Personalized and not general suggestion produces false autobiographical memories and suggestion-consistent behavior

Suggesting false childhood events produces false autobiographical beliefs, memories and suggestion-consistent behavior. The mechanisms by which suggestion affects behavior are not understood, and whether false beliefs and memories are necessary for suggestions to impact behavior remains unexplored. We examined the relative effects of providing a personalized suggestion (suggesting that an event occurred to the person in the past), and/or a general suggestion (suggesting that an event happened to others in the past). Participants (N=122) received a personalized suggestion, a general suggestion, both or neither, about childhood illness due to spoiled peach yogurt. The personalized suggestion resulted in false beliefs, false memories, and suggestion-consistent behavioral intentions immediately after the suggestion. One week or one month later participants completed a taste test that involved eating varieties of crackers and yogurts. The personalized suggestion led to reduced consumption of only peach yogurt, and those who reported a false memory showed the most eating suppression. This effect on behavior was equally strong after one week and one month, showing a long lived influence of the personalized suggestion. The general suggestion showed no effects. Suggestions that convey personal information about a past event produce false autobiographical memories, which in turn impact behavior.     

Lasting false beliefs and their behavioral consequences

False beliefs and memories can affect people's attitudes, at least in the short term. But can they produce real changes in behavior? This study explored whether falsely suggesting to subjects that they had experienced a food-related event in their childhood would lead to a change in their behavior shortly after the suggestion and up to 4 months later. We falsely suggested to 180 subjects that, as children, they had gotten ill after eating egg salad. Results showed that, after this manipulation, a significant minority of subjects came to believe they had experienced this childhood event even though they had initially denied having experienced it. This newfound autobiographical belief was accompanied by the intent to avoid egg salad, and also by significantly reduced consumption of egg-salad sandwiches, both immediately and 4 months after the false suggestion. The false suggestion of a childhood event can lead to persistent false beliefs that have lasting behavioral consequences.     

The consequences of suggesting false childhood food events

We combined data across eight published experiments (N = 1369) to examine the formation and consequences of false autobiographical beliefs and memories. Our path models revealed that the formation of false autobiographical belief fully mediated the pathway between suggesting to people that they had experienced a positive or negative food-related event in the past and current preference for that food. Suggestion indirectly affected intention to eat the food via change in autobiographical belief. The development of belief with and without memory produced similar changes in food preferences and behavior intention, indicating that belief in the event drives changes in suggestion-related attitudes. Finally, positive suggestions (e.g., “you loved asparagus the first time you tried it”) yielded stronger effects than negative suggestions (e.g., “you got sick eating egg salad”). These findings show that false autobiographical suggestions lead to the development of autobiographical beliefs, which in turn, have consequences for one's attitudes and behaviors.     

Creating false memories for events that occurred before versus after the offset of childhood amnesia

We examined whether false images and memories for childhood events are more likely when the event supposedly took place during the period of childhood amnesia. Over three interviews, participants recalled six events: five true and one false. Some participants were told that the false event happened when they were 2 years old (Age 2 group), while others were told that it happened when they were 10 years old (Age 10 group). We compared participants’ reports of the false event to their reports of a true event from the same age. Consistent with prior research on childhood amnesia, participants in the Age 10 group were more likely than participants in the Age 2 group to remember their true event and they reported more information about it. Participants in the Age 2 group, on the other hand, were more likely to develop false images and memories than participants in the Age 10 group. Furthermore, once a false image or memory developed, there were no age-related differences in the amount of information participants reported about the false event. We conclude that childhood amnesia increases our susceptibility to false suggestion, thus our results have implications for court cases where early memories are at issue.     

Creating false memories for events that occurred before versus after the offset of childhood amnesia

We examined whether false images and memories for childhood events are more likely when the event supposedly took place during the period of childhood amnesia. Over three interviews, participants recalled six events: five true and one false. Some participants were told that the false event happened when they were 2 years old (Age 2 group), while others were told that it happened when they were 10 years old (Age 10 group). We compared participants' reports of the false event to their reports of a true event from the same age. Consistent with prior research on childhood amnesia, participants in the Age 10 group were more likely than participants in the Age 2 group to remember their true event and they reported more information about it. Participants in the Age 2 group, on the other hand, were more likely to develop false images and memories than participants in the Age 10 group. Furthermore, once a false image or memory developed, there were no age-related differences in the amount of information participants reported about the false event. We conclude that childhood amnesia increases our susceptibility to false suggestion, thus our results have implications for court cases where early memories are at issue.     

“Queasy does it”: False alcohol beliefs and memories may lead to diminished alcohol preferences

Studies have shown that false memories can be implanted via innocuous suggestions, and that these memories can play a role in shaping people's subsequent attitudes and preferences. The current study explored whether participants (N = 147) who received a false suggestion that they had become ill drinking a particular type of alcohol would increase their confidence that the event had occurred, and whether their new-found belief would subsequently affect their alcohol preferences. Results indicated that participants who received a suggestion that they had gotten sick drinking rum or vodka before the age of 16 reported increased confidence that the suggested experience had occurred. Moreover, participants who received a false alcohol suggestion also showed a strong trend to report diminished preference for the specified type of alcohol after the false suggestion. Implantation of a false memory related to one's past drinking experiences may influence current drink preferences and could be an important avenue for further exploration in the development of alcohol interventions.     

Hypnotic pseudomemories,prehypnotic warnings,and the malleability of suggested memories

This study used Orne's nocturnal events paradigm to test the effects of warning highly hypnotizable participants about the possibility of hypnotic false memories. We found that warnings reduced suggestibility but not false memories during hypnosis. Fewer warned participants (12/32, 38 per cent) than unwarned participants (12/16, 75 per cent) accepted the suggestion to hear a noise that awakened them when they were age-regressed to a night of the previous week. However, an analysis of only those persons who accepted the suggestion during hypnosis showed that the warning had no effect on their posthypnotic pseudomemories: among this group, 75 per cent of warned versus 58 per cent of unwarned persons stated immediately after hypnosis that the noise occurred in reality (i.e., reported a pseudomemory). During a final confidential assessment, 58 per cent of the warned participants who had accepted the noise suggestion reported a pseudomemory, versus 50 per cent of the unwarned participants. Comparing pseudomemory rates across all participants, regardless of whether they passed or failed the noise suggestion, 28 per cent of warned participants versus 44 per cent of unwarned participants reported pseudomemories, a nonsignificant difference. Finally, warned and unwarned participants were equally confident in their false memories. © 1998 John Wiley & Sons, Ltd.     

Fluctuating confidence: the dynamic consequences of true/false affirmatives and denials on how a listener appraises their personal past

The present study examined the mnemonic consequences of true/false denials and affirmatives on how a listener appraises their personal past. To this end, participants (listeners) rated the extent to which they were confident certain events occurred during their childhood. They rated these events both before and after a confederate (speaker) denied or affirmed the occurrence of four different childhood events each, for a total of eight “rehearsed” events. For each set (denials and affirmatives) of events, half were true and half were false. In turn, this created four types of events (two each): true denials, true affirmatives, false denials, and false affirmatives. Additionally, half of the participants were told that the speaker was provided independent information about the veracity of the event’s occurrence (“expert” condition). Overall, listeners were less confident in the occurrence of false denial events, but more so when they believed the speaker to be more knowledgeable of the listeners memories, more confident in false affirmative events and, counter intuitively, more confident in the occurrence of true denial events. These results underscore the importance of a nuanced approach to the mnemonic consequences of true and false denials and affirmations in the course of social interactions.     

Response: Most people who think that they are likely to enter psychotherapy also think it is plausible that they could have forgotten their own memories of childhood sexual abuse

Pezdek and Blandon‐Gitlin ( 2008 ) found that 25% of their participants reported as plausible or very plausible that they themselves could have been a victim of childhood sexual abuse without being able to remember it. In addition, they found that the 25% figure increased to 61% for participants who reported that they were likely at some point in their life to seek psychotherapy. Given past work showing that it is easier to implant a false memory for plausible events, and counter to Pezdek and Blandon‐Gitlin's conclusions, these data point to a substantial danger of implanting false memories of childhood sexual abuse during therapy in many people and in most people who are likely to go into therapy. Theoretical issues regarding plausibility are discussed. Copyright © 2008 John Wiley & Sons, Ltd.     

Susceptibility to memory distortion: how do we decide it has occurred?

When given suggestive information, some people can be led to believe that they had experiences that they did not actually have. For example, they may come to believe falsely that they got sick eating particular foods as children, and as a result of that belief they may avoid the foods. But how do we know that someone has developed a false belief or memory in this research? The criteria we choose when classifying whether someone has fallen for the suggestion are somewhat arbitrary. We reanalyze our prior data, using different criteria for deciding that a person fell for the suggestion (called a "believer") or did not (called a "non-believer"). Changing criteria obviously affects the percentage of people who are called susceptible and could conceivably affect the conclusions reached about that group. Comparisons between false memories and true memories could differ, too, depending on how memories are defined.     

Fabrication inflation increases as source monitoring ability decreases

The current research looked at the effects of lying about a false childhood event on the liar's memory for the event. Participants attempted to convince researchers that false events had actually happened to them. In Experiment 1, participants showed a Fabrication Inflation Effect in that they were more likely to increase their beliefs in the lied-about events than control events. Individual differences such as scores on the Dissociative Experience Scale, frequency of lying, and self-reported feelings of discomfort while lying were related to rates of fabrication inflation. In Experiment 2, participants also showed fabrication inflation and were more likely to inflate their likelihood ratings when the lie was created during a separate session from the posttest. Results from both studies support the idea that Source Monitoring failures may cause participants to increase their likelihood ratings of lied-about events. These results suggest that intentional lying may lead some participants to increase their beliefs in their own fabrications. Applications to the legal field are discussed.     

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.     

The pull of the past: when do habits persist despite conflict with motives?

To identify the factors that disrupt and maintain habit performance, two field experiments tested the conditions under which people eat out of habit, leading them to resist motivational influences. Habitual popcorn eaters at a cinema were minimally influenced by their hunger or how much they liked the food, and they ate equal amounts of stale and fresh popcorn. Yet, mechanisms of automaticity influenced habit performance: Participants ate out of habit, regardless of freshness, only when currently in the context associated with past performance (i.e., a cinema; Study 1) and only when eating in a way that allowed them to automatically execute the response cued by that context (i.e., eating with their dominant hand; Study 2). Across all conditions, participants with weaker cinema-popcorn-eating habits ate because of motivations such as liking for the popcorn. The findings reveal how habits resist conflicting motives and provide insight into promising mechanisms of habit change.     

The Red Herring technique: a methodological response to the problem of demand characteristics

In past research, we planted false memories for food related childhood events using a simple false feedback procedure. Some critics have worried that our findings may be due to demand characteristics. In the present studies, we developed a novel procedure designed to reduce the influence of demand characteristics by providing an alternate magnet for subjects' natural suspicions. We used two separate levels of deception. In addition to giving subjects a typical untrue rationale for the study (i.e., normal deceptive cover story), we built in strong indicators (the "Red Herring") that the study actually had another purpose. Later, we told subjects that we had deceived them, and asked what they believed the "real purpose" of the study was. We also interviewed a subset of subjects in depth in order to analyze their subjective experiences of the procedure and any relevant demand. Our Red Herring successfully tricked subjects, and left little worry that our false memory results were due to demand. This "double cross" technique may have widespread uses in psychological research that hopes to conceal its real hypotheses from experimental subjects.     

False reports of childhood events in appropriate interviews

The present study employed the "parental misinformation" paradigm to examine whether individuals report false events from their childhood even when they are interviewed in an appropriate manner by a trained interviewer. Each participant was interviewed on three occasions. By the final interview, one participant produced a "full" report, and six participants produced "partial" reports, of childhood events that did not occur. Although participants reported perceiving greater pressure to report the false events than the real events, independent judges' ratings of social pressure in the interviews did not differ as a function of what type of event participants were being asked about. Participants also reported higher confidence in their parents', compared to their own, recall of events from their childhood. False reports were also positively correlated with scores on both the full and the revised versions of the Dissociative Experiences Scale, and negatively correlated with score on the Self-Monitoring scale. These results indicate that, despite being interviewed in an appropriate manner by a trained interviewer, some participants will falsely report events from their childhoods.     

Emotional content of true and false memories

Many people believe that emotional memories (including those that arise in therapy) are particularly likely to represent true events because of their emotional content. But is emotional content a reliable indicator of memory accuracy? The current research assessed the emotional content of participants’ pre-existing (true) and manipulated (false) memories for childhood events. False memories for one of three emotional childhood events were planted using a suggestive manipulation and then compared, along several subjective dimensions, with other participants’ true memories. On most emotional dimensions (e.g., how emotional was this event for you?), true and false memories were indistinguishable. On a few measures (e.g., intensity of feelings at the time of the event), true memories were more emotional than false memories in the aggregate, yet true and false memories were equally likely to be rated as uniformly emotional. These results suggest that even substantial emotional content may not reliably indicate memory accuracy.     

Developmental reversals in false memory: a review of data and theory

Can susceptibility to false memory and suggestion increase dramatically with age? The authors review the theoretical and empirical literatures on this counterintuitive possibility. Until recently, the well-documented pattern was that susceptibility to memory distortion had been found to decline between early childhood and young adulthood. That pattern is the centerpiece of much expert testimony in legal cases involving child witnesses and victims. During the past 5 years, however, several experiments have been published that test fuzzy-trace theory's prediction that some of the most powerful forms of false memory in adults will be greatly attenuated in children. Those experiments show that in some common domains of experience, in which false memories are rooted in meaning connections among events, age increases in false memory are the rule and are sometimes accompanied by net declines in the accuracy of memory. As these experiments are strongly theory-driven, they have established that developmental improvements in the formation of meaning connections are necessary and sufficient to produce age increases in false memory.     

Interviewing Witnesses: Forced Confabulation and Confirmatory Feedback Increase False Memories

In two experiments, adults who witnessed a videotaped event subsequently engaged in face-to-face interviews during which they were forced to confabulate information about the events they had seen. The interviewer selectively reinforced some of the participants' confabulated responses by providing confirmatory feedback (e.g., "Yes, _is the correct answer") and provided neutral (uninformative) feedback for the remaining confabulated responses (e.g., "O.K. _"). One week later, participants developed false memories for the events they had earlier confabulated knowingly. However, confirmatory feedback increased false memory for forcibly confabulated events, increased confidence in those false memories, and increased the likelihood that participants would freely report the confabulated events 1 to 2 months later. The results illustrate the powerful role of social-motivational factors in promoting the development of false memories.     

The role of perceptual elaboration and individual differences in the creation of false memories for suggested events

Witnesses who are exposed to false or misleading information in the course of an investigation are often asked follow‐up questions designed to elicit more detailed information about the alleged objects/events. The results of the present study showed that pressing witnesses to elaborate on the perceptual characteristics of suggested events increased false memory for these events. Specifically, participants who were asked about the perceptual details of suggested events (e.g. their location, physical appearance, etc.) were much more likely to later claim they ‘definitely’ remembered witnessing the fictions events than participants who were exposed to the same suggestions but were not probed about additional perceptual details. In addition, the present study examined the role of individual difference variables in susceptibility to suggestion. The results showed that scores on the Tellegen Absorption Scale (but not the Dissociative Experiences Scale and the Creative Imagination Scale) were correlated with susceptibility to false memory in this paradigm. Copyright © 2001 John Wiley & Sons, Ltd.     

情绪对饮食行为的影响

人类的饮食行为受到诸多因素的影响, 包括生理因素、心理因素及社会文化因素等, 其中情绪对饮食行为的影响日益受到研究者的重视, 这种影响一般表现为摄入量的多少和食物(热量)的选择。通过探讨不同情绪下临床和非临床个体食物摄入量的表现, 总结发现消极情绪导致个体暴饮暴食的可能更大。积极情绪影响下的饮食行为的研究结果则存在分歧: 生理角度解释为积极情绪能够促进个体的享乐机制, 导致进食行为增加; 而自我控制理论则认为积极情绪增加了个人资源以抵制美食诱惑。此外, 进一步探讨了情绪影响下饮食行为的神经生理机制。未来在饮食相关的临床研究和治疗上, 需要对情绪影响下的饮食行为有更深入的神经机制方面的探究。