Technical article about recovered memories and false memories.
Topics covered:
- The ‘false memory' position
- Evidence for genuine ‘recovered memories'
- Why the debate?
- An emerging scientific and professional consensus
- References
Clinicians working with survivors of traumatic experiences have frequently noted the existence of memory loss with no obvious physical cause and the recovery of additional memories during clinical sessions, although little systematic research has been conducted until recently. Indeed, amnesia is described in diagnostic manuals as a feature of post-traumatic stress disorder, although its presence is not necessary for this diagnosis. In the majority of these cases, people forget details of the traumatic event or events, or forget how they reacted at the time, although they remember that the event happened. They typically report that they have endeavoured not to think about the event, but have never forgotten that it occurred. In the critical cases currently being debated, memories of traumatic events appear to be recovered after a long period of time in which there was complete forgetting that they had ever happened. Although some of Britain's leading psychologists and psychiatrists described this kind of memory loss when treating soldiers in the last two world wars, the controversy has largely erupted in the context of recovered memories of child sexual abuse. It has been suggested that many, if not all, of these apparent recovered memories are the product of inappropriate therapeutic suggestion. This argument has been promulgated in particular by the False Memory Syndrome Foundation in the United States, by its counterpart, the British False Memory Society, and by their scientific advisors.
The ‘false memory' position
Loftus (1) suggested that at least some of the memories of child sexual abuse recovered in therapy after apparent total amnesia may not be veridical, but may be false memories encouraged or ‘implanted' by therapists who have prematurely decided that the patient is an abuse victim and who use inappropriate therapeutic techniques to persuade him or her to recover corresponding ‘memories'. The false memory societies have claimed that there are many cases known to them in which previously happy families have been disrupted by accusations of abuse that were only triggered when an adult child entered therapy. Particular scepticism has been levelled at reports of repeated abuse, all of which has apparently been forgotten, and it has been claimed that such reports are contradicted by what is known scientifically about memory. Reports of ‘repressed' memories of childhood abuse are generally regarded as clinical speculations and the psychoanalytical concept of repression as one that has no credible scientific support. Several reviewers claim that there is no empirical support for repression or dissociative amnesia in trauma victims. (2,3 and 4)
Loftus (1) and Lindsay and Read (5,6) have marshalled evidence to suggest that the creation of false memories within therapy is a possibility that must be taken seriously. For example, they review experimental studies conducted with non-clinical subjects concerning the fallibility and malleability of memory, and note the potential for inaccurate recall involved in techniques such as hypnosis. Experiments have demonstrated that people are sometimes confused about whether a recent event in the laboratory actually happened, or whether they only imagined it happening. Other experiments have repeatedly succeeded in implanting apparent childhood memories of single non-abusive events in approximately 25 to 30 per cent of subjects, particularly in those who score highly on measures of hypnotizability or suggestibility. These studies have tended to use repeated suggestion, sometimes backed up by ‘corroboration' from a family member—one kind of event used in these studies involved being lost in a shopping mall as a child.
Critics have argued that these experiments are a long way from being evidence that therapists could implant false memories of child abuse, and even the experimental studies have shown that successful suggestion depends on the plausibility of the event subjects are asked to believe in. Nevertheless, although no one has performed experiments in an attempt to implant the notion that abuse occurred, it is reasonable to argue that some patients may be highly suggestible and inclined to go along with the beliefs of therapists who may be their only source of support. If their therapist was convinced that abuse had occurred, put overt or covert pressure on their patient to ‘remember' this abuse, and was insufficiently alert to the unreliability of memory, there would be a greatly increased risk of false memories occurring.
In conclusion, the recently developed ‘false memory' position goes beyond previous concerns of a general nature about errors in memory, and specifically identifies a process whereby errors arise after a person has been subjected to repeated suggestive influences that the explanation for their symptoms lies in forgotten child sexual abuse. These influences are usually thought to occur in therapy, although it has been proposed that exposure to certain books or broadcast media may have the same effect. This position relies partly on information from the false memory societies about their members, and partly on experimental evidence from non-traumatic procedures in the laboratory. There has been little independent scrutiny of the data from members of false memory societies, and many of their claims, for example that parents have been falsely accused, that accusations only follow entry into therapy, or that there is a ‘false memory syndrome', are anecdotal and have not been empirically verified. (7)
Evidence for genuine ‘recovered memories'
Over 20 longitudinal and retrospective studies have now found that a substantial proportion of people reporting child sexual abuse (somewhere between 20 and 60 per cent) report periods in their lives (often lasting for several years) when they could not remember that the abuse had taken place. (8,9) Although the rates vary between studies, broadly similar findings have been obtained by clinical psychologists, psychiatrists, and cognitive psychologists in both clinical and community samples. As has been pointed out by critics of these studies, this evidence supports the forgetting of trauma, but does not yet have much to say about the mechanism (for example ‘repression') by which it occurs. Thus it would be true to say that while there is evidence for forgetting, there is little evidence for ‘repression' as such.
Three main factors support the argument that these apparently forgotten memories are not necessarily false.
- Surveys have also found recovered memories of other traumatic experiences such as witnessing accidents, experiencing medical procedures, physical abuse in childhood, and combat or war exposure including events connected to the Holocaust. (10) It is unclear how these could have been brought about by suggestion.
- A number of studies have found that apparent recovered memories occur prior to any therapy, and in the absence of any obvious prolonged suggestive influence.(11,12) Again, it is unclear how these could have been brought about by suggestion.
- Surveys of psychologists,(12) therapists,(10) and patients reporting childhood trauma(13) found that approximately 40 per cent of those with apparent recovered memories reported corroborative evidence for the content of the memories, such as abusers' confessions, testimony from other victims, and court records. Although the quality of this corroboration has been criticized, it seems unlikely that all these cases can be summarily dismissed. There are also substantial numbers of case studies reporting more detailed corroborative evidence for apparent recovered memories, some of this evidence of reasonably high quality. (14,15 and 16)
The quality of the research evidence supporting genuine recovered memories is mixed, and almost all the studies can be argued to have some flaws, but taken together the evidence for genuine memories of major traumatic events is far more extensive than the evidence for false memories of such events. Moreover, these observations need not, as has sometimes been claimed, contradict what we know about memory. Cognitive psychology recognizes that ordinary memory relies as much for its efficiency on the ability to inhibit unwanted material as on the ability to gain rapid access to relevant material. Experimental studies clearly demonstrate the inhibition of memory retrieval and the existence of a subgroup of individuals with poor memories for negative experiences. (17)
But even if forgetting of single traumas occurs, it is far from clear how repeated traumas could be completely forgotten. A hypothesis put forward by trauma researchers is that children learn to ‘dissociate' during the abuse, that is to say they are in an altered mental state in which they are less aware of the abuse and of any associated fear and pain. In this state they may, for example, report feeling numb, feeling as though they are observing events from outside their own body, or feeling that they have escaped into an alternative private world. This altered state may make the abuse easier to forget.
This hypothesis has received indirect support from the accounts of adults and children with known traumatic experiences, and from neurobiological research on the effects of extreme stress on memory. Whereas high levels of arousal often make events more difficult to forget, it has been argued by several well-known neuroscientists that extraordinarily high levels of catecholamines or other neuropeptides at the time of the trauma, perhaps in combination with a failure to release sufficient cortisol, may produce amnesia.(18,19) Several studies have demonstrated that the hippocampus, an area of the brain involved in memory, is smaller in traumatized subjects. (20) Changes in hippocampal volume have also been found in stressed animals, and these potentially reversible anatomical effects may have important implications for memory functioning under stress. Again, much of the evidence is indirect and not yet compelling. The intimate neuroanatomical connections between brain circuits involved in emotion and those involved in memory do, however, provide a good reason for believing that memory may not behave in the same way under conditions of extreme real-world stress as it does in ordinary laboratory experiments.
Why the debate?
From a purely scientific point of view, it should be evident that the quality of the available evidence is insufficient to justify any extreme position at present. However, scientific considerations have been secondary to the passionate advocacy practised by parents who claim to be falsely accused, and by accusers who claim that their memories of abuse are being ignored. Psychiatrists and psychologists have become caught up in the debate and in some cases have abandoned any pretence at neutrality. In the face of these overwhelming and desperately painful personal concerns, the quality of much of the argument has become debased. Thus, supposedly scientific contributions on both sides of this debate have questioned the motives and integrity of people with whom they disagree and have attempted to disparage opponents' professional abilities. Some of these same authors have made exclusive claims for the scientific legitimacy of their own perspective, subjecting opposing data to fierce scrutiny while being relatively uncritical of studies that support their point of view. Much of the literature is obfuscatory and confusing. Logical errors abound, seen for example in the conclusion that because a memory has been recovered in therapy, the practitioner must have been using ‘recovered memory therapy'.
A good example of the debate in action is the article by Pope et al. (4) on the evidence for dissociative amnesia in trauma victims and the commentary that follows it. (21) These articles demonstrate how widely differing conclusions can be drawn from the same set of studies, depending on the way terms are defined, on assumptions about what evidence should be given the most weight, and on the rigour with which alternative explanations are evaluated.
An emerging scientific and professional consensus
What should be clear by now is that extreme views, claiming that either false memories or genuine recovered memories are rare or impossible, cannot be supported by the available data. Nevertheless, the dispute continues about whether traumatic events, and particularly repeated traumas, can be forgotten and then remembered with essential accuracy. In my view it is safe to conclude from the evidence reviewed that the hypothesized implantation of false memories by practitioners cannot account for more than a subset of recovered memories (and at present it is entirely unclear how large or small this subset might be). False memories may certainly arise in other circumstances, but as yet there is little pertinent evidence. On the other hand, there is a great deal of plausible evidence supporting the existence of genuine recovered memories.
Although members of the advisory boards of false memory societies mostly remain sceptical, on the basis of the kind of evidence reviewed above many commentators now appear to accept that traumatic events can be forgotten and then remembered. For example, cognitive psychologists Lindsay and Read (6) concluded: ‘In our reading, scientific evidence has clear implications...memories recovered via suggestive memory work by people who initially denied any such history should be viewed with scepticism, but there are few grounds to doubt spontaneously recovered memories of common forms of child sexual abuse or recovered memories of details of never-forgotten abuse. Between these extremes lies a grey area within which the implications of existing scientific evidence are less clear and experts are likely to disagree'. Similarly, the consensus view among independent commentators, repeated in the 1995 report of the British Psychological Society's Working Party on Recovered Memories and the 1995 interim statement of the American Psychological Association's Working Group on Investigation of Memories of Childhood Abuse, is that memories may be recovered from total amnesia and they may sometimes be essentially accurate. Equally, such ‘memories' may sometimes be inaccurate in whole or in part.
In practical terms, the debate has had two major effects. First, proponents of ‘recovered memory therapy' are now almost impossible to find within the ranks of leading psychiatrists and psychologists. Despite the small amount of empirical support, there is widespread agreement that situations in which there is sustained suggestive influence, such as therapy, do have the potential to induce false memories. Active attempts to recover suspected forgotten memories may sometimes be appropriate in unusual or extreme cases, but both the client and the therapist must be aware of the risk of false memories. Techniques such as hypnosis and guided imagery should not be used without safeguards against potential suggestive influence. Second, good practice now requires both the therapist and the client to adopt a critical attitude towards any apparent memory that is recovered after a period of amnesia, whether or not this is within a therapeutic context, and not to assume that it necessarily corresponds to a true event. Even highly vivid traumatic memories (sometimes known as ‘flashbacks') may be misleading or inaccurate in some cases. Clinical guidelines are now available to help the practitioner avoid the twin perils of uncritically accepting false memories as true or summarily dismissing genuine recovered memories.(9,22)
References
1. Loftus, E.F. (1993). The reality of repressed memories. American Psychologist, 48, 518–37.
2. Brandon, S., Boakes, J., Glaser, D., and Green, R. (1998). Recovered memories of childhood sexual abuse. British Journal of Psychiatry, 172, 296–307.
3. Pope, H.G. and Hudson, J.I. (1995). Can memories of childhood abuse be repressed? Psychological Medicine, 25, 121–6.
4. Pope, H.G., Hudson, J.I., Bodkin, J.A., and Oliva, P. (1997). Can trauma victims develop ‘dissociative amnesia'? The evidence of prospective studies. British Journal of Psychiatry, 172, 210–15.
5. Lindsay, D.S. and Read, J.D. (1994). Psychotherapy and memories of childhood sexual abuse. Applied Cognitive Psychology, 8, 281–338.
6. Lindsay, D.S. and Read, J.D. (1995). ‘Memory work' and recovered memories of childhood sexual abuse: scientific evidence and public, professional and personal issues. Psychology, Public Policy and the Law, 1, 846–908.
7. Pope, K.S. (1996). Memory, abuse and science: questioning claims about the False Memory Syndrome epidemic. American Psychologist, 51, 957–74.
8. Freyd, J.J. (1996). Betrayal trauma: the logic of forgetting childhood abuse. Harvard University Press, Cambridge, MA.
9. Mollon, P. (1998). Remembering trauma: a psychotherapist's guide to memory and illusion. Wiley, Chichester.
10. Andrews, B., Brewin, C.R., Ochera, J., et al. The characteristics, context, and consequences of memory recovery among adults in therapy. British Journal of Psychiatry, in press.
11. Andrews, B., Morton, J., Bekerian, D., Brewin, C.R., Davies, G.M., and Mollon, P. (1995). The recovery of memories in clinical practice. Psychologist, 8, 209–14.
12. Feldman-Summers, S. and Pope, K.S. (1994). The experience of ‘forgetting' childhood abuse: a national survey of psychologists. Journal of Consulting and Clinical Psychology, 62, 636–9.
13. Herman, J.L. and Harvey, M.R. (1997). Adult memories of childhood trauma: a naturalistic clinical study. Journal of Traumatic Stress, 10, 557–71.
14. Cheit, R. (1998). The recovered memory project. Internet posting http://www.brown.edu/Departments/Taubman_Center/Recovmem/Archive.html .
15. Schooler, J.W. (1994). Seeking the core: the issues and evidence surrounding recovered accounts of sexual trauma. Consciousness and Cognition, 3, 452–69.
16. Schooler, J.W., Bendiksen, M., and Ambadar, Z. (1997). Taking the middle line: can we accommodate both fabricated and recovered memories of sexual abuse? In Recovered memories and false memories (ed. M.A. Conway), pp. 251–92. Oxford University Press.
17. Brewin, C.R. and Andrews, B. (1998). Recovered memories of trauma: phenomenology and cognitive mechanisms. Clinical Psychology Review, 18, 949–70.
18. Bremner, J.D., Krystal, J.H., Charney, D.S., and Southwick, S.M. (1996). Neural mechanisms in dissociative amnesia for childhood abuse: relevance to the current controversy surrounding the ‘false memory syndrome'. American Journal of Psychiatry, 153 (Supplement), 71–82.
19. Yehuda, R. and Harvey, P. (1997). Relevance of neuroendocrine alterations in PTSD to memory-related impairments of trauma survivors. In Recollections of trauma: scientific evidence and clinical practice (ed. J.D. Read and D.S. Lindsay), pp. 221–42. Plenum Press, New York.
20. Stein, M.B., Koverola, C., Hanna, C., Torchia, M.G., and McClarty, B. (1997). Hippocampal volume in women victimized by childhood sexual abuse. Psychological Medicine, 27, 951–9.
21. Brewin, C.R. (1998). Commentary: questionable validity of ‘dissociative amnesia' in trauma victims. British Journal of Psychiatry, 172, 216–17.
22. Pope, K.S. and Brown, L.S. (1996). Recovered memories of abuse: assessment, therapy, forensics. American Psychological Association, Washington, DC.