewed experimental studies that examined acute effects of alcohol on social cognition.

METHODS

Scopus, PsycInfo, PubMed, and Embase were searched between July 2020 - January 2023. The PICO strategy was used for identifying participants, interventions, comparators, and outcomes. Participants (N = 2330) were adult social alcohol users. Interventions consisted of acute alcohol administration. Comparators included placebo or the lowest alcohol dose. Outcome variables were grouped into three themes: facial processing, empathy and ToM, and perceptions of inappropriate sexual behavior.

RESULTS

A total of 32 studies were reviewed. Studies measuring facial processing (67%) often found no effects of alcohol on the recognition of specific emotions, facilitated emotion recognition at lower doses and worsened emotion recognition at higher doses. In studies measuring empathy or ToM (24%), lower doses were more likely to lead to improvements while higher doses were generally impairing. Within the third group of studies (9%), moderate to high alcohol doses made it more difficult to perceive sexual aggression accurately.

CONCLUSIONS

Lower alcohol doses might sometimes help facilitate social cognition, but most data were in line with the idea that alcohol tends to worsen social cognition, particularly at higher doses. Future studies might focus on examining other moderators of the effects of alcohol on social cognition, particularly interpersonal characteristics such as trait emotional empathy, and participant and target gender.

The impact of post-encoding alcohol consumption on episodic memory recall and remember-know responses in heavy drinkers

Introduction

People often consume alcohol following trauma, particularly in response to distressing memories. To date, little is known about how post-encoding alcohol consumption influences episodic memory recall for negative events. Understanding these effects may help to improve support for trauma victims - for example, witnesses and victims of crimes.

Methods

We tested 60 participants who self-described as heavy drinkers. After watching an analog trauma film, half were allocated to consuming a moderate dose of alcohol (Alcohol-Exposed group), while half received a placebo drink (Placebo-Control group). Immediately and after a one-week delay, participants recalled the event via free and cued recall tasks. Participants also gave remember-know responses and confidence ratings, elucidating alcohol's effect on experiential memory.

Results

Free recall performance was similar for the Alcohol-Exposed group and the Placebo-Control group during Sessions 1 and 2. The Alcohol-Exposed group benefitted more from the delayed repeated retrieval attempt. For the cued recall task, the Alcohol-Exposed group provided more "Do not Know" responses compared to the Placebo-Control group in both sessions. For the Alcohol-Exposed group only "Correct Know" responses increased from Session 1 to 2. Although memory performance improved across sessions, confidence levels decreased from Session 1 to 2 in the Alcohol-Exposed group.

Discussion

Post-encoding alcohol consumption appears to impact immediate episodic memory retrieval; however, this effect is only temporary in nature. No evidence was found that alcohol primarily reduces remembering responses. Much like previous findings focusing on pre-encoding alcohol consumption (Hagsand et al., 2017), current findings suggest that providing individuals who drank alcohol after witnessing an incident with a delayed repeated retrieval attempt can lead to more complete and accurate testimonies.

A Longitudinal Examination of Alcohol-Related Blackouts as a Predictor of Changes in Learning, Memory, and Executive Function in Adolescents

INTRODUCTION

In adolescents, the relationship between alcohol-related blackouts (ARBs) and distinct cognitive changes lasting beyond intoxication is unclear. We examined ARBs as a predictor of persistent changes in the development of learning, memory, and executive function in participants from the National Consortium on Alcohol and Neurodevelopment in Adolescence (NCANDA) study.

METHODS

Descriptive analyses of the NCANDA sample (N = 831, 50.9% female, 12-21 years at baseline) identified ARB patterns within participants with an ARB history (n = 106). Latent growth curve modeling evaluated ARB-related performance changes on four neuropsychological measures across five years, excluding baseline data to reduce the magnitude of practice effects over time (n = 790). Measures included the Penn Conditional Exclusion Test (PCET), Penn Letter N-back Test (PLBT), Penn Facial Memory Test immediate (PFMT_i), and delayed (PFMT_d) recognition trials, and the Rey Complex Figure Test copy (RCFT_c), immediate recall (RCFT_i), and delayed recall (RCFT_d) trials. Multivariate models were fit for raw accuracy scores from each measure, with ARB history (i.e., presence of past-year ARBs) as the main independent variable. Age, sex, race, socioeconomic status, assessment site, and alcohol use (i.e., past-year frequency) were included as covariates. Interaction effects between ARB history and alcohol use frequency were tested.

RESULTS

By year five, 16% of participants had experienced at least one ARB (59% of whom reported > 1 ARB and 57% of whom had an ARB lasting > 1 h). After controlling for demographics and alcohol use, ARB history predicted attenuated PFMT_d performance growth at year one. Interaction effects between ARB history and alcohol use frequency predicted attenuated PFMT_d performance growth at years one and two. ARB history predicted attenuated RCFT_i and RCFT_d performance growth by year four, but not PCET or PLBT performance over time. By contrast, greater past-year alcohol use predicted attenuated PFMT_i and PFMT_d performance growth between years two and four in adolescents without an ARB history.

CONCLUSION

We found that ARBs predict distinct, lasting changes in learning and memory for visual information, with results suggesting that the developing brain is vulnerable to ARBs during adolescence and emerging adulthood.

Alcohol myopia and the distracting effects of hair in face recognition

BACKGROUND

According to alcohol myopia theory, alcohol reduces cognitive resources and restricts the drinker's attention to only the more prominent aspects of a visual scene. As human hairstyles are often salient and serve as important facial recognition cues, we consider whether alcohol restricts attention to this region of faces upon initial viewing.

AIMS

Participants with higher breath alcohol concentrations just prior to encoding a series of unfamiliar faces were expected to be poorer than more sober counterparts at recognising the internal but not external features of those faces at test.

METHODS

Drinkers in a nearby bar (n=76) were breathalysed and then shown a sequence of 21 full face photos. After a filled five-minute retention interval they completed a facial recognition task requiring them to identify the full, internal or external region of each of these among a sequence of 21 previously unseen (part or whole) faces.

RESULTS

As predicted, higher breath concentrations were associated with poorer discrimination of internal but not external face regions.

CONCLUSIONS

Our findings suggest that alcohol restricts unfamiliar face encoding by narrowing the scope of attention to the exterior region of unfamiliar faces. This has important implications for drunk eyewitness accuracy, though further investigation is needed to see if the effect is mediated by gender, hair length and face feature distinctiveness.

Do intoxicated witnesses produce poor facial composite images?

RATIONALE

The effect of alcohol intoxication on witness memory and performance has been the subject of research for some time, however, whether intoxication affects facial composite construction has not been investigated.

OBJECTIVES

Intoxication was predicted to adversely affect facial composite construction.

METHODS

Thirty-two participants were allocated to one of four beverage conditions consisting of factorial combinations of alcohol or placebo at face encoding, and later construction. Participants viewed a video of a target person and constructed a composite of this target the following day. The resulting images were presented as a full face composite, or a part face consisting of either internal or external facial features to a second sample of participants who provided likeness ratings as a measure of facial composite quality.

RESULTS

Intoxication at face encoding had a detrimental impact on the quality of facial composites produced the following day, suggesting that alcohol impaired the encoding of the target faces. The common finding that external compared to internal features are more accurately represented was demonstrated, even following alcohol at encoding. This finding was moderated by alcohol and target face gender such that alcohol at face encoding resulted in reduced likeness of external features for male composite faces only.

CONCLUSIONS

Moderate alcohol intoxication impairs the quality of facial composites, adding to existing literature demonstrating little effect of alcohol on line-up studies. The impact of intoxication on face perception mechanisms, and the apparent narrowing of processing to external face areas such as hair, is discussed in the context of alcohol myopia theory.

The Effects of Alcohol Intoxication on Accuracy and the Confidence-Accuracy Relationship in Photographic Simultaneous Line-ups

Acute alcohol intoxication during encoding can impair subsequent identification accuracy, but results across studies have been inconsistent, with studies often finding no effect. Little is also known about how alcohol intoxication affects the identification confidence-accuracy relationship. We randomly assigned women (N = 153) to consume alcohol (dosed to achieve a 0.08% blood alcohol content) or tonic water, controlling for alcohol expectancy. Women then participated in an interactive hypothetical sexual assault scenario and, 24 hours or 7 days later, attempted to identify the assailant from a perpetrator present or a perpetrator absent simultaneous line-up and reported their decision confidence. Overall, levels of identification accuracy were similar across the alcohol and tonic water groups. However, women who had consumed tonic water as opposed to alcohol identified the assailant with higher confidence on average. Further, calibration analyses suggested that confidence is predictive of accuracy regardless of alcohol consumption. The theoretical and applied implications of our results are discussed.