Individual differences in working memory capacity affect false memories for missing aspects of events

Recently, Gerrie, Belcher, and Garry (2006) found that, when participants watch an event with parts missing, they falsely claim to have seen the missing parts—but they were more likely to claim they had seen less crucial parts than more crucial parts. Their results fit with a source-monitoring framework (SMF; Johnson, Hashtroudi, & Lindsay, 1993) explanation of false memories. In this paper we used individual differences in working memory capacity (WMC) to examine the SMF explanation of false memories for missing aspects of events. An accumulating body of research suggests that WMC is strongly related to controlling attention, including the ability to distinguish between sources of information. The primary purpose of the present study was to examine whether people with larger WMC are better able to ward off false memories for missing information than those with a smaller WMC. We showed that higher WMC reduced false recognition of crucial information, but did not change false recognition of noncrucial information. Additionally, we found that WMC had little effect on participants’ subjective experience of true and false recognition of events, regardless whether the information was crucial or not. These results provide further evidence that people's WMC is related to their source-monitoring ability.     

Warnings reduce false memories for missing aspects of events

When people see movies with some parts missing, they falsely recognize many of the missing parts later. In two experiments, we examined the effect of warnings on people's false memories for these parts. In Experiment 1, warning subjects about false recognition before the movie (forewarnings) reduced false recognition, but warning them after the movie (postwarnings) reduced false recognition to a lesser extent. In Experiment 2, the effect of the warnings depended on the nature of the missing parts. Forewarnings were more effective than postwarnings in reducing false recognition of missing noncrucial parts, but forewarnings and postwarnings were similarly effective in reducing false recognition of crucial missing parts. We use the source monitoring framework to explain our results.     

False recognition occurs more frequently during source identification than during old-new recognition

A number of recent reports have investigated false memories using variants of the Deese-Roediger-McDermott (DRM) paradigm. Because these false memories have been difficult to eliminate, this study investigated whether false recognition could be reduced by incorporating source-monitoring criteria into decision processes. Making claims about the manner in which items were learned should require more careful scrutiny of memories, and therefore false recognition should be minimized with source instructions as compared with old-new recognition instructions. In 3 experiments that varied the combination of sources, false recognition was increased rather than reduced by applying source-monitoring processes. The theoretical implications of these counterintuitive results are discussed in terms of the old-new detection component of source judgments.     

Explorations in the social contagion of memory

Four experiments examined social influence on the development of false memories. We employed the social contagion paradigm: A subject and a confederate see scenes and then later take turns recalling items from the scenes, with the confederate erroneously reporting some items that were not present in the scenes; on a final test, the subject reports these suggested items when instructed to recall only items from the scenes. The first two experiments showed that the social contagion effect persisted when subjects were explicitly warned about the possibility that confederates' responses might induce false memories and when they were tested via source-monitoring tests that explicitly gave the choice of attributing suggested items to the other person. Levels of false recall and recognition increased with the number of times the misleading information was suggested (Experiment 3), and subjects were more likely to incorporate the erroneous responses of an actual confederate on a recognition/source test as compared with those of a simulated confederate (Experiment 4). Collectively, the data support the claim that false memories may be transmitted between people and reveal critical factors that modulate the social contagion of memories.     

Source misattributions may increase the accuracy of source judgments

Misattribution of remembered information from one source to another is commonly associated with false memories, but we demonstrate that it also may underlie memories that accord with past events. Participants imagined drawings of objects in four different locations. For each, a drawing of a similarly shaped object was seen in the same location, a different location, or not seen. When tested on memory for objects' origin (seen/imagined) and location, more false "seen" responses, but also more correct location responses, were given to imagined objects if a similar object had been seen, versus not seen, in the same location. We argue that misattribution of feature information (e.g., shape, location) from seen objects to similar imagined ones increased false memories of seeing objects but also increased correct location memories, provided the misattributed location matched the imagined objects' location. Thus, consistent with the source-monitoring framework, imperfect source-attribution processes underlie false and true memories.     

Importing perceived features into false memories

False memories sometimes contain specific details, such as location or colour, about events that never occurred. Based on the source-monitoring framework, we investigated one process by which false memories acquire details: the reactivation and misattribution of feature information from memories of similar perceived events. In Experiments 1A and 1B, when imagined objects were falsely remembered as seen, participants often reported that the objects had appeared in locations where visually or conceptually similar objects, respectively, had actually appeared. Experiment 2 indicated that colour and shape features of seen objects were misattributed to false memories of imagined objects. Experiment 3 showed that perceived details were misattributed to false memories of objects that had not been explicitly imagined. False memories that imported perceived features, compared to those that presumably did not, were subjectively more like memories for perceived events. Thus, perception may be even more pernicious than imagination in contributing to false memories.     

Importing perceived features into false memories

False memories sometimes contain specific details, such as location or colour, about events that never occurred. Based on the source-monitoring framework, we investigated one process by which false memories acquire details: the reactivation and misattribution of feature information from memories of similar perceived events. In Experiments 1A and 1B, when imagined objects were falsely remembered as seen, participants often reported that the objects had appeared in locations where visually or conceptually similar objects, respectively, had actually appeared. Experiment 2 indicated that colour and shape features of seen objects were misattributed to false memories of imagined objects. Experiment 3 showed that perceived details were misattributed to false memories of objects that had not been explicitly imagined. False memories that imported perceived features, compared to those that presumably did not, were subjectively more like memories for perceived events. Thus, perception may be even more pernicious than imagination in contributing to false memories.     

Source-monitoring training facilitates preschoolers' eyewitness memory performance

Preschool children are more susceptible to misleading postevent information than are older children and adults. One reason for young children's suggestibility is their failure to monitor the source of their memories, as in, for example, discriminating whether an event was seen live versus on television. The authors investigated whether source-monitoring training would decrease preschoolers' suggestibility. Thirty-six 3-4-year-olds observed target live and video events and were then given source-monitoring or recognition (control) training on nontarget events. Following training, all children answered 24 misleading and nonmisleading target-event questions. Children given source-monitoring training were more accurate than control group children in response to misleading and nonmisleading yes-no questions and in response to nonmisleading, open-ended questions. Implications for strategy development, dual representation, and child witness interviewing are discussed.     

Working memory predicts the rejection of false memories

The relationship between working memory capacity (WMC) and false memories in the memory conjunction paradigm was explored. Previous research using other paradigms has shown that individuals high in WMC are not as likely to experience false memories as low-WMC individuals, the explanation being that high-WMC individuals are better able to engage in source monitoring. In the memory conjunction paradigm participants are presented at study with parent words (e.g., eyeglasses, whiplash). At test, in addition to being presented with targets and foils, participants are presented with lures that are composed of previously studied features (e.g., eyelash). It was found that high-WMC individuals had lower levels of false recognition than low-WMC individuals. Furthermore, recall-to-reject responses were analysed (e.g., "I know I didn't see eyelash because I remember seeing eyeglasses") and it was found that high-WMC individuals were more likely to utilise this memory editing strategy, providing direct evidence that one reason that high-WMC individuals are not as prone to false memories is because they are better able to engage in source monitoring.     

Not strange but not true: self-reported interest in a topic increases false memory

People are more likely to recall both true and false information that is consistent with their pre-existing stereotypes, schemata and desires. In addition, experts in a particular field are more likely to experience false memory in relation to their area of expertise. Here, we investigate whether level of interest, as distinct from level of knowledge, and in the absence of self-professed expertise, is associated with increased false memory. 489 participants were asked to rank 7 topics from most to least interesting. They were then asked if they remembered the events described in four news items related to the topic they selected as the most interesting and four items related to the topic selected as least interesting. In each case, three of the events depicted had really happened and one was fictional. A high level of interest in a topic increased true memories for the topic and doubled the frequency of false memories, even after controlling for level of knowledge. We interpret the results in the context of the source-monitoring framework and suggest that false memories arise as a result of interference from existing information stored in domain-related schemata.     

Individual differences in susceptibility to false memory in the Deese-Roediger-McDermott paradigm

The authors addressed whether individual differences in the working memory capacity (WMC) of young adults influence susceptibility to false memories for nonpresented critical words in the Deese-Roediger-McDermott associative list paradigm. The results of 2 experiments indicated that individuals with greater WMC recalled fewer critical words than individuals with reduced WMC when participants were forewarned about the tendency of associative lists (e.g., bed, rest, . . .) to elicit illusory memories for critical words (e.g., sleep). In contrast, both high and low WMC participants used repeated study-test trials to reduce recall of critical words. These findings suggest that individual differences in WMC influence cognitive control and the ability to actively maintain task goals in the face of interfering information or habit.     

Working memory predicts the rejection of false memories

The relationship between working memory capacity (WMC) and false memories in the memory conjunction paradigm was explored. Previous research using other paradigms has shown that individuals high in WMC are not as likely to experience false memories as low-WMC individuals, the explanation being that high-WMC individuals are better able to engage in source monitoring. In the memory conjunction paradigm participants are presented at study with parent words (e.g., eyeglasses, whiplash). At test, in addition to being presented with targets and foils, participants are presented with lures that are composed of previously studied features (e.g., eyelash). It was found that high-WMC individuals had lower levels of false recognition than low-WMC individuals. Furthermore, recall-to-reject responses were analysed (e.g., “I know I didn't see eyelash because I remember seeing eyeglasses”) and it was found that high-WMC individuals were more likely to utilise this memory editing strategy, providing direct evidence that one reason that high-WMC individuals are not as prone to false memories is because they are better able to engage in source monitoring.     

Inventing stories: Forcing witnesses to fabricate entire fictitious events leads to freely reported false memories

Studies of the forced fabrication effect have shown that participant witnesses are prone to developing false memories for specific items or details that they have been forced to fabricate earlier (e.g., what type of hat someone wore). Building on these earlier findings, the present study assessed whether participants would develop false memories if forced to fabricate entire fictitious events that were more complex and extended in time and involved people, locations, and actions that they had never seen. Participants vehemently resisted fabricating these events, and false memory development over the short term (1-week recognition test) was limited. However, after 8 weeks, participants freely reported their forced fabrications nearly 50% of the time and did so even when they had correctly and publicly rejected them earlier on the 1-week recognition test. This is the first evidence that participant witnesses will freely incorporate into their eyewitness accounts entire fictitious events that they have earlier been forced to fabricate.     

False memories of fabricated political events

In the largest false memory study to date, 5,269 participants were asked about their memories for three true and one of five fabricated political events. Each fabricated event was accompanied by a photographic image purportedly depicting that event. Approximately half the participants falsely remembered that the false event happened, with 27% remembering that they saw the events happen on the news. Political orientation appeared to influence the formation of false memories, with conservatives more likely to falsely remember seeing Barack Obama shaking hands with the president of Iran, and liberals more likely to remember George W. Bush vacationing with a baseball celebrity during the Hurricane Katrina disaster. A follow-up study supported the explanation that events are more easily implanted in memory when they are congruent with a person's preexisting attitudes and evaluations, in part because attitude-congruent false events promote feelings of recognition and familiarity, which in turn interfere with source attributions.     

Evaluating characteristics of false memories: Remember/know judgments and memory characteristics questionnaire compared

Subjects hearing a list of associates to a nonpresented lure word later often claim to have heard the lure (Deese, 1959; Roediger & McDermott, 1995). To examine the characteristics of such false memories, subjects completed a memory characteristics questionnaire (MCQ; Johnson, Foley, Suengas, & Raye, 1988) or made remember/know (RK; Gardiner & Java, 1993) judgments for previously heard theme associates and nonpresented lures. MCQ ratings indicated that false memories for lures had less auditory detail and less remembered feelings and reactions than memories for presented words. In addition, rates of false recognition for lures were significantly lower than rates of correct recognition when items from various themes were intermixed instead of blocked at acquisition and subjects made MCQ ratings instead of RK judgments. This demonstrates that false memories can be affected both by how they are acquired and by how extensively they are examined at retrieval.     

Memory distortion in people reporting abduction by aliens

False memory creation was examined in people who reported having recovered memories of traumatic events that are unlikely to have occurred: abduction by space aliens. A variant of the Deese/Roediger-McDermott paradigm (J. Deese. 1959; H. L. Roediger III & K. B. McDermott, 1995) was used to examine false recall and false recognition in 3 groups: people reporting recovered memories of alien abduction. people who believe they were abducted by aliens but have no memories, and people who deny having been abducted by aliens. Those reporting recovered and repressed memories of alien abduction were more prone than control participants to exhibit false recall and recognition. The groups did not differ in correct recall or recognition. Hypnotic suggestibility, depressive symptoms, and schizotypic features were significant predictors of false recall and false recognition.     

Do Cognitive Interview Instructions Contribute to False Beliefs and Memories?

To examine whether exposing people to false events using instructions taken from the cognitive interview creates false beliefs and false memories, we conducted an experiment where participants took part in two sessions. First, they rated how confident they were that they had experienced certain childhood events and their memories of those events; they also rated how plausible they thought the events were. Second, 2 weeks later, participants were exposed to two of three false target events: one high, one moderate, and one low plausibility. For the first event, participants were instructed to either report everything or mentally reinstate the event context. For the second event, participants received both instructions. The third event was the control event about which participants received no instructions. Finally, participants rated their confidence and memories the second time. The results showed that the cognitive interview instructions had little to no effect on the development of false beliefs and false memories. Copyright © 2012 John Wiley & Sons, Ltd.     

Aging and the misinformation effect: a neuropsychological analysis

Older adults' susceptibility to misinformation in an eyewitness memory paradigm was examined in two experiments. Experiment 1 showed that older adults are more susceptible to interfering misinformation than are younger adults on two different tests (old-new recognition and source monitoring). Experiment 2 examined the extent to which processes associated with frontal lobe functioning underlie older adults' source-monitoring difficulties. Older adults with lower frontal-lobe-functioning scores on neuropsychological tests were particularly susceptible to false memories in the misinformation paradigm. The authors' results agree with data from other false memory paradigms that show greater false recollections in older adults, especially in those who scored poorly on frontal tests. The results support a source-monitoring account of aging and illusory recollection.     

Forgetting having denied: The “amnesic” consequences of denial

The concept of denial has its roots in psychoanalysis. Denial has been assumed to be effective in blocking unwanted memories. In two experiments, we report that denial has unique consequences for remembering. In our two experiments, participants viewed a video of a theft, and half of the participants had to deny seeing certain details in the video, whereas the other half had to tell the truth. One day later, all participants were given either a source-monitoring recognition or a recall task. In these tasks, they were instructed to indicate (1) whether they could remember talking about certain details and (2) whether they could recollect seeing those details in the video. In both experiments, we found that denial made participants forget that they had talked about these details, while leaving memory for the video itself unaffected. This denial-induced forgetting was evident for both the source-monitoring recognition and recall tests. Furthermore, when we asked participants after the experiment whether they could still not remember talking about these details, those who had to deny were most likely to report that they had forgotten talking about the details. In contrast to a widely held belief, we show that denial does not impair memory for the experienced stimuli, but that it has a unique ability to undermine memory for what has been talked about.     

Filling in the Gaps: False Memories and Partisan Bias

While cognitive psychologists have learned a great deal about people's propensity for constructing and acting on false memories, the connection between false memories and politics remains understudied. If partisan bias guides the adoption of beliefs and colors one's interpretation of new events and information, so too might it prove powerful enough to fabricate memories of political circumstances. Across two studies, we first distinguish false memories from false beliefs and expressive responses; false political memories appear to be genuine and subject to partisan bias. We also examine the political and psychological correlates of false memories. Nearly a third of respondents reported remembering a fabricated or factually altered political event, with many going so far as to convey the circumstances under which they “heard about” the event. False-memory recall is correlated with the strength of partisan attachments, interest in politics, and participation, as well as narcissism, conspiratorial thinking, and cognitive ability.