The Elusive Effects of Alcohol Intoxication on Visual Attention and Eyewitness Memory

Abstract

Alcohol is a contributing factor in many crimes, yet little is known of its effects on eyewitness memory and face identification. Some authors suggest that intoxication impairs attention and memory, particularly for peripheral scene information, but the data supporting this claim are limited. The present study therefore sought to determine whether (i) intoxicated participants spend less time fixating on peripheral regions of crime images than sober counterparts, (ii) whether less information is recognised from image regions receiving fewer gaze fixations and (iii) whether intoxicated participants are less able to identify the perpetrator of a crime than sober participants. Contrary to expectations, participants' ability to explore and subsequently recognise the contents of the stimulus scenes was unaffected by alcohol, suggesting that the relationship between intoxication, attention and eyewitness memory requires closer scrutiny.

The influence of alcohol and weapon presence on eyewitness memory and confidence

“…The hypotheses we tested with this procedure, which closely replicated that of Loftus et al (1987), are as follows. In line with previous alcohol and eyewitness memory studies, participants were (a) expected to show greater memory accuracy for questions related to central scene features concerning the target male and his exchange with the assistant, relative to peripheral scene features (Crossland et al, 2016;Harvey et al, 2013aHarvey et al, , 2013bSchreiber Compo et al, 2011). (b) Those shown the weapon scene were expected to respond less accurately to the memory questionnaire than no-weapon controls (Loftus et al, 1987).…”

“…A further problem with our study and one that affects numerous similar studies (e.g., Hagsand et al, ; Hagsand, Roos af Hjelmsäter, Granhag, Fahlke, & Söderpalm‐Gordh, ; Harvey et al, , ; Schreiber Compo et al, ) is that our central stimulus classification was not objectively defined. Although few would argue that the armed assailant is not the “central” feature of our weapon scene, his semantic salience is confounded by his spatial positioning near the centre of the display.…”

“…Carlson et al found that witnesses of an armed mock crime showed closer alignment between identification confidence and accuracy than no‐weapon controls, which may reflect a metacognitive awareness that weapons are a distraction, with confidence downgraded accordingly. The effect of alcohol on eyewitness confidence and identification accuracy has also received little attention beyond the observation that alcohol tends generally to lower memory confidence (e.g., Harvey et al, ). One exception is a study by Flowe et al (), who looked specifically at the effect of alcohol on the CA relationship in an eyewitness context but found it had no influence.…”

“…Furthermore, following a meta-analysis of the alcohol and scene recall literature, Jores et al (2019) found only small adverse effects of low to moderate alcohol doses on the completeness of recall, but larger impairments to both recall completeness and accuracy at higher doses (BAC ≥ 0.10%). This perhaps explains why null effects of alcohol on scene memory are commonly reported in lab studies which, for ethical reasons, rarely elicit BACs above 0.10% (e.g., Hagsand et al, 2017;Harvey, Kneller, & Campbell, 2013b;Hildebrand Karlén, Roos af Hjelmsäter, Fahlke, Granhag, & Söderpalm-Gordh, 2017;Schreiber Compo et al, 2012).…”

“…The effect of alcohol on eyewitness confidence and identification accuracy has also received little attention beyond the observation that alcohol tends generally to lower memory confidence (e.g., Harvey et al, 2013b). One exception is a study by Flowe et al (2017), who looked specifically at the effect of alcohol on the CA relationship in an eyewitness context but found it had no influence.…”