People with ASD may be over-represented in the Criminal Justice System, as a victim, witness, or perpetrator of a crime. Several studies have now explored eyewitness testimony in ASD (see Maras & Bowler, in press). None, however, have used a live eyewitness event in which the witness actively participated.
Typical individuals’ memory is better for actions that are self-performed than actions observed being performed by another person. Several researchers have reported this “self-enactment effect” to be diminished or absent in ASD, however findings are inconsistent (see Lind, 2010).
To use a live eyewitness scenario to examine:
1) How well adults with ASD recall a participated-in eyewitness event.
2) Whether witnesses with ASD show a self-enactment effect
3) Whether they show impaired source monitoring for who performed which actions.
Eighteen adults with ASD and 18 age- and IQ-matched (mean VIQ=110.86) comparisons participated in a live scripted eyewitness scenario whereby they assisted the experimenter perform first aid on a manikin-victim. There were 19 actions that the experimenter always performed and 19 that the participant always performed. One hour later participants provided their free recall (FR) account of this, before answering specific questions.
Groups did not differ in the number of correct details reported in both FR and questioning phases (all Fs<.79, ps>.38, ηp²s<.02), however the ASD group made significantly more errors than their comparisons in both phases (all Fs>4.20, ps<.05, ηp²s> 11).
There was a main effect of detail type for self- versus other-performed actions, F(1,34)=105.54, p<.001, ηp²=.76, but no group x detail type interaction, F(1,34)=1.44, p=.24, ηp²=.04.
The ASD group made significantly more ‘Self’ source errors (incorrectly attributing self-performed actions as having been performed by the experimenter) than the comparison group in their FR, F=15.87, p<.001, ηp²=.32, but not questioning, F(1,34)=.54, ηp²=.02. Groups did not differ in 'Other' errors in either phase, Fs<.98, ps>.33, ηp²s<.03.
Overall findings indicate forensically that witnesses, victims or suspects with ASD may recall just as many correct details as their typical counterparts, but that investigators might seek to verify the veracity of details.
Both groups showed a self-enactment effect in both interview phases. Theoretically this indicates that individuals with ASD lay down a stronger memory trace for self-performed actions. Forensically it indicates that if an individual with ASD is involved in a crime they will be able to recall what they did.
The ASD group made more source confusions in FR (but not in questioning) in attributing actions that they had actually performed themselves as having been performed by the experimenter. Whilst ASD witnesses appear to lay down a stronger memory trace to recall more self-performed actions, they are also more likely to confuse their source. Difficulties in executive functioning (see Hill, 2004) might trigger pronoun reversal/confusion (e.g., Williams et al., 2011) in FR that, in line with the task support hypothesis (Bowler et al., 2004), are diminished with questioning. This has implications for forensic interviewing; witnesses with ASD may benefit from more specific direction in interviews to focus their recall.
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