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.     

Misleading postevent information and working memory capacity: an individual differences approach to eyewitness memory

The present study examines how individual differences in working memory capacity relate to the effect of misleading postevent information on memory for the original event. Participants were shown a film of a crime event and were then asked to unscramble a narrative that included misinformation regarding some of the film's details. Additionally, the working memory capacity of the participants was measured using the operation‐word span task. Finally, in a free recall test, participants recalled fewer correct details in the misinformation condition compared to the control condition. This effect was negatively correlated with working memory capacity. Copyright © 2002 John Wiley & Sons, Ltd.     

Recalling a Witnessed Event Increases Eyewitness Suggestibility: The Reversed Testing Effect

ABSTRACT— People's later memory of an event can be altered by exposure to misinformation about that event. The typical misinformation paradigm, however, does not include a recall test prior to the introduction of misinformation, contrary to what real-life eyewitnesses encounter when they report to a 911 operator or crime-scene officer. Because retrieval is a powerful memory enhancer (the testing effect), recalling a witnessed event prior to receiving misinformation about it should reduce eyewitness suggestibility. We show, however, that immediate cued recall actually exacerbates the later misinformation effect for both younger and older adults. The reversed testing effect we observed was based on two mechanisms: First, immediate cued recall enhanced learning of the misinformation; second, the initially recalled details became particularly susceptible to interference from later misinformation, a finding suggesting that even human episodic memory may undergo a reconsolidation process. These results show that real-life eyewitness memory may be even more susceptible to misinformation than is currently envisioned.     

Emotional arousal and memory: a test of the poststimulus processing hypothesis

Emotional arousal is believed to enhance memory for details central to an episode but impair memory for peripheral details. However, new research suggests that arousal induced thematically (i.e., through involvement with an unfolding event) produces only memory enhancements. This article examines whether consciously controlled elaborative processing in the aftermath of an arousing experience is responsible. A dual task manipulation was used to prevent participants from ruminating over a video that depicted an abduction and attack. Several indices of recall showed greater memory for emotional event details than for details from a neutral control video, which remained the case when the opportunity for post-stimulus elaboration was prevented. Thus, superior retention of the content of emotional experiences may arise from the way in which arousal is induced rather than through immediate postevent cognitions.     

Individual differences in visual imagery determine how event information is remembered

Individuals differ in how they mentally imagine past events. When reminiscing about a past experience, some individuals remember the event accompanied by rich visual images, while others will remember it with few of these images. In spite of the implications that these differences in the use of imagery have to the understanding of human memory, few studies have taken them into consideration. We examined how imagery interference affecting event memory retrieval was differently modulated by spatial and object imagery ability. We presented participants with a series of video-clips depicting complex events. Participants subsequently answered true/false questions related to event, spatial, or feature details contained in the videos, while simultaneously viewing stimuli that interfered with visual imagery processes (dynamic visual noise; DVN) or a control grey screen. The impact of DVN on memory accuracy was related to individual differences in spatial imagery ability. Individuals high in spatial imagery were less accurate at recalling details from the videos when simultaneously viewing the DVN stimuli compared to those low in spatial imagery ability. This finding held for questions related to the event and spatial details but not feature details. This study advocates for the inclusion of individual differences when studying memory processes.     

Two Types of Conditioned Reflex and a Pseudo Type

Although it is widely known that memory is enhanced when encoding and retrieval occur in the same state, the impact of elevated stress/arousal is less understood. This study explores mood-dependent memory's effects on visual recognition and recall of material memorized either in a neutral mood or under higher stress/arousal levels. Participants’ (N = 60) recognition and recall were assessed while they experienced either the same or a mismatched mood at retrieval. The results suggested that both visual recognition and recall memory were higher when participants experienced the same mood at encoding and retrieval compared with those who experienced a mismatch in mood context between encoding and retrieval. These findings offer support for a mood dependency effect on both the recognition and recall of visual information.     

Memory for memory

Participants read short passages and 1 day later they answered questions via telephone about the passages (text facts) and about the experimental session (event facts). They were telephoned again 6 weeks later and answered the same questions about text and event facts. They also answered new questions about whether they remembered the answers they had given in the initial telephone interview (recall for prior memory performance). Although participants accurately remembered the majority of past memory successes, they were poor at remembering past memory failures. After being provided with the correct answer and tested again, the participants' performance improved somewhat, especially for memory failures. This suggests that some errors in recalling past forgetting might have been due to correctly remembering the answer previously given, but failing to realize that it had been wrong. These findings have implications for a variety of situations in which people are queried about past memory performance.     

Being a good witness: The roles of benevolence and working memory capacity in rapport’s effect on eyewitness memory

Prior studies suggest that building rapport with eyewitnesses can produce measurable recall improvements, but the underlying mechanisms of rapport’s possible effects on recall remain underexplored. The present study investigated two possible mechanisms for rapport’s impact: (1) improved working memory capacity and (2) increased benevolence. Participants (N = 105) viewed a mock theft video, followed by one of two possible pre-interview interactions: rapport-building or a control interaction. Next, participants completed measures of working memory, altruism, and benevolence (pre-interview and post-interview), before recalling details of the theft. Analyses revealed that, when controlling for the effects of the interaction duration and participants’ pre- and post-interview benevolence, rapport did not affect eyewitness recall directly. However, rapport building did increase benevolence measured after and associated with the substantive eyewitness interview, which in turn predicted more accurate and new details reported, and fewer subjective/other details reported. These findings support benevolence toward the interviewer as a mechanism behind rapport’s effect on eyewitness recall. Implications for investigative interviews in relation to benevolence and motivating reciprocation are discussed.     

Effects of stress induced by a simulated shooting on recall by police and citizen witnesses

Two experiments address the accuracy of citizen and police witnesses in recalling stressful events. Participants saw 2 training scenarios. Experiment 1 evaluated the effects of active engagement and the presence of a simulated shooting on police officers' memory for details. Police officers recalled significantly fewer details from the scenario in which a shooting occurred. Active engagement did not influence recall. Experiment 2 compared the memory performance of police and citizen witnesses. Manipulation checks were added to assess the arousal produced by a shooting, and control procedures were added to evaluate the memorability of specific scenarios. Police and citizen witnesses did not differ reliably in accuracy. The perpetrator was remembered less well than the weapon when a simulated shooting occurred, and one scenario was significantly more difficult to remember than the other. The need to replicate eyewitness research with a variety of materials is discussed.     

Perceptions of Credibility for a Memory Report of a Single Versus Repeated Event

Summary: When a person experiences an event that has multiple similar instances (i.e., a repeated event), memories for details that change across instances are challenging to recall. We expected that third parties would perceive memory reports of instances of repeated events as less credible than they would unique (i.e., single) events. Undergraduates participated in a single or repeated event, during which critical details were presented. Participants were asked to recall the session 2 days later, and memory reports were video recorded. New participants then viewed one video and evaluated the credibility of the speaker's memory report. Overall, repeated‐event reports were seen as less credible than were single‐event reports, despite the reports being equally accurate. Although credibility research in the context of repeated events has focused exclusively on child populations, a range of applications exists for adults (e.g., criminal and industrial eyewitnesses, and asylum seekers); we discussed our findings in these areas.Copyright © 2017 John Wiley & Sons, Ltd.     

Using Personal Landmark Events Improves Judgments about Time,but not Contents,in Autobiographical Memory

Landmark events are strong memories that function as reference points for other memories. We examined whether people's accuracy in recalling when an earlier target event occurred was related to whether they spontaneously used personal landmark events or not. Participants completed two questionnaires separated by 2‐31 days. In the first, they described a personal event including what happened, who was there, where it was, and when it occurred. In the second questionnaire, they recalled the personal event and specific details. They also described whether they had used landmark events to assist their recall. Overall, participants' memories for temporal and content information faded over time. Spontaneous use of landmark events was associated with an increase in participants’ recall of temporal information but not content information. Analysis of the landmark events revealed that almost two‐thirds were significant events, such as birthdays, parties, and travel‐related events. Applications of the findings are discussed. Copyright © 2013 John Wiley & Sons, Ltd.     

The Effects of Alcohol on Crime‐related Memories: A Field Study

This field study investigated to what extent memory of criminally relevant details is affected at (close to) zero (M_BAC = 0.00%), moderate (M_BAC = 0.06%), and high (M_BAC = 0.16%) levels of alcohol intoxication. Participants (N = 76) were approached in bars and were invited to watch a mock crime from a perpetrator perspective. We also measured their blood alcohol concentration levels. After 3–5 days, when participants were sober, they underwent a free and cued recall task about the mock crime. Compared with sober controls, both moderately and highly intoxicated individuals were less complete when recollecting crime details, recalling up to 33% fewer correct details. Overall, intoxicated participants were less accurate during the cued recall task (i.e. they produced more errors) relative to sober participants. These accuracy effects were dose‐dependent for cued recall of salient features. Implications for police interrogations of defendants are discussed. Copyright © 2011 John Wiley & Sons, Ltd.     

Positive emotions enhance recall of peripheral details

Emotional arousal and negative affect enhance recall of central aspects of an event. However, the role of discrete emotions in selective memory processing is understudied. Undergraduates were asked to recall and rate autobiographical memories of eight emotional events. Details of each memory were rated as central or peripheral to the event. Significance of the event, vividness, reliving and other aspects of remembering were also rated for each memory. Positive affect enhanced recall of peripheral details. Furthermore, the impairment of peripheral recall was greatest in memories of anger, not of fear. Reliving the experience at retrieval was negatively correlated with recall of peripheral details for some emotions (e.g., anger) but not others (e.g., fear), irrespective of similarities in affect and intensity. Within individuals, recall of peripheral details was correlated with less belief in the memory's accuracy and more likelihood to recall the memory from one's own eyes (i.e., a field perspective).     

Emotional discussions reduce memory recall

People often discuss events they have seen and these discussions can influence later recollections. We investigated the effects of factual, emotional, and free retelling discussion on memory recollections of individuals who have witnessed an event. Participants were shown a video, made an initial individual recall, participated in one of the three retelling conditions (emotional versus factual versus free) or a control condition, and then recalled the event individually again. Participants in the factual and free retelling conditions reported more items not previously recalled than participants in the control condition did, while the emotional condition did not show the same advantage. Participants in all three retelling conditions failed to report more previously recalled items as compared with the control condition. Finally, a memory conformity effect was observed for all three retelling conditions. These findings suggest that eyewitnesses’ discussions may influence the accuracy of subsequent memory reports, especially when these discussions are focused on emotional details and thoughts.     

POSITIVE EMOTIONS ENHANCE RECALL OF PERIPHERAL DETAILS

Emotional arousal and negative affect enhance recall of central aspects of an event. However, the role of discrete emotions in selective memory processing is understudied. Undergraduates were asked to recall and rate autobiographical memories of eight emotional events. Details of each memory were rated as central or peripheral to the event. Significance of the event, vividness, reliving and other aspects of remembering were also rated for each event. Positive affect enhanced recall of peripheral details. Furthermore, the impairment of peripheral recall was greatest in memories of anger, not of fear. Reliving the experience at retrieval was negatively correlated with recall of peripheral details for some emotions (e.g., anger) but not others (e.g., fear), irrespective of similarities in affect and intensity. Within individuals, recall of peripheral details was correlated with less belief in the memory's accuracy and more likelihood to recall the memory from one's own eyes (i.e., a field perspective).     

The Role of Ease of Retrieval and Attribution in Memory Judgments: Judging Your Memory as Worse Despite Recalling More Events

Participants who had to recall 12 childhood events (a difficult task) were more likely to infer that they could not remember large parts of their childhood than participants who had to recall 4 events (an easy task), although the former recalled three times as many events. This pattern of results suggests that memory judgments are based on the experienced ease or difficulty of recall. Accordingly, the negative impact of recalling 12 events was attenuated when participants were led to attribute the experienced difficulty to the task rather than to the poor quality of their memory. The findings emphasize the role of subjective experiences and attribution in metamemory judgments.     

It Took Me by Surprise: Examining the Retroactive Enhancement Effect for Memory of Naturally Unfolding Events

In two experiments, we examined how accurately participants remembered details from a naturalistic, first-person perspective film, which ended with the protagonist either encountering or not encountering an unexpected detail. Participants who watched the film with the unexpected detail at the end displayed superior accuracy for preceding event details compared to those who watched a film without such a detail. This retroactive enhancement effect generalized across both visual and auditory details, but it appeared contingent upon the unexpected detail being relevant to the event’s story. The effect occurred whether participants’ memory was tested immediately or after a two-day delay. The present findings can be seen as consistent with prior work on synaptic tagging and long-term potentiation, but the phenomenon of retroactive enhancement has not been demonstrated previously for naturally unfolding events. Implications of the findings are discussed in relation to eyewitness memory and intrusive memories in post-traumatic stress disorder.     

“You and your best friend Suzy put Slime in Ms. Smollett’s desk”: Producing false memories with self-relevant details

Rates of false memory reports vary markedly in the published literature. In an effort to explain these differences, the present study investigated the effects of including different types of details in a false narrative upon subsequent false memory formation. Participants were assigned to one of four conditions in which the inclusion of self-relevant and/or specific details in a false event (putting a toy in a teacher's desk) was manipulated. Participants engaged in a standard memory recovery procedure over three interviews, involving recall for three true and one false event Upon completion, 68.2% of participants in self-relevant groups were judged as having created memories or images about the false event, as compared with 36.4% in non-self-relevant groups. Subjective ratings of memory intensity were higher for self-relevant groups, and self-relevant participants were less likely to correctly guess the false event. These findings indicate that including self-relevant details in suggested childhood events increases the likelihood that such events will be accepted as false memories.     

Processing memories of anger-eliciting events: the effect of asking 'why' from a distance

Preliminary experimental evidence suggests that ruminating about anger-eliciting events exacerbates anger and associated affect. However, no research has investigated the effect of rumination on processing memories of these events. This study examined the impact of manipulating cognitive processing when recalling anger-eliciting events. Participants (N=60) outlined an anger-related experience and were randomly allocated to recall the event according to an experimental instruction that manipulated recall perspective and emotional focus (distanced-why, distanced-what, immersed-why or immersed-what). Participants completed measures of negative affect and implicit and explicit anger, and returned the following day to complete measures that indexed frequency of intrusive memories of the event and memory-related distress. Contrary to prediction, participants allocated to the distanced-why condition did not report reduced anger. However, participants instructed to think about 'why' they experienced the emotions they did during the event (compared with 'what' emotions they experienced) reported more intrusions 24h later, regardless of vantage perspective. These results accord with theoretical models that emphasise the negative impact of a ruminative 'why' focus on the processing of past events.