Alcohol-induced retrograde facilitation renders witnesses of crime less suggestible to misinformation

RATIONALE: Research has shown that alcohol can have both detrimental and facilitating effects on memory: intoxication can lead to poor memory for information encoded after alcohol consumption (anterograde amnesia) and may improve memory for information encoded before consumption (retrograde facilitation). This study examined whether alcohol consumed after witnessing a crime can render individuals less vulnerable to misleading post-event information (misinformation). METHOD: Participants watched a simulated crime video. Thereafter, one third of participants expected and received alcohol (alcohol group), one third did not expect but received alcohol (reverse placebo), and one third did not expect nor receive alcohol (control). After alcohol consumption, participants were exposed to misinformation embedded in a written narrative about the crime. The following day, participants completed a cued-recall questionnaire about the event. RESULTS: Control participants were more likely to report misinformation compared to the alcohol and reverse placebo group. CONCLUSION: The findings suggest that we may oversimplify the effect alcohol has on suggestibility and that sometimes alcohol can have beneficial effects on eyewitness memory by protecting against misleading post-event information

Do intoxicated witnesses produce poor facial composite images?

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. Intoxication was predicted to adversely affect facial composite construction. 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. 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. 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

Evidence-Based Investigative Interviewing : Applying Cognitive Principles

https://digitalcommons.montclair.edu/all_books/1368/thumbnail.jp

Alcohol intoxication impairs eyewitness memory and increases suggestibility: Two field studies

Two field studies tested the effect of alcohol intoxication on memory for a live interaction at immediate, delayed, and repeated testing. In Study 1 (N=86), one researcher presented bar tenants with (misleading) questions regarding a preceding interaction with another researcher. One week later, participants' memory was tested again. Study 2 (N=189) added a delayed-testing only condition. We hypothesized intoxication to impair memory and enhance suggestibility and explored whether time of testing affected the outcome on these variables. In Study 1, intoxication reduced completeness and increased suggestibility. In Study 2, intoxication reduced completeness and increased suggestibility in delayed-only and repeated testing, compared with immediate testing. Sober participants benefited from repeated testing in Study 2, but not Study 1. Findings lend support for consolidation and decay theory and suggest that immediate (intoxicated) testing is preferable over delayed-only testing. Findings provide little support for alcohol myopia theory.</p