Now you see it; now you don't: inhibiting recall and recognition of scenes

Postevent misleading information can distort people's memories by altering and adding scenes. But can you also inhibit the retrieval of information from memory? In two studies we show that postevent information can make memory for a scene less accessible. In both studies participants first saw an event (e.g. a restaurant scene displayed in slides, or a drunk‐driving incident shown via a video clip). Later they were shown the same event without a critical scene and were told either to use this to generate a story (Experiment 1) or to imagine the event (Experiment 2). Finally they were tested. Relative to controls, this postevent omission led to fewer people reporting the critical scene in free recall and in recognition. Thus, we demonstrated that it may be possible to inhibit memories. This finding has important implications for eyewitness testimony and the recovered memory debate. Copyright © 2001 John Wiley & Sons, Ltd.     

Solving the eyewitness problem

Faulty eyewitness testimony is a major source of wrongful convictions. Four solutions are examined to safeguard against mistaken testimony having undue impact: (1) to overturn any conviction based solely on the uncorroborated testimony of a single eyewitness, (2) to require that an attorney be present at any pretrial identification procedure, (3) to allow an expert to testify during the trial about factors of perception and memory that could affect a witness's accuracy, and (4) to have the judge deliver a cautionary instruction to the jury, admonishing them to carefully scrutinize eyewitness testimony, or to educate them about such testimony. Each alternative is discussed within the context of psychological research and legal cases.     

Expert testimony and jury decision making: An empirical analysis

This experiment examines the influence of expert psychological testimony on juror decision making in eyewitness identification cases. Experienced jurors and undergraduate mock jurors viewed versions of a videotaped trial, rated the credibility of the eyewitness and the strength of the prosecution's and defense's cases, and rendered verdicts. In the absence of expert testimony jurors were insensitive to eyewitness evidence. Expert testimony improved juror sensitivity to eyewitness evidence without making them more skeptical about the accuracy of the eyewitness identification. Few differences emerged between the experienced jurors and undergraduate mock jurors.     

Speech style and occupational status affect assessments of eyewitness testimony

This study examined how speech style and occupational status affect mock jurors' assessments of eyewitness testimony. Mock jurors (n = 120) watched a video of a man testifying about witnessing an attempted robbery. The eyewitness exhibited either a powerless or powerful speech style and reported either a high or low (or no) status occupation during his testimony. Results indicated that high occupation status and powerful speech style led to more favorable evaluations of the eyewitness's testimony and of the case against the defendant than powerless speech style and low/no occupation status. Implications of these results on considerations of eyewitness testimony and future research are discussed.     

Self-relevance enhances susceptibility to false memory

Eyewitness testimony serves as important evidence in the legal system. Eyewitnesses of a crime can be either the victims themselves—for whom the experience is highly self-referential—or can be bystanders who witness and thus encode the crime in relation to others. There is a gap in past research investigating whether processing information in relation to oneself versus others would later impact people's suggestibility to misleading information. In two experiments (Ns = 68 and 122) with Dutch and Chinese samples, we assessed whether self-reference of a crime event (i.e., victim vs. bystander) affected their susceptibility to false memory creation. Using a misinformation procedure, we photoshopped half of the participants' photographs into a crime slideshow so that they saw themselves as victims of a nonviolent crime, while others watched the slideshow as mock bystander witnesses. In both experiments, participants displayed a self-enhanced suggestibility effect: Participants who viewed themselves as victims created more false memories after receiving misinformation than those who witnessed the same crime as bystanders. These findings suggest that self-reference might constitute a hitherto new risk factor in the formation of false memories when evaluating eyewitness memory reports.     

The Influence of Eyewitness Nonidentifications on Mock-Jurors' Judgments of a Court Case1

Two experiments examined the effect of an eyewitness nonidentificution on mock-jurors' verdicts in robbery cases, as well as the effects of number of identifying eyewitnesses and status of the identifying witness (victim or bystander). Subjects read court case summaries that included variable eyewitness evidence and constant alibi, circumstantial, and character evidence. In Experiment 1, frequency of guilty verdicts was significantly less when an eyewitness testified in court that the defendant was not the perpetrator, even when this nonidentification opposed two positive identifications. In Experiment 2, a low guilty rate was again associated with the presence of a nonidentifier, but only when the nonidentifier actually testified in court and stipulated that the defendant is “not the man.” On the average, 70% of the jurors delivered guilty verdicts when both the victim and bystander gave identifying testimony, whereas 12.5% delivered guilty verdicts when the bystander gave opposing nonidentifying testimony. Guilty rates were unaffected by the identifying eyewitness' status and (in Experiment 2, but not Experiment 1) were higher when there were two (vs. one) identifying eyewitnesses.     

Children's expectations and episodic reports over 12 weeks: Influences on memory for a specially designed pediatric examination

This investigation extended work on the linkage between knowledge and remembering by exploring the relation between generic and episodic memory representations. Thirty 6-year-old children experienced a mock physical examination with some expected components omitted and other unexpected actions included. Immediately and again after 12 weeks, the children reported the event, answered questions about what usually happens in an examination, and rated their confidence in aspects of their reports. They remembered more typical than atypical present components, that is, those included in the examination, and, over time, falsely reported more typical than atypical actions. The children produced intrusions of expected-but-omitted medical features at the delay but with lower confidence ratings than they provided for correctly recalled items. Performance on a source monitoring task was associated with aspects of the children's confidence ratings for intrusions. The findings provide evidence that the relation between episodic and generic representations is dynamic and suggest that the capacity to differentiate between them contributes to the development of accurate eyewitness memory.     

Trivial persuasion in the courtroom: the power of (a few) minor details

Investigated the influence of trivial testimonial detail on judgments of 424 undergraduates who served as mock jurors. Ss read a summary of a court case involving robbery and murder. In Experiment 1, detailed testimony influenced judgments of guilt, even when the detail was unrelated to the culprit. In Experiment 2, detailed testimony was especially powerful when an opposing witness testified that she could not remember the trivial details. Subsequent analyses suggest that the impact of detailed testimony on guilt judgments is mediated by inferences about the eyewitnesses. When eyewitnesses provided more detail, they were generally judged to be more credible, to have a better memory for the culprit's face and for details, and to have paid more attention to the culprit.     

The effect of question type on resistance to misinformation about present and absent details

The typical misinformation effect shows that accuracy is lower for details about which people received misleading compared to non-misleading (control) information. In two experiments, we examined the misinformation effect for non-witnessed details (i.e., absent). Three question types introduced control, misleading, and absent details (closed, closed-detailed, and open questions) about a mock burglary video. On this misinformation test, participants' reports of absent details were less accurate than control details only when they were introduced using open questions. Misinformation effects in a subsequent recognition test were present for misleading details in both experiments, but for absent details only in Experiment 2. Experiment 2 also revealed that participants who avoided answering open questions containing misleading and absent details had more accurate memories for these details on the subsequent recognition test than participants who answered these questions. In both experiments, confidence was lowest for absent details. Implications for theory and practice are discussed.     

Effects of discrete emotions on young children's suggestibility

Two experiments investigated the effects of sadness, anger, and happiness on 4- to 6-year-old children's memory and suggestibility concerning story events. In Experiment 1, children were presented with 3 interactive stories on a video monitor. The stories included protagonists who wanted to give the child a prize. After each story, the child completed a task to try to win the prize. The outcome of the child's effort was manipulated in order to elicit sadness, anger, or happiness. Children's emotions did not affect story recall, but children were more vulnerable to misleading questions about the stories when sad than when angry or happy. In Experiment 2, a story was presented and emotions were elicited using an autobiographical recall task. Children responded to misleading questions and then recalled the story for a different interviewer. Again, children's emotions did not affect the amount of story information recalled correctly, but sad children incorporated more information from misleading questions during recall than did angry or happy children. Sad children's greater suggestibility is discussed in terms of the differing problem-solving strategies associated with discrete emotions.     

Repetition, not number of sources, increases both susceptibility to misinformation and confidence in the accuracy of eyewitnesses

Are claims more credible when made by multiple sources, or is it the repetition of claims that matters? Some research suggests that claims have more credibility when independent sources make them. Yet, other research suggests that simply repeating information makes it more accessible and encourages reliance on automatic processes—factors known to change people's judgments. In Experiment 1, people took part in a “misinformation” study: people first watched a video of a crime and later read eyewitness reports attributed to one or three different eyewitnesses who made misleading claims in either one report or repeated the same misleading claims across all three reports. In Experiment 2, people who had not seen any videos read those same reports and indicated how confident they were that each claim happened in the original event. People were more misled by—and more confident about—claims that were repeated, regardless of how many eyewitnesses made them. We hypothesize that people interpreted the familiarity of repeated claims as markers of accuracy. These findings fit with research showing that repeating information makes it seem more true, and highlight the power of a single repeated voice.     

Mood effects on eyewitness memory: Affective influences on susceptibility to misinformation

Does mood influence the accuracy of eyewitness recollections, and people’s susceptibility to misleading information in particular? Based on recent affect-cognition theories and research on eyewitness memory, three experiments predicted and found that positive affect promoted, and negative affect inhibited the incorporation of misleading information into eyewitness memories. This effect was obtained for both positive and negative events (Experiment 1), and for recorded as well as real-life incidents (Experiment 2). Participants had no meta-cognitive awareness of these mood effects, and affect-control instructions were ineffective in preventing them (Experiment 3). The cognitive mechanisms responsible for mood effects on eyewitness memories are discussed, and the implications of these findings for everyday memories, forensic practice and for current affect/cognition theorizing are considered.     

Hands up! A study of witnesses' emotional reactions and memories associated with bank robberies

This article presents some empirical findings concerning memory for violent real-life events. Witnesses who had observed a bank robbery, either as a victim or a bystander, were interviewed and studied with respect to emotional reactions and memory for detailed information about the robbery. The consistency of the witnesses' accounts was measured by a comparison of information gathered in the police reports and the recollection given in a research interview. Overall, the results showed relatively high accuracy rates after an extended time interval with respect to specific details about the robbery (e. g. action, weapon, clothing). For some details, however, the witnesses showed a rather low performance (e. g. colour of eyes and hair, and details of the surrounding circumstances). There was no significant relationship between rated degree of emotion and the number of details remembered. These findings contradict the negative relationship between stress and memory that many experts on eyewitness testimony believe in (Kassin, Ellsworth, and Smith, 1989). Points of commonality in findings from real-life studies and simulation studies are discussed.     

The effect of post‐identification feedback on the recall of crime and perpetrator details

The present study examines the effect of identification feedback on the quantity and accuracy of crime event details recalled, willingness to attempt misleading questions and confidence in the accuracy of these details. All participants (N = 60) viewed a short video clip of a staged building society robbery and then made a false identification of the robber from a target‐absent photospread. Eyewitnesses were next given confirming feedback (i.e. told that they had identified the suspect), disconfirming feedback (i.e. told that they had failed to identify the suspect) or no feedback. All eyewitnesses then attempted a series of short‐answer questions relating to details about the robber, accomplice, victim, building society, theft and getaway. Disconfirming feedback significantly reduced eyewitness confidence in recall accuracy but there was no significant effect of feedback on the overall quantity and accuracy of details recalled or willingness to attempt misleading questions. The theoretical implications of these results are discussed. Copyright © 2005 John Wiley & Sons, Ltd.