Misinformation revisited: New evidence on the suggestibility of memory

In three experiments involving a total of 623 subjects, a series of slides was shown depicting a student in a college bookstore stealing a variety of items. Next, subjects read a narrative describing the event that contained some misinformation and some neutral information about several critical details. Finally, subjects took a memory test. On this test, subjects were asked to list exemplars of 20 specified categories but were instructed not to list any items that they saw in the slide sequence. Analogous to Lindsay's (1990) adaptation of Jacoby, Woloshyn, and Kelley's (1989) “logic-ofopposition” paradigm, the tendency to report suggested details was thus set in opposition to the ability to remember the source of those details. Therefore, we interpreted failure to include suggested details as exemplars as evidence that subjects believed those details had been present in the event. Analysis of subjects' responses under opposition instructions suggests that some misled subjects come to genuinely believe that they saw items that, in reality, were only suggested to them.     

The Effect of Different Types of Leading Questions on Adult Eyewitnesses with Mild Intellectual Disabilities

Adults with an intellectual disability (ID) are often considered poor witnesses; however, this may depend on the type of questions asked during investigative interviews. We examined the impact of four different types of misleading questions commonly used in interviews. These questions varied in their specificity, presumptive knowledge and structure (open or closed). Forty‐one adults with a mild ID watched a short film; they were then interviewed about what had happened. Half of the questions contained misleading information. In a later recognition test, participants showed a misinformation effect: they correctly recognised more items about which they had received control information than the items about which they had received misleading information. Closer inspection of the data revealed that both closed and open presumptive questions generated the largest misinformation effects. These findings highlight the vulnerability of adults with an ID to misleading questions, specifically those that presume certain information to be true. Copyright © 2013 John Wiley & Sons, Ltd.     

Acceptance of misleading information by children and adults.

A total of 294 subjects from Grades 1, 3, 6, and college viewed a videotape of a birthday party and heard misleading information embedded in three of nine questions they answered about what they had seen. Two days later, the subjects answered six additional questions which tested whether they had accepted the misleading information. Half the subjects had heard misleading information about three of the questions and half heard misleading information about the other three questions. The results indicated that a significant number of both children and adults accepted the misleading information embedded in three of the six questions. For only one question was there any difference in the likelihood that subjects in different grades would accept misleading information.     

Misled subjects may know more than their performance implies

Many studies have demonstrated that subjects exposed to misleading postevent information are likely to report the misinformation with confidence on subsequent tests of memory for the event. The purpose of the present studies was to determine whether subjects exposed to misleading postevent information come to believe they remember seeing the misinformation at the original event. A second question addressed by the present studies is whether exposure to misinformation reduces subjects' ability to remember the source of items they witnessed at the original event. In two experiments, subjects viewed a slide sequence depicting an event, were subsequently exposed to misleading information or neutral information about selected aspects of the event, and were later tested on their memory for the source of original and misleading details. The results showed that exposure to misinformation did not lead subjects to believe they remembered seeing the misinformation, nor did it reduce subjects' ability to accurately identify the source of originally seen details. The same pattern of results was obtained whether subjects were tested immediately (Experiment 1) or after a 1-day delay (Experiment 2). Collectively, the results suggest that subjects may report misinformation even if they know they do not remember seeing it.     

Correcting the misinformation effect

Decades of memory research have demonstrated a dire need for effective methods of correcting misinformation, particularly once it has been encoded. However, much of this research has exposed participants to misinformation first then provided a correction, and used indirect memory questions. Using a misinformation effect (ME) paradigm, in which participants' memory is distorted by misleading postevent information, we examine whether corrections can combat memory distortion on direct memory tests. Experiment 1 showed corrections greatly reduced the ME. Experiment 2 replicated this finding with a longer lag time (3 min) between exposure to misinformation and its correction, except for participants that read only the misinformation and its correction. Experiment 3 ruled out the possibility that participants reported the most recent information they read, suggesting participants evaluate the correction's veracity. Finally, a meta‐analysis of the three experiments reiterates that corrections may be effective in combating misinformation.     

Habitual acceptance of misinformation: Examination of individual differences and source attributions

This study identifies individuals who are habitually susceptible to accepting postevent misinformation across testing on three separate events. The results indicate that those individuals identified as habitually susceptible exhibited higher dissociation scores and less of an association between memory accuracy and confidence than did the individuals identified as nonhabitually susceptible. When they were asked to identify the source of the remembered information, similar patterns of source attributions were found for all individuals when they were responding correctly and incorrectly to nonmisinformation and when they were correctly rejecting items of misinformation. Importantly, from a source-monitoring perspective, individuals identified as habitually susceptible demonstrated a different pattern of source attributions than did those classified as nonhabitually susceptible when they were accepting misinformation. Habitually susceptible individuals were as likely to attribute the source of their memory incorrectly to something seen in the experienced event as to attribute it correctly to something read after the fact.     

Why misinformation is more likely to be recognised over time: A source monitoring account

Although memory for actual events tends to be forgotten over time, memory for misinformation tends to be retrieved at a stable rate over long delays or at a rate greater than that found immediately after encoding. To examine whether source monitoring errors contribute to this phenomenon, two experiments investigated subjects' memory for the source of misinformation at different retention intervals. Subjects viewed a slide presentation, read a narrative containing misinformation, and, either 10 minutes or 1 week later, completed a recognition test about details seen in the slides and about the source of these details. After the longer retention interval in both experiments, participants were more likely to agree that they had seen misleading information and were also more likely to incorrectly associate the misinformation with the slide event. Theoretical implications of these findings are considered.     

No Benefit of Eye-Closure Rehearsal in a Unimodal Recognition Memory Test for Word Items

Recent studies have suggested that closing the eyes helps memory retrieval in recall tests for audiovisual clips that contain multimodal information. In two experiments, we examined whether eye-closure improves recognition memory performance for word lists presented unimodally (i.e., visually or aurally). In the encoding phase, participants saw or heard a list of unrelated, meaningful word items. After a fixed retention interval of 1 week (Experiment 1, n = 110) and 5 min (Experiment 2, n = 44), the participants were asked to mentally rehearse the items with their eyes open or closed, and then they performed a recognition test. The results revealed no effect of eye-closure rehearsal on recognition performance. We discuss the possible reasons why no eye-closure benefit was found in recognition memory tests for unrelated word items.     

False memories and source‐monitoring problems: criterion differences

A source‐monitoring/memory suggestion experiment was used to produce false memories and a signal‐detection analysis was conducted to determine if criterion differences could help explain their production. The procedure and stimuli were adapted from Zaragoza and Lane ( 1994 ). Participants saw slides depicting a crime and then answered questions about the slides with some of the questions containing suggested or misleading information. After a brief delay filled with several assessment tests, a list of items was presented and the participants were asked to identify whether each item came from the slides, the questions, both or neither. The results showed that all participants produced false memories but those who adopted more lenient criteria produced more false memories. In addition, those with stricter criteria scored lower on an assessment of dissociative experiences. These results were interpreted within a source‐monitoring framework. Copyright © 2002 John Wiley & Sons, Ltd.     

Misleading postevent information: Testing parameterized models of integration in memory

A classic series of experiments by Loftus, Miller and Burns (1978) showed that a person's recollection of an event can be changed by misleading postevent information. Several hypotheses accounting for this effect have been proposed. Loftus' hypothesis of destructive updating claims that the original memory is destroyed by the postevent information. The coexistence hypothesis asserts that the older memory survives but is rendered inaccessible through a mechanism of inhibition or suppression. The non-conflict hypothesis simply accounts for the effect by claiming that subjects can only be misled if they did not encode or if they forgot the original event. These three hypotheses were modelled with the help of all-or-none probabilistic event trees. An experiment was conducted in order to test the three models and to assess parameter values. The experiment followed the classic Loftus paradigm. We suggested to some subjects that they had seen a stopsign, whereas in fact they had seen a traffic light. The misleading postevent information resulted in poorer reproduction of traffic light. Later, all subjects were asked whether they could remember the color of the traffic light, even if they believed they had seen a stopsign. The results showed that subjects who received the misleading post-event information were at least as good at recalling the color of the traffic light as subjects who did not receive misleading information. The no-conflict model accounts well for the obtained results, although the two other, less parsimonious, models cannot be entirely rejected.     

Developmental Patterns of Eyewitness Responses to Repeated and Increasingly Suggestive Questions

Kindergarten, Grade 2, Grade 4, and adult subjects viewed a brief video of two children arguing about the use of a bicycle. One week later subjects were asked for their free recall of the events in the video followed by sets of hierarchically arranged, increasingly suggestive questions that suggested a correct (positive-leading), an incorrect (misleading), or no specific (unbiased-leading) answer, with the final level of questioning for each item being a three-alternative multiple-choice question. Correct free recall varied with age, with the kindergarten and Grade 2 children generally following the lead of the first-level questions more so than the older subjects. Older children were as accurate as adults in responding to questions about the central items, but not so for noncentral items. Developmental differences were found in responses to repeated suggestive questioning, with kindergarten children following misleading questions and changing answers more often than older subjects. On the final, multiple-choice questions, kindergarten children were able to provide the correct answer as often as they had to the initial questions, despite intervening errors. Findings are discussed in terms of the type of questions presented, the repetition factors, and the opportunities for subjects changing their answers in response to subsequent questions about the same item.     

The impact of misleading questions on eyewitness memory in children and adults

The study examined developmental patterns of the negative effect of misleading post‐event information in two different kinds of eyewitness interviews. A total of 284 subjects aged between five and 64 years were shown a short video about a theft and three weeks as well as four weeks later questioned about it. The social pressure in the interview after three weeks was manipulated by asking half of the subjects suggestive and misleading questions. The other half was asked open‐ended and unbiased questions. In the neutral interview four weeks later, all subjects were asked the same set of recognition questions about the event. The results revealed that preschoolers in particular had problems with the interplay between cognitive and social factors (social pressure induced through the wording of the misleading questions) in the interview setting after three weeks. In the neutral recognition test, all age groups were shown to suffer from prior misinformation to about the same extent. However, with an exception in the group of 6‐year‐old children the negative effect of prior misinformation on the accuracy of recognition proved to be due to items that were peripheral to the observed event. Copyright © 2000 John Wiley & Sons, Ltd.     

Monitoring item and source information: Evidence for a negative generation effect in source memory

Item memory and source memory were assessed in a task that simulated a social conversation. Participants generated answers to questions or read statements presented by one of three sources (faces on a computer screen). Positive generation effects were observed for item memory. That is, participants remembered topics of conversation better if they were asked questions about the topics than if they simply read statements about topics. However, a negative generation effect occurred for source memory. That is, remembering the source of some information was disrupted if participants were required to answer questions pertaining to that information. These findings support the notion that item and source memory are mediated, as least in part, by different processes during encoding.     

The role of commitment in producing misinformation effects in eyewitness memory

We conducted three experiments exploring conditions in which misleading postevent information interferes with people’s ability to remember details about an event they witnessed. The key condition included in each experiment was the misled-plus-commit condition. After viewing slides depicting a crime, subjects in this condition read a narrative that contained misinformation. Following the narrative, they completed an interpolated recognition test that induced them to select the misinformation. Assessment of memory for the slides using a final, modified recognition test indicated that performance in the misled-plus-commit condition was most frequently near chance, whereas performance in the control condition was far above chance. This result was obtained on four separate occasions and indicates that prior retrieval of misinformation impairs memory. Another important finding was that the deleterious effect of passively reading about misinformation in a narrative is not as great as the effect of reading about it and then selecting it on an interpolated test. Actively retrieving misinformation seems to cause particularly deleterious effects. Our conclusion is that the findings are compatible with the retrieval blocking hypothesis, which assumes that repeated retrieval of misinformation blocks access to the witnessed information.     

Discrepancy detection and vulnerability to misleading postevent information

When people are exposed to misleading details after a witnessed event, they often claim that they saw the misleading details as part of the event. We refer to this as themisinformation effect. In four experiments, involving 570 subjects, we explored the role that discrepancy detection plays in the misinformation effect. Experiment 1 showed that subjects who naturally read a post-event narrative more slowly were more resistant to the effects of misleading information contained in the narrative. In Experiment 2, subjects who naturally read more slowly were more likely to detect a discrepancy between what they were reading and what was stored in their memory. In Experiment 3, subjects who were instructed to read slowly were more likely to detect a discrepancy than were those who were instructed to read quickly. In Experiment 4, subjects who were instructed to read slowly were more resistant to misleading postevent information. Taken together, these results suggest that longer reading times are associated with a greater scrutiny of postevent information. This leads to an increased likelihood that discrepancies will be detected and that the misinformation will be resisted.     

Similarity of encoding context does not influence resistance to memory impairment following misinformation

Several recent studies have shown that exposure to verbal misleading post-event information does not impair subjects' ability to retrieve originally seen details. Two experiments were conducted to test the hypothesis that subjects would be more susceptible to memory impairment if the original and misleading information were presented in similar contextual formats. The results showed that misleading information did not lead to memory impairment when both original and misleading information were presented in the context of slides (Experiment 1) or when both original and misleading information were presented in the context of narratives (Experiment 2). Furthermore, resistance to memory impairment was observed both at relatively low levels of memory for the original information (Experiment 1) and at relatively high levels of memory for the original information (Experiment 2). The implications of the present results for interference principles of forgetting are discussed.     

Memory strength affects reporting of misinformation

A model of long-term retention was used to examine whether and how the strength of original information (differences in learning and testing time) and the strength of misleading information (differences in timing and frequency) influence 3- to 5-year-olds' memory for an event. In three experiments, preschoolers viewed a slide presentation depicting an event, some of them were asked misleading questions, and memory for event details was tested. There was little evidence of memory impairment, but exposure to misleading information encouraged reporting of this information. Differences in learning influenced reporting in that children exposed to the event once reported more misled details than those who saw the event multiple times. Furthermore, preschoolers who saw the event once were just as susceptible to misleading information whether exposed to misinformation once or three times; however, preschoolers who had seen the event multiple times were susceptible only to repeated presentations of misinformation. Given that the reporting of misinformation is determined by the degree of integrity of both the original and misleading information, it is important to control for differences in trace strength for both types of information in future research.     

Neutral details associated with emotional events are encoded: evidence from a cued recall paradigm

Enhanced emotional memory often comes at the cost of memory for surrounding background information. Narrowed-encoding theories suggest that this is due to narrowed attention for emotional information at encoding, leading to impaired encoding of background information. Recent work has suggested that an encoding-based theory may be insufficient. Here, we examined whether cued recall—instead of previously used recognition memory tasks—would reveal evidence that non-emotional information associated with emotional information was effectively encoded. Participants encoded positive, negative, or neutral objects on neutral backgrounds. At retrieval, they were given either the item or the background as a memory cue and were asked to recall the associated scene element. Counter to narrowed-encoding theories, emotional items were more likely than neutral items to trigger recall of the associated background. This finding suggests that there is a memory trace of this contextual information and that emotional cues may facilitate retrieval of this information.