Enhancing individual and collaborative eyewitness memory with category clustering recall

Most crimes have multiple eyewitnesses. The police typically interview co-witnesses separately. In time-sensitive investigations, this could slow down evidence accumulation. Having co-witnesses collaboratively recall a crime could potentially expedite evidence accumulation. However, past research shows that collaborative group members often have conflicting retrieval strategies that disrupt each other, degrading overall recall. This cost could potentially be overcome by aligning group members’ retrieval strategies with category clustering recall (CCR), which is a retrieval strategy where information is recalled from a series of forensically relevant categories (e.g., recalling the protagonists’ appearance, then actions). This study examined the costs and benefits of collaborative eyewitness memory by having collaborative pairs of strangers, nominal pairs (i.e., two individuals whose recall is pooled) and lone individuals watch a crime and recall it using free recall or CCR. The collaborative pairs recalled the crime faster than the nominal pairs. They also recalled more correct information than individuals but less than nominal pairs, irrespective of the retrieval method. There is therefore a speed-recall completeness trade-off when collaborative groups recall crimes. Importantly, all participants recalled more correct information when using CCR. This provides initial evidence suggesting that CCR is superior to free recall. Further research examining CCR’s benefits is recommended.     

Quality of written record following mock eyewitness testimony: Note taking should be a minimum standard!

By using a video‐based narrative (unidirectional) eyewitness statement of an alleged victim, participants were asked to imagine they were police officers. We compared the quality of mock police officer written records in a between‐subjects design comprising three conditions: (a) a free recall (n = 27), (b) a free recall by using recall strategies of the cognitive interview (n = 27), or (c) note taking while watching the video (n = 26). The quality of the reports was determined by the amount of correctly recalled details, omitted details, added details (commission errors), and changed details (confabulations). As predicted, the number of correct details was higher in the “Note Taking” condition whereas performance in the “Free Recall” and in the “Cognitive Interview” conditions did not differ. Higher verbal memory ability resulted in a better quality of the written records. Our results suggest that note taking facilitates the quality of written records.     

A meta‐analysis of the effects of acute alcohol intoxication on witness recall

There is widespread belief in the legal system that alcohol impairs witness testimony. Nevertheless, most laboratory studies examining the effects of alcohol on witness testimony suggest that alcohol may affect the number of correct but not incorrect details recalled. However, it is difficult to draw conclusions because sample sizes, testing paradigms, and recall measures vary between individual studies. We conducted a meta‐analysis to address this issue. We found alcohol intoxication had a significant and moderate sized effect on the number of correct details recalled (g = 0.40). The effect of alcohol on the number of incorrect details recalled was not significant. Further, the effect of alcohol on the recall of correct details was significantly moderated by multiple factors like intoxication level, the retention interval length between encoding and recall, and the types of questions asked (i.e., free recall vs. cued recall). We discuss the applied implications of the results.     

Cross-cultural differences in eyewitness memory reports

Increasingly, investigators conduct interviews with eyewitnesses from different cultures. The culture in which people have been socialised can impact the way they encode, remember, and report information about their experiences. We examined whether eyewitness memory reports of mock witnesses from collectivistic (sub-Saharan Africa) and individualistic (Northern Europe) cultures differed regarding quantity and quality of central and background details reported. Mock witnesses (total N = 200) from rural Ghana, urban Ghana, and the Netherlands were shown stimuli scenes of crimes in Dutch and Ghanaian settings and provided free and cued recalls. Individualistic culture mock witnesses reported the most details, irrespective of detail type. For each cultural group, mock witnesses reported more correct central details when crime was witnessed in their own native setting than a non-native setting, though for different recall domains. The findings provide insight for legal and investigative professionals as well as immigration officials eliciting memory reports in cross-cultural contexts.     

The effects of repeatedly recalling a traumatic event on eyewitness memory and suggestibility

ABSTRACT

The aims of this study were to examine the effects of repeatedly recalling a traumatic event on recall performance and eyewitness suggestibility. We also investigated whether these effects were moderated by the type of details recalled and the completeness of retrieval. Participants watched a video depicting a fatal car accident and were randomly allocated to one of four conditions in which they: (1) repeatedly recalled the traumatic (central) details of the event only (trauma-focused); (2) repeatedly recalled the non-traumatic (peripheral) details of the event only (non-trauma focused); (3) repeatedly recalled the entire video (complete); or (4) did not recall the video at all (no-recall control). Results indicated that repeated complete recall was beneficial for memory retention of the entire traumatic event and that, in general, trauma-related (central) post-event information (PEI) was less likely to be reported than trauma-unrelated (peripheral) PEI. It was also found that repeated trauma-focused recall increased trauma-related confabulations. These results not only illustrate the value of repeated complete recall to best preserve the integrity of eyewitness memory, but, perhaps more critically, warn of the dangers of repeatedly questioning witnesses specifically about the central or traumatic details of an event.     

Witnesses stumbling down memory lane: The effects of alcohol intoxication,retention interval,and repeated interviewing

Intoxicated eyewitnesses are often discredited by investigators and in court, but few studies have examined how alcohol affects witnesses’ memory. The primary aim of the present study was to examine how intoxication (alcohol vs. control), retention interval (immediate vs. one week delay), and number of interviews (one vs. two interviews) affect witnesses’ memory. The participants (N?=?99) were randomly assigned to consume either orange juice or alcohol mixed with orange juice, and they all witnessed a filmed mock crime afterwards. The recall took place either (a) immediately and after a one week delay or (b) after a one week delay only. No main effect of alcohol was found on the quantity or quality of the witnesses’ statements. Both intoxicated and sober witnesses recalled more details, and were more accurate, during immediate compared to delayed recall. For witnesses interviewed twice, an average of 30% new details were provided in the second compared to the first interview, and these were highly accurate. In sum, contrary to what one can expect, intoxicated witnesses with a low to moderate blood alcohol concentration (below 0.10%) were reliable witnesses.     

Effects of handedness consistency and saccade execution on eyewitness memory in cued- and free-recall procedures*

Identifying characteristics that distinguish between people with relatively good versus poor episodic memory is an important goal of eyewitness-memory research, as is identifying activities that can improve people’s ability to retrieve episodic memories. Consistency of hand preference is a trait associated with the quality of people’s episodic memory and repetitive saccade execution is an activity known to improve people’s ability to retrieve episodic memories. These factors were examined in relation to cued and free recall of a staged criminal event. Individuals with inconsistent hand preference (versus consistent) remembered more on a cued-recall test and also freely recalled a larger amount of victim information. Repetitive saccade execution did not increase cued recall but did increase free recall of victim information. Theoretical implications are discussed, as is potential practical significance, with an emphasis on the size of the observed effects.     

Interviewing intoxicated witnesses: Memory performance in theory and practice

Memory encoding and recall involving complex, effortful cognitive processes are impaired by alcohol primarily due to impairment of a select few, but crucial, cortical areas. This review shows how alcohol affects some, but not all, aspects of eyewitnesses' oral free recall performance. The principal results, so far, are that: a) free recall reports by intoxicated witnesses (at the investigated BAC‐levels) may contain less, but as accurate, information as reports by sober witnesses; b) immediate reports given by intoxicated witnesses may yield more information compared to reports by sober witnesses given after a one week delay; c) an immediate interview may enhance both intoxicated and sober witnesses' ability to report information in a later interview; and d) reminiscence seems to occur over repeated interviews and the new information seems to be as accurate as the previously reported information. Based on this, recommendations are given for future research to enhance understanding of the multifaceted impact of alcohol on witnesses' oral free recall of violent crimes.     

Facilitating eyewitness memory in adults and children with context reinstatement and focused meditation

This study examined the comparative efficacy of two brief techniques for facilitating eyewitness memory in police investigations. Adult and child participants (N = 126; 64 children and 62 adults) who had viewed a videotape of a crime were subsequently tested for their memory of the event following either a focused meditation procedure (FM, derived from hypnotic interviewing techniques), a context reinstatement procedure (CR, a component of the cognitive interview), or a control procedure (no memory facilitation instructions). For both adults and children, the FM and CR procedures enhanced performance on both open‐ended and closed questions to levels above those achieved by controls, although those in the CR condition produced significantly more correct responses than those in the FM condition. However, only those in the CR group displayed elevated levels of confidence in relation to incorrect responses on closed questions. Implications for the possible use of such procedures are discussed. Copyright © 2006 John Wiley & Sons, Ltd.     

And one more for the road: Commentary on the Special Issue on alcohol and eyewitness memory

Studies examining the influence of alcohol intoxication have reported mixed findings on whether it impairs eyewitness memory. Although the studies in this Special Issue investigated different questions and tested different variables, the findings of these studies collectively provide insight into mechanisms and methodological issues that may explain the ambiguous findings of alcohol intoxication and eyewitness memory. In this commentary, we first describe the experimental studies of this Special Issue. We then discuss four mechanisms that could underlie those mixed findings (alcohol myopia, disinhibition, hypervigilance, and metacognitive processes at retrieval). Last, we address methodological issues that may have contributed to those ambiguous findings (i.e., alcohol intoxication levels, automatic processing of stimuli, sensitivity of dependent variables, and possible interactions with arousal) and provide suggestions for future research to address these issues.     

Walking through doorways differentially affects recall and familiarity

Previous research has reported that walking through a doorway to a new location makes memory for objects and events experienced in the previous location less accurate. This effect, termed the location updating effect, has been used to suggest that location changes are used to mark boundaries between events in memory: memories for objects encountered within the current event are more available than those from beyond an event boundary. Within a computer‐generated memory task, participants navigated through virtual rooms, walking through doorways, and interacting with objects. The accuracy and their subjective experience of their memory for the objects (remember/know and confidence) were assessed. The findings showed that shifts in location decreased accurate responses associated with the subjective experience of remembering but not those associated with the experience of knowing, even when considering only the most confident responses in each condition. These findings demonstrate that a shift in location selectively impacts recollection and so contributes to our understanding of boundaries in event memory.     

Effects of cannabis on eyewitness memory: A field study

Eyewitnesses to crimes are regularly under the influence of drugs, such as cannabis. Yet there is very little research on how the use of cannabis affects eyewitness memory. In the present study, we assessed the effects of cannabis on eyewitness recall and lineup identification performance in a field setting. One hundred twenty visitors of coffee shops in Amsterdam viewed a videotaped criminal event, were interviewed about the event, and viewed a target‐present or target‐absent lineup. Witnesses under the influence of cannabis remembered significantly fewer correct details about the witnessed event than did sober witnesses, with no difference in incorrect recall. Cannabis use was not significantly associated with lineup identification performance, but intoxicated witnesses were significantly better at judging whether their lineup identification was accurate. Theoretical and practical implications of the findings are discussed.     

Children's recall and source monitoring of a repeated event using a timeline as an interview aid

Investigators sometimes use timelines (visual depictions of time) to help children identify temporal information from experienced events or details from a particular instance of a repeated event. However, little is actually known about the efficacy of this visual aid on children's memories. Six‐ to 9‐year‐olds participated in four occurrences of a repeated event and were later interviewed with or without the use of a timeline. Children in the timeline condition were less accurate and made more source‐monitoring errors than those in the control condition. For items that appeared consistently throughout the events, a suggestibility effect was more evident for older children who used the timeline than those who did not. Overall, there was no clear evidence in support of the visual aid. Despite its popularity, our findings suggest that timelines should be further examined to establish whether, and under what circumstances, they might be used in investigative contexts.     

Conflict and metacognitive control: the mismatch-monitoring hypothesis of how others' knowledge states affect recall

Information about others' success in remembering is frequently available. For example, students taking an exam may assess its difficulty by monitoring when others turn in their exams. In two experiments, we investigated how rememberers use this information to guide recall. Participants studied paired associates, some semantically related (and thus easier to retrieve) and some unrelated (and thus harder). During a subsequent cued recall test, participants viewed fictive information about an opponent's accuracy on each item. In Experiment 1, participants responded to each cue once before seeing the opponent's performance and once afterwards. Participants reconsidered their responses least often when the opponent's accuracy matched the item difficulty (easy items the opponent recalled, hard items the opponent forgot) and most often when the opponent's accuracy and the item difficulty mismatched. When participants responded only after seeing the opponent's performance (Experiment 2), the same mismatch conditions that led to reconsideration even produced superior recall. These results suggest that rememberers monitor whether others' knowledge states accord or conflict with their own experience, and that this information shifts how they interrogate their memory and what they recall.     

Walking through doorways causes forgetting: recall

The aim of the current study was to explore how the location updating effect is affected when people are tested using recall rather than recognition, which is what has been done in prior work. Differences in the memory processes involved with these two tasks lead to predictions for two different patterns of data. In Experiment 1, memory was tested by having participants recall the single object they were carrying or had just put down, whereas in Experiment 2, people sometimes needed to recall both objects. It was found that, unlike recognition test performance, a similar location updating effect was found for both Associated (what was currently being carried) and Dissociated (what was recently set down) objects. Moreover, when both objects were correctly recalled, there was a bias to remember them in the order that they were encountered. Finally, if only one object was correctly recalled, it was the Associated object that was currently being carried. Overall, these results are consistent with the Event Horizon Model of event cognition.     

Mood and recall of autobiographical memory: the effect of focus of self-knowledge

Mood state facilitates recall of affectively congruent memories (i.e., mood-congruent recall). Mood state may also promote motivation to alleviate a negative affective state, leading to retrieval of affectively incongruent memories (i.e., mood incongruent recall). The present study demonstrates that the focus of self-knowledge influences the occurrence of both mood-congruent recall and mood-incongruent recall. Three experiments found that mood-congruent recall occurred when participants recalled their experiences from a self-aspect that was related to the elicitor of moods, whereas mood-incongruent recall occurred when they recalled their experiences from a self-aspect that was unrelated to the elicitor of moods. These results suggest that the nature of the self-aspect from which persons recall their experiences determines whether mood-congruent or mood-incongruent recall occurs.     

Mood and memories of parental rearing styles: A comparison of mood effects on questionnaire-cued and free recall of autobiographical memories

The relationship between memories of childhood experiences (e.g., adverse parenting) and adult depression often found raises questions of interpretation. On the one hand, both laboratory studies and clinicians' experiences suggest that subjects in a depressed mood frequently show a negative bias in perceptions and memories. Negative childhood memories in depressed persons might, therefore, be interpreted as epiphenomena of depressed mood instead of etiological factors. On the other hand, memories of childhood experiences seem remarkably stable across changes in depressed mood, especially when memories are elicited by means of standardized questionnaires. In the mood and memory literature several explanations for this stability are offered. For one thing, highly structured cues to elicit memories (such as in questionnaires) are hypothesized to be less susceptible to mood bias than unstructured memory cues (such as in free recall procedures). On the other hand, resource allocation theorists suggest that childhood memories, being well established and rehearsed, are relatively impervious to mood bias no matter how they are elicited. In this study we examined whether different methods of eliciting childhood memories (i.e., free recall and questionnaire-cued) are differentially susceptible to mood bias. To this aim, we used a mood induction procedure to induce depressed, neutral, and elated mood and assessed childhood memories both before and after the mood induction using both questionnaires and free recall to elicit memories. Results suggested that memories elicited by means of free recall as well as by means of questionnaire-cued recall were susceptible to depressed and elated mood bias. The implications for research addressing the link between childhood experiences and depression are discussed.