Intoxicated Witnesses Flashcards
what is the UK drink drive limit
80mg of alcohol per 100ml of blood
35mg per 100ml of breath
Soderlund
the effect of alcohol on cognition depends on the different points on the Blood Alcohol Concentration Curve.
Ascending limb- memory, reasoning and information processing impaired here.
Descending limb- executive function, visual memory impaired here.
Institute of Alcohol Studies
In 2015/2016 in England, victims believed the offenders to be under the influence of alcohol in 39% of all violent incidents
Crossland, Kneller & Wilcock
Survey of 198 English police officers found that 43.96% of interviews with witnesses were intoxicated at the time of the crime
Evans,
Officers interviewed an average of 4 intoxicated witnesses a week
53% of officers surveyed, routinely dealt with intoxicated witnesses and suspects
Crossland
police believe that statements provided by intoxicated witnesses to be significantly less accurate
Crossland, Kneller & Wilcock; Submitted
240 jury eligible individuals completed an online questionnaire rating one of six witness testimonies given when either sober, moderately or severely intoxicated.
Within each condition, the testimony was either long or short.
50% were told the state of the witness, 50% were not.
Knowledge of the witness’s intoxication and a less complete account led to lower credibility ratings.
White
alcohol reduces the ability to form new long term memories
Parker
alcohol impairs encoding/storage more than retrieval
Steele and Josephs
Alcohol Myopia Theory
alcohol Myopia Theory
to explain alcohol’s dissociative effects on an individuals recall in similar situations
the theory proposes a disproportionate amount of attention is given to central salient cues, whilst weaker more peripheral cues receive less attention
Explain the assumptions of AMT
when drunk we attend to, and encode fewer available cues
Alcohol reduces our ability to process and extract meaning from the cues and information we do perceive
inhibitory cues are less salient
Evaluate AMT
research supports attention allocation model in explaining the social behaviour of intoxicated people
no detailed account of the cognitive mechanism underpinning the myopic effect
it is not clear whether alcohol reduces the overall capacity of one’s attention or whether it hampers our ability to allocate attention
Yuille
witnessed a staged theft
50% of witnesses provided immediate and delayed recall,
50% just delayed
intoxicated resulted in significant reduction in overall reliability
intoxication exhibited a deficit in recall in both immediate and delayed
no effect on ID accuracy in TP
increased in false ID in TA
Dysart;
field study
103 participants approached by female recruiter
in TP Blood Alcohol Level had no effect
in TA intoxicated were less likely to correctly identify
Schreiber-Compo 1
participants interacted with a bar-tender whilst either sober, intoxicated, placebo
immediately after convo participants completed free recall
central details; descriptions of bartender, actions, convo as accurate
peripheral details significantly less accurate
Provides support for AMT
Schreiber-Compo 2
examined effects of alcohol on susceptibility to misinformation
participants interacted with a bar-tender whilst either sober, intoxicated, placebo
during free recall task misinformation was introduced
in an interview significantly more incorrect details reported when misinformation introduced for all intoxication levels
Harvey, Kneller & Campbell
used eye tracking to provide measures of overt visual attention in sober and drunk participants as they encoded photographic images of genuine crime scenes
its a direct test of AMT
after 24 hours memory tested
centre of images attracted more attention then periphery
alcohol narrowed eye movements it made no sig diff to memory
Harvey, Kneller
used static images of a forensically relevant event
combined face identification task with recognition memory test
alcohol reduced eye movements but no less information gathering
more likely to correctly reject TA than correctly ID from TP
significant negative effect of alcohol on recognition
contrary to AMT no difference in peripheral memory
Crossland, Kneller, Wilcock
conducted two lab based studies
study 1- intoxication found no significant reduction in accuracy using either free recall or recognition tests
study 2- high blood alcohol content impaired recall when memory assessed through free recall but not recognition
Altman
examined memory for a video crime from bar customers
interviewed immediately after seeing video
alcohol negatively affected both quantity and quality of recall
Griffin 2010
reviewed AMT in examining consumption and high risk sexual behaviour amongst US female college students
Macdonald
applied AMT to risky sexual behaviour
intoxicated people will
be more or less likely to exhibit risky behavior, depending on the cues provided. In 4 studies, we found
an interaction between intoxication and cue type. When impelling cues were present, intoxicated people
reported greater intentions to have unprotected sex than did sober people. When subtle inhibiting cues
were present, intoxicated and sober people reported equally cautious intentions
