Applied Cognitive Psychology, Appl. Cognit. Psychol. (2016) Published online in Wiley Online Library (wileyonlinelibrary.com) DOI: 10.1002/acp.3220 Creating Memories for False Autobiographical Events in Childhood: A Systematic Review CHRIS R. BREWIN1* and BERNICE ANDREWS2 1University College London, London, UK 2Royal Holloway, University of London, London, UK Summary: Using a framework that distinguishes autobiographical belief, recollective experience, and confidence in memory, we review three major paradigms used to suggest false childhood events to adults: imagination inflation, false feedback and memory implantation. Imagination inflation and false feedback studies increase the belief that a suggested event occurred by a small amount such that events are still thought unlikely to have happened. In memory implantation studies, some recollective experience for the suggested events is induced on average in 47% of participants, but only in 15% are these experiences likely to be rated as full memories. We conclude that susceptibility to false memories of childhood events appears more limited than has been suggested. The data emphasise the complex judgements involved in distinguishing real from imaginary recollections and caution against accepting investigator-based ratings as necessarily corresponding to participants’ self-reports. Recommendations are made for presenting the results of these studies in courtroom settings.Copyright © 2016 John Wiley & Sons, Ltd. The early 1990s saw a well-documented concern that some imagine events that have not occurred; ‘false feedback’ psychotherapy patients might be wrongly convinced by their studies, in which participants are given mainly generic false therapists that they had experienced sexual abuse in child- information suggesting they were likely to have experienced hood and recover corresponding memories of events that an event and memory implantation studies in which the had not occurred (Lindsay & Read, 1994; Loftus, 1993). suggested occurrence of the false event is supported by false The possibility was raised that a variety of suggestive thera- testimony from an individual’s family members or individu- peutic techniques could create illusory memories of abuse ally doctored photographs. Although the latter two paradigms having happened. Subsequently, experiments were designed overlap somewhat, we treat them separately here because that showed false memories of childhood events could be they typically differ both in the procedures used and the out- created under laboratory conditions. Although the success come data (changes in self-ratings versus investigator-based of these experiments has been widely accepted, summarising ratings). The majority of studies using all three of these their results accurately is complex because different paradigms imply the practical relevance of their work by paradigms and memory measures have been employed, and including mention of memory for child abuse or trauma, ther- the findings have been very variable. This may explain apy or legal proceedings. why to date there have been no systematic reviews of the Some initial reactions to the publication of these studies research on creating false childhood memories in adults de- were to conclude that imagining events that had not spite undoubted professional and public interest in the topic, happened can ‘change memory’ (Garry & Polaschek, 2000) as illustrated by a recent special issue of Applied Cognitive or that it was easy to implant false childhood memories Psychology titled ‘Reshaping memories through conversa- (Wade, Garry, Read, & Lindsay, 2002). More recently, tions: Considering the influence of others on historical articles have suggested that, on average, false childhood mem- memories of abuse’. The two aims of this review are to de- ories can be implanted in almost 40% of participants (Strange, velop a framework for describing the nature of these Wade, & Hayne, 2008). A State of the Science Editorial (Laney laboratory-produced memories and to use this framework to & Loftus, 2013) concluded that ‘all these techniques produced document more precisely what these studies have and have false memories in substantial numbers of research participants’ not shown. The review should be of benefit to researchers, and went on to describe further research that has been ‘key to experts testifying in legal settings and psychotherapists establishing the reliability of laboratory-induced false memory, attempting to evaluate the status of childhood memories in as well as their relevance to the precipitating issue of recovered a therapeutic context. memories of child sexual abuse’ (p. 139). Other authors Three experimental paradigms have been most commonly (Conway, 2013) have concluded that ‘wholly false memories employed to mimic possible therapy-inspired distortions to are more common than previously thought, especially for child- childhood autobiographical memory (Laney & Loftus, hood events and, even more alarmingly, it turns out to be 2013; Schacter & Loftus, 2013). In order of the amount of almost trivially easy to create false memories in others’ (p. 567). explicit suggestion and apparent corroboration provided to The findings of this research have also been widely participants, these are the following: imagination inflation accepted within psychology textbooks, with statements (D. studies, in which participants are instructed to repeatedly A. Bernstein, 2014) such as: ‘Merely thinking about certain objects or events or hearing sounds or seeing photos associ- ated with them appears to make false memories of them *Correspondence to: Chris R. Brewin, Clinical, Educational & Health more likely’ (p. 223); or (Nolen-Hoeksema, Fredrickson, Psychology, University College London, Gower Street, London WC1E ‘ fi 6BT, UK. Loftus, & Lutz, 2014) memories of entirely ctional events E-mail: [email protected] have been shown to be implantable under controlled Copyright © 2016 John Wiley & Sons, Ltd. C. R. Brewin and B. Andrews conditions…it is possible to induce such memories by imaginary rather than real. Research on source memory has merely having people imagine fictional renderings of their considered in detail the problems of establishing the truth pasts’ (pp. 289–290). In the absence of a systematic review, of one’s own recollective experiences and emphasised the however, it is unclear whether these statements accurately complexity of the evaluative processes involved (Johnson, capture the available data. 2006). Johnson suggested that a variety of factors are in- One reason for caution is that a number of researchers in volved, including the amount of perceptual and contextual the field have observed how studies vary considerably in their detail available, the plausibility of what is recalled, the exis- definition and operationalisation of false memory (Scoboria, tence of supporting knowledge and beliefs, information Mazzoni, Kirsch, & Relyea, 2004; Smeets, Merckelbach, about mental operations such as imagination that might pro- Horselenberg, & Jelicic, 2005). Moreover, discriminating vide an alternative explanation and the decision criteria whether one’s memories are true or false is a complex process adopted. Based on existing findings, she proposed that false involving high-level evaluative procedures (Johnson, 1997; memories are more likely when procedures are used that in- Lindsay & Johnson, 2000). Perhaps as a consequence, the crease the similarity between true and imagined events, such results of studies using all three paradigms have been highly as those that increase the amount of imagery available, that variable. These observations suggest the value of applying an decrease the accessibility of disconfirming information and explicit framework to the existing data in order to evaluate the that lead to features of real events being imported. literature. In this article, we describe such a framework Given these complexities in discriminating whether expe- grounded in the previous work of autobiographical memory riences correspond to true or false events, it has been neces- researchers and apply it to the results of the three major sary to stipulate criteria by which researchers can conclude methods of suggesting false childhood memories. that individuals have fully recollected a particular episode from their past. A prominent view from autobiographical memory research (Brewer, 1986) is that three elements are A FRAMEWORK FOR DISCRIMINATING TRUTH needed: the belief that the episode was personally experi- AND FALSITY IN ONE’S OWN enced by the self, the presence of (usually visual) imagery AUTOBIOGRAPHICAL MEMORIES and the confidence that this imagery is a veridical record of the originally experienced episode. Similar criteria have been The term ‘autobiographical memory’ refers to the totality of employed by other leading researchers. Pezdek and col- what can be recalled about the self and includes knowledge leagues suggested that recollective experiences are only of both facts and events. In thinking about event memory, likely to be accepted if the events are initially judged as plau- a useful starting point is the ‘remember-know’ distinction sible and consistent with script-relevant knowledge (Pezdek, (Mandler, 1980; Tulving, 1985) that has been so influential Finger, & Hodge, 1997). Hyman additionally proposed that in experimental studies of episodic memory retrieval: Partic- the creation of false memories involves the acceptance of ipants can experience their past knowledge of a stimulus the false event as plausible, the