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REFLECTIONS ON 'RECOVERED MEMORIES'

This paper, slightly modified here, first appeared in volume 10 of the 'Skeptical Intelligencer' (the Journal of ASKE, the Association for Skeptical Enquiry), 2007, pp 2-11.

This issue of the Skeptical Intelligencer contains two articles that have appeared in the Newsletter of the British False Memory Society (BFMS). The first (September 2006 issue) is a review of the recovered/false memory controversy by Daniel Wright, James Ost and Chris French and the second (September 2007 issue) is a discussion by James Ost and Kimberly Wade of a research paper that investigated the neural correlates of memory suppression. The latter paper is not only of academic interest: it illustrates how research findings can be interpreted sensationally and uncritically by the mass media.

The BFMS has very kindly sent me complimentary copies of its Newsletter since January 1994 (Volume 2, Number 1) and they are available for inspection by any ASKE member (and most are now available for inspection on the BFMS website. I am grateful to Madeline Greenhalgh, the Director of the BFMS, and to the authors themselves for allowing me to reproduce the two articles.

This paper is largely an account of my professional experience of 'recovered memories' and related phenomena. Much is anecdotal and does not aspire to the rigorous scholarly and scientific standards of a formal paper. I have not always provided references and anyone wanting these is welcome to contact me.

The British False Memory Society

I first became aware of the BFMS in 1993 when I read about it in the papers. There was already an American society, and others were forming across the world. Members were mainly parents whose adult children had accused them of sexually abusing them in childhood. These allegations were made after the accusers had been undergoing psychotherapy or counselling, during the course of which traumatic memories of events in their childhood, of which they had no awareness prior to the therapy, were 'recalled', usually with the aid of procedures such as hypnosis or merely through leading questions and suggestions by the therapist.

As a rule these people had sought help for the usual problems for which people seek psychological therapy - depression, eating disorders, phobias, anxiety states and so on - and not because they had any thoughts or feelings of having been sexually violated by anyone, least of all their parents. Most often they would be women and the alleged perpetrators would be their fathers, sometimes with the collusion of their mothers. Uncles and friends of the family would also be collectively involved in some cases. The 'memories' elicited were usually of quite extensive physical and sexual abuse. Often they were not merely vague ideas or feelings: they were very vivid and realistic (sometimes with dreams and 'flashbacks' and the clients had no doubt in their minds that the events really happened.

Put very simply, the theoretical rationale for this kind of therapy is that the experiences of abuse were so traumatic that the person cannot handle the associated memories and they are 'repressed' - denied access to consciousness by defence mechanisms of which the individual is not conscious (i.e. it is not simply a deliberate strategy of trying not to think about the events). However, the distressing memories are still present in the unconscious and continue to have an adverse effect on the individual's psychological wellbeing - hence his or her problems and symptoms and inability to make sense of them. Therapy allows the defences to be relaxed and the memories are allowed conscious representation and hence the opportunity to be 'processed' and resolved within the therapeutic context and beyond.

Returning to the contemporary recovered-memory controversy, once the memories of abuse were 'recovered', with the encouragement of their therapists, the clients would often telephone or write to their parents, informing them that they had now recalled what had happened and indicating that they would have no further contact with them, at least not until they themselves decided. This would be considered part of the therapeutic process: the victim (or 'survivor') of abuse is now empowered and in charge her life and able to confront her abuser as a mature, assertive adult.

All of this would come as a 'bolt from the blue' for the parents and other family members, especially those who had maintained a close and loving relationship with the person concerned. Typically, there would be not one shred of evidence that any abuse had occurred and sometimes the supposed events could not, in any case, have happened because they were contradicted by known historical facts; or they were so extensive and bizarre, involving for example neighbours, other children including siblings, and animals, as well as Satanic worship - as to defy any possibility of their going undetected at the time and remaining so for years afterwards. Yet the accused parents had no opportunity to defend themselves; indeed some were prosecuted in the criminal courts purely on the evidence of the therapy.

No excuse can be offered that the therapists concerned were untrained, unqualified, inexperienced or unregulated. Some clearly were, but some were highly qualified professionals - psychotherapists, psychologists and even psychiatrists.

Around 14 years ago I took the opportunity of a visit to the UK by the late Campbell Perry, Professor of Psychology at Concordia University, Montreal, to arrange for him to speak at a joint meeting of the British Society of Experimental and Clinical Hypnosis (BSECH), of which I was then secretary, and the BFMS. This was at University College London and was attended by BSECH members, trainees on the Diploma in Applied Hypnosis course at UCL, and members of the BFMS. I had some apprehensions about this meeting as I expected that Professor Perry would give a rather academic lecture on 'recovered memories' (which he did) whereas it seemed to me more likely that what the parents most wanted to hear was how the injustice and damage done to them and their children could be repaired.

One thing that immediately struck me was that these people seemed to come almost uniformly from the professional classes - affluent, educated and articulate. Perhaps this was partly due to selection bias and so on, the meeting being held in central London. Understandably there was a great deal of anger in the air. My colleague H.B. (Tony) Gibson, by then around 80, was in the audience and at one point he attempted to alleviate the tension by suggesting that it wouldn't be long before people would be accused of sexually abusing children in their previous lives. A very irate gentleman stood up and said, 'Excuse me, I have been accused of abusing someone in my previous life - my niece - and it's a damned impertinence!' Indeed, what was most distressing for me at the meeting was realising how badly these people had been let down (to put it mildly) by the psychotherapy profession.

The role of the psychotherapist or counsellor

There is nothing, in my opinion, that is fundamentally at fault with the role of a professional psychotherapist or counsellor. But the occupant of that role is a human being, subject to all the frailties and shortcomings of any other human being. By and large the psychotherapy professions recognise this and a good psychotherapist is self-reflective and self-critical, often with the aid of a third party, his or her 'supervisor'. It is, however, all too easy for the practice of psychotherapy to become detached from any firm scientific base (which should not only inform the ideas and methods employed but also evaluate the outcome of the therapy for the client population). This rejection of science represents an abdication by the practitioners of their responsibility to have some external process of accountability. Elsewhere (note 1) I have described this process as the means by which practitioners of any healing or therapeutic modality (including mainstream medicine) authenticate their roles. The most effective way of achieving this (or its converse) is by scientific evaluation.

In many applied scientific endeavours, especially those that come loosely within the biological and human sciences, there will always be some tension between the theoreticians and academics on the one hand and the practitioners on the other. This can be very healthy and mutually beneficial, but potentially it is the former who threaten the authenticity of the latter, say by revealing that the theoretical assumptions on which the practitioners base their ideas and methods are invalid or that the methods appear ineffective when subject to clinical trials. Practitioners whose ideas and methods are not clearly supported by existing evidence will understandably feel intimidated by the process of scientific evaluation; that is, their role authenticity is threatened. Characteristically they may avoid or dismiss such evaluation and resort to other means of authentication ('We know our treatment works: our patients tell us it does'; 'Our methods have been used for thousands of years'; 'We treat the whole person and you can' measure a whole person'; etc.).

This lack of accountability can be very unhealthy and at times harmful. The practitioners tend to form a closed group, running their own training courses, disseminating their ideas through their own publications, and so on. As such, as a group they come to take on the semblance of a cult, and often there may be one or two influential guru figures whose writings are eagerly digested by their followers and who spend much of their time lecturing and training others in their ideas and practices. Commonly they will assert that no one is qualified to judge or criticise the therapy unless he or she has undertaken the training, which may even involve undergoing a course of the therapy itself (as, e.g., in the case of psychoanalysis).

This kind of 'only we are the experts' mentality is evidenced by those therapists who claim the special ability to detect that a person has suffered childhood sexual abuse from certain signs and symptoms exhibited by the person, even when she or he has no awareness of having been abused. During an invited talk at the 1994 annual BSECH conference in London, the then Director of the BFMS, Roger Scotford (note 2), made a very salient comparison between this claim and the claim of witch hunters in the Middle Ages to be able to identify witches by examining them for particular signs and stigmata

Unchecked by any system of external accountability, ideas and practices may become increasingly extreme and bizarre. It may be very difficult or impossible for the adherents to recognise this: once anyone starts to reject the more advanced ideas, the whole belief system is in danger of unravelling all the way back to its original premise. I have previously referred to this as the 'psychotic phase' of a belief system, by analogy to pathological mental states (note 3), and I shall illustrate it in a moment.

Finally I have identified (op cit) a 'paranoid phase' when the believers interpret the rejection of their ideas and methods as evidence of a conspiracy on the part of some people or organisations (orÂ"'the establishment') to prevent the public from knowing the truth (cf. the idea that the medical profession and the pharmaceutical industry are conspiring, out of self interest, to discredit alternative medicine or that governments are covering up the truth about alien visitations.) I have heard similar 'paranoid' ideas expressed about False Memory Societies that deserve no mention here except with reference to the subject of multiple personality disorder, which I shall now discuss.

Multiple personality or dissociative personality disorder

A feature of the false memory controversy in America - and to some extent in other countries, though less so in Britain - is that many of the clients or patients who 'recalled' memories of sexual abuse were diagnosed by their therapists as having multiple personality disorder (MPD; later relabelled dissociative identity disorder - DID). Putting it very simply, it is claimed that in the face of severe and repeated emotional, physical and sexual abuse, the individual's defence mechanism of repression or dissociation is so profound as to lead to a splitting or fragmenting of his or her personality or self. Thus the person's daily experiences and behaviour may, at any time, be 'under the control' of one of two or more personalities or 'alters' that may not be aware of each other (or awareness may not be mutual). The person diagnosed with MPD or DID may display a range of symptoms and problems that are consistent with this account - e.g. frequent changes of mood and character, extensive memory lapses that cannot be the result of simple forgetting, and little insight into their erratic behaviour.

The diagnosis of MPD or DID is most often made during the course of therapy. The therapist helps the patient identify the attributes that characterise each 'personality' - 'the person in you that's angry', '...afraid', '...hurt', etc. The patient is also invited to provide a name for each one of these and the therapist will ask permission to communicate with the different personalities by asking, say, 'May I speak with John now?', 'Will Mary come out?' or 'Who am I speaking to now?' Thus the patient is encouraged in the therapy session to 'switch' personalities. The aim of therapy is to integrate the personalities into one whole and therefore they are encouraged to communicate with one another. This may happen out of therapy: for example one method is for the patient to put up a bulletin board at home so that the various alters can leave messages for one another.

MPD was once regarded as very rare, even by those who considered it an authentic diagnosis. Then, in the 1980s and 1990s, reported cases increased exponentially in the USA. But not only did the number of people with MPD increase: the number of personalities that any one individual might have also increased, with cases having 100 and even 200 personalities being reported. These personalities were not just 'other people': they might be animals, inanimate objects (I recall that one reported case had a cloud as an alter), previous lives, and so on.

Maybe the reader is now thinking of my idea of the 'psychotic phase'? And what about the 'paranoid phase'? In America, the CIA has been cited as being in cahoots with the False Memory Foundation and the backlash against the diagnosis of multiple personality disorder. Why the CIA? Because one theory is that after World War II, American Intelligence was involved with Nazi doctors in the programming of children to develop multiple personality disorder. These ideas have been espoused not by some oddball in a Breakfast Television interview but by a Professor of Psychology at the University of Utah who informed us, 'My best guess is that the purpose of it is that they want an army of Manchurian candidates - tens of thousands of mental robots who will do prostitution, do child pornography, smuggle drugs, engage in international arms smuggling, do snuff films, all sorts of lucrative things and do their bidding. And eventually, the megalomaniacs at the top believe (they will) create a satanic order that will rule the world'(note 4).

The British public have displayed a robust immunity to MPD. There are a number of reasons for this. I believe one of them is that the psychoanalytical influence on mainstream psychiatry has traditionally been much stronger in the USA than in Britain. Associated with this is the fact that American psychiatrists and psychologists make much greater use of the concept of dissociation in clinical practice than their British counterparts (at least this is my impression; note 5). Another reason may be that the diagnosis of serious mental disorders is usually the domain of psychiatrists who, in this country, tend not to undertake psychotherapy with their patients. It is likely that here, the preferred diagnoses for patients presenting with severe symptoms are schizophrenia, bipolar affective disorder, and borderline personality disorder.

At a scientific meeting I once asked the late Professor Sidney Brandon (senior author of the 1997 Royal College of Psychiatry's Report on 'recovered memories') why, unlike recovered memories of childhood abuse, there has been no 'epidemic' of MPD in this country. His reply was 'We don't allow our patients to have it!' What he meant was that when patients start to talk as if they have different identities the professionals looking after them do not collude with this to the extent of turning the metaphorical into the literal.

This approach is consistent with the majority view in the UK, supported by many professionals in other countries, including in fact the USA, namely that MPD or DID is mainly or wholly iatrogenic and results from the explicit and implicit coaching of patients by the therapist into this way of thinking of themselves and their problems in life.

Speaking for myself, 37 years of professional work as a psychologist has rewarded me with not one single encounter with anyone with MPD or DID. In the last 8 years I have worked with offenders with mental illnesses and personality disorders serious enough to warrant their being compulsory detained under the Mental Health Act. More often than not they have endured childhoods of extreme emotional deprivation, often blighted by severe physical and sometimes sexual abuse. This is the very population in which one would expect to find patients who might be diagnosed with DID. Yet on no occasion has this diagnosis been seriously entertained. Rarely is the concept of dissociation itself invoked in any formal diagnostic usage, though we use it now and again in its more everyday descriptive sense (and would probably use it more frequently if we had more patients with severe personality disorders). We do find the concept of 'fragmented personality' useful to understand the mental states of some acute patients on admission. Such patients seem to lack a consistent core personality or 'ego' in the Freudian sense. Their behaviour and emotions and the demands they express are wildly erratic and difficult to make sense of both to themselves and to the staff. But no reference is necessary to multiple personalities: with the proper medication and their containment in the stable and caring environment of the hospital, and free from malign influences, not least amongst these being street drugs, these patients calm down and their 'true' personality gradually emerges from the chaos.

More thoughts on the British False Memory Society

I have absolutely no doubt that, like my own, the sympathy of ASKE members lies overwhelmingly with the parents and families whose interests the BFMS represent. The majority of the media is naturally supportive too and this makes the BFMS a powerful voice. It boasts an impressive Scientific and Advisory Board, mainly consisting of prominent academic figures in the field of Psychology. The Newsletter itself contains, amongst other features, academic papers of high quality, two of which are reprinted in this issue of the Skeptical Intelligencer. This is one reason why it strikes me as an unusual Newsletter, since I assume that its main target readership, the BFMS membership, is largely composed of people who have no academic interest in, or specialised knowledge of, human memory.

But it is unusual because of more than this. The BFMS is informed by one campaigning principle: a statement about the nature of human memory, and a negative one at that, namely that it is not possible for people to repress memories of major traumatic events or episodes that can later be rendered accessible again by psychological means. Putting it somewhat baldly, this means that any potential instances of people allegedly displaying recovery of repressed memories must be immediately discredited. Some authorities may go along with this, some may not; and some lay people may claim that they have indeed rediscovered extensive 'repressed' memories. This intensifies the politics of the debate somewhat.

This antithesis to the idea of 'repression' is evidenced in the Newsletter by an undercurrent of sensitivity or hostility to related subjects such as psychotherapy and counselling generally, psychoanalysis in particular, everything Sigmund Freud said and did, dissociation, psychogenic amnesia in general, hypnosis, post-traumatic stress disorder, and most recently (March 2007, pp 18-19) the Government's concern about the low rates of conviction (more accurately, indictment) in allegations of rape. Understandably this hostility sometimes manifests itself in ad hominem attacks on individuals, even just for seeming, in their writings, to have some sympathy with the possibility of dissociative amnesia. The risk of this is that critics of the BFMS may accuse them of the same 'witch-hunting' devices as they ascribe to therapists who claim expertise in identifying the sexually abused patient.

Occasionally I read in the Newsletter a statement to the effect that the validity of repression and recovered memories is the biggest controversy in psychiatry today. Few people who work in NHS general psychiatry would agree with this statement. In my years of clinical practice I have only known one patient, whom I shall describe shortly, for whom 'recovered memories' of sexual abuse was an issue. I do not recall ever being informed by a work colleague about any such case or the matter ever being raised at ward rounds, case conferences and so on. The last time I gave a presentation to work colleagues that touched upon recovered false memories there seemed to be very little awareness of this issue in the audience, and the unit manager, who had had many years' experience in psychiatric nursing, asked me to lend him a book on the subject.

My own experience of 'recovered memories', 'psychogenic amnesia', etc.

Have I ever intentionally elicited 'repressed memories' in my work as a clinical psychologist and practitioner of hypnosis? No. Even before the contemporary false memory controversy came to the fore I was never comfortable with the idea of directly suggesting to patients that there may be some'hidden memory' that needs to be restored to consciousness in order for them to resolve their problem. One danger of this is that the patient may feel obliged to come up with some memory - or even a fantasy - that will satisfy the demands of the therapist.

There are plenty of case reports in the literature of 'recovered memories' that immediately raise these kinds of doubts. For example, in one account a man with torticollis ('wry neck') relived the memory of suddenly turning away in disgust from a plate of meat that had gone rotten and was infested by maggots. This was supposed to be the event that had precipitated the torticollis but the author had no supporting evidence and it did not appear that recalling it itself (if indeed the man had 'repressed' it at all) alleviated the man's condition.

At conferences I have occasionally listened to case presentations by colleagues who have elicited the memory of a (usually childhood) experience that supposedly 'lay at the root' of the client's problem. The problem resolves once the memory is 'relived', sometimes with considerable emotion. (I can't recall an instance of a 'recovered memory' of sexual abuse; I do recall one speaker who appeared to attach some significance to his patient's exclaiming 'Poppycock!' at any idea that her father had abused her.) This is not to say that it can be quite profitable, therapeutically, to encourage patients to revisit difficult memories, so long as some kind of resolution is effected.

The one case of apparent recovered memories of sexual abuse that I recall seeing in my clinical practice was a man I had been treating with cognitive behaviour therapy for depression who had done well and the course of therapy was drawing to a close. Then, for several weeks, he came to the sessions with notes that he had written describing vivid flashback experiences he was having of being abused by a now deceased family member. It was difficult for both of us to understand what was happening, although he himself had previously described similar vague memories. At that time, concern was beginning to be expressed in the media about false recovered memories, so he did raise the question of the validity of these 'memories'. It was puzzling to both of us why, all of a sudden, he was experiencing any of this. He had recently been working with disturbed children, some of whom had been abused, so this might have been a trigger.

I also recall that about 25 years ago I was referred a patient who told me a long story about how recently he or she (I can't even remember which now) had recalled 'forgotten memories' of being sent away to be fostered as a child for a certain period (I can't remember for how long but it wasn't just a matter of days or weeks). This person told me in detail about his or her life as a foster child and we arranged a further interview but the person did not attend any more sessions.

In my experience in the adult mental health services generally, I have known two patients who described extensive retrograde amnesia of possible psychological origin; neither of them was convincingly dissociative. It is true to say that opinion in this country is divided as to whether, in the absence of any evidence of brain injury, such individuals are consciously aware of their apparent 'lost memories', though a general scepticism prevails. The first of the above case was about 30 years ago when a man was admitted to the psychiatric unit where I worked, averring that he did not know who he was and had no memories of his life. His amnesia resolved when his true identity was finally established and it transpired that his bank manager was keen to speak to him. The other case was referred to me by a neurological unit with a world-class reputation for specialising in organic amnesic conditions. All this patient's brain scans were normal. Despite my efforts to help her, she did not regain the extensive autobiographical memories that she had lost (she was not totally amnesic for these). I remain convinced that her condition was neurological in origin.

In my forensic work I have occasionally given opinions on complainants of indecent assault and rape where the defence has questioned whether false memory could be at work. In all but one of these cases the people were claiming to have been assaulted as adults. Even in such cases, I believe that there may be a recent tendency for defence lawyers, for no compelling reason, to seize upon the idea that such an accusation may be a 'false memory' on the complainant's part.

In fact, in the bulk of the cases in which I have provided evidence (always in written form) the complainants have been patients or clients of doctors, psychologists, therapists of various sorts and so on, who, it is alleged, sexually assaulted them during a session of hypnosis or some kind of relaxation procedure. I have written accounts of this work elsewhere (notes 6 and 7). In the last case I was involved with, several women complained that an osteopath had sexually assaulted them during treatment (which in most instances appeared to be some form of aromatherapy; hypnosis was not used). Their testimonies were in the main very similar to those of previous cases I have examined and were very plausible. The defence hired their own expert, someone on the BFMS Scientific and Advisory Board, who opined that the women's accounts might constitute false memories or be the result of their placing a sinister interpretation on the defendant's innocent behaviour. The latter may constitute a plausible account in some cases, but in my experience, the false memory defence can only be seriously entertained in rare cases of this kind. Video evidence from covert surveillance of the osteopath at work left little to the imagination and he was sent to prison for several years.

I have seen one adult complainant who alleged sexual abuse by her father when she was in her earliest years. Her 'memories' for the events at such an early age were far too detailed to be authentic. But it was not a straightforward case: she did say she had always remembered being abused, but lately she had been experiencing nightmares and flashbacks. She had gone to a hypnotherapist who 'regressed' her and I had to agree with the prosecution psychiatrist that her evidence was not reliable.

Also in forensic practice I have occasionally seen a defendant who claims amnesia for a violent crime such as murder or rape and where the amnesia cannot be accounted for by intoxication with alcohol or drugs or some condition of the brain. The claimed amnesia is usually quite extensive. (There is a phenomenon that has been labelled 'red-outs' in the literature that refers to amnesia for a period of a few seconds during which, overcome by intense rage, the accused person has committed a violent assault. 'State-dependent memory' has been invoked to account for such amnesia but I am not convinced by this explanation.)

There is a healthy scepticism on the part of forensic psychiatrists and psychologists in this country about more extensive claims of amnesia, but my impression is that many professionals seem comfortable with the idea that, for example, a man claiming to have no memory of committing a violent murder may be genuine and may, in the fullness of time (usually while serving his sentence) begin to remember the event. This was the opinion of a psychiatrist who assessed a man who was charged with (and who eventually pleaded guilty to) the brutal murder of a child and the attempted murder of her mother. The scene of the crime bore all the evidence of a frenzied attack, but the defendant claimed amnesia for an extensive period, which included anything that might have precipitated the attack. I was doubtful about his claim when I saw him for a pre-trial report but I still have an open mind. I have no experience of any convicted person exhibiting 'recovered memories' of this nature and hope one day to research this subject.

Is there anything special about traumatic memories of child sexual abuse?

Those who are antagonistic to the idea of repressed memories of childhood abuse, often employ the argument, used by McNally, 2006, as quoted in the Ost and Wade paper '....survivors of trauma generally find it difficult not to think about the events they have witnessed'. A striking example is that of Holocaust survivors, including those who were children at the time, who have all-too-vivid memories of their ordeals.

I have assessed, for medico-legal purposes, hundreds of people who have suffered some degree of trauma due to an accident. In most cases the trauma is mild relative to that experienced by, say, soldiers on active service or people who have been violently attacked. I cannot recall any convincing case of repressed memory in the absence of head injury, except possibly only for very brief periods of acute shock (e.g. 'The next thing I remember was lying on the ground, but I can't remember actually getting out of the car.') However, we do need to acknowledge the fact that adult memories of the trauma of being sexually abused in childhood present a more complex picture.

Let me explain further. Unlike, say, a Holocaust victim, the child who is being sexually abused is on her own (I shall use the feminine for simplicity). She has not the knowledge or maturity to understand or make proper sense of what is happening (unlike when, later on in life, she considers the events from an adult perspective). She has very confused feelings about it and, importantly, these commonly include shame and guilt. There is usually considerable denial about what is happening or has happened. The perpetrator is often a trusted person who spins a web of deceit about what is taking place. A child often does not tell anybody and does not hear a proper explanation that she can understand. If the child does tell somebody, such as her mother, she may be informed that she is lying or mistaken and that the event or events never occurred. In the case of extensive abuse, some children learn to detach themselves from what is going on and create a fantasy life in which such terrible things do not happen. Over the years, the person may indeed develop strategies of trying not to think about what happened. All these factors have implications for the person' memory of the events as the years go by. Of course none of this implies that an over-simplified notion of 'repressed memory' has any validity. However, it does mean that the comparison with other kinds of traumatic experiences is not so straightforward. I would like our academic colleagues to pay more heed to this and to give us the benefit of their expertise concerning the implications for how the events in question are recalled.

Posthypnotic amnesia

The paper reviewed by Ost and Wade in this issue is about 'directed forgetting', when participants are instructed to try to forget some material presented to them. What about posthypnotic amnesia (PHA)? We should consider two kinds, spontaneous and suggested. Spontaneous PHA (total or partial amnesia for events that happened during hypnosis) has a long documented history and at times it has been considered the defining characteristic of true hypnosis. For the amnesia to be real it must be clear that the subject was responding, or at least attending, to the events at the time. A complete spontaneous amnesia is rare but can happen and the subject will usually recall the events with prompting. My experience and the results of one investigation by Crawford et al. (1992) (note 8) suggest that the incidence of spontaneous PHA is higher for stage hypnosis subjects than for laboratory subjects. The blanket amnesia reported by one of Crawford et al.'s subjects could not be breached by prompting. I once assessed a man claiming damages against a stage hypnotist who, nearly 5 years after the event, still had minimal recollection of the entire show in which he took part. He also described marked time condensation, the whole show seeming to last just a few minutes, when in effect it went on for one and a half hours according to his friends. In criminal cases known to me of alleged sexual assault during hypnosis, once in a while a complainant claims amnesia for the actual assault; one complainant claimed that the amnesia lifted over several hours but I offered what I considered to be a more likely interpretation in my report. I usually advise that any account of such events where some amnesia is reported should be treated with caution.

When it comes to hypothesising about the cognitive processes associated with spontaneous PHA I find the literature disappointing, and mainstream explanations (e.g. expectancy and state-dependant memory) unconvincing. The phenomenon is taken by some as indicating that at least a proportion of hypnotic subjects are in an altered state of consciousness, by analogy with the common occurrence of amnesia for dreams on wakening. The late Professor T.X. Barber, who spent decades debunking the notion that hypnosis was a special state, finally conceded (note 9) that there is a small proportion of highly susceptible people who appear to resemble the traditional 'deep trance' subjects when they undergo hypnosis. He described them as 'amnesia prone' (he baulked at using the term 'dissociation'). These individuals exhibit confusion and amnesia when alerted from hypnosis and they report having amnesic episodes in their everyday life. They have limited memory of their childhood, unlike the small proportion of highly hypnotisable subjects who are described as 'fantasy prone'. They also have histories of severe physical, and sometimes sexual, abuse in childhood. The bulk of highly hypnotisable subjects are, according to this analysis, neither 'amnesia prone' nor 'fantasy prone'; they are described as having positive expectations and motivations about hypnosis. These categories have not received universal acceptance.

What about suggested PHA? The suggestion is that the participant will not recall the contents of the hypnosis session or some specific information until he or she is alerted from hypnosis and not until the hypnotist has provided a signal - the 'reversal cue', which the hypnotist specifies - for the memories to return. Hence, by definition, PHA is reversible: the memories are retrievable, not unencoded or erased.

The material to be forgotten may be items learned or experienced during hypnosis or information learned prior to hypnosis such as word lists and even autobiographical events. Many, though not all, responsive subjects experience the amnesia as involuntary. The amnesia may be complete, partial or absent and this is related to the subject's measured suggestibility. Highly suggestible subjects may experience total amnesia for the targeted material.

Traditionally, suggested PHA is conceived of as something that happens to the subject but it is much better to think of it as something the subject does, even those responsive subjects who describe the experience as involuntary. That is, they retain ultimate control over their memory processes. The reversal cue is an indication to the subject that he or she is to 'stop being amnesic', but the amnesia is usually relinquished under strong pressures to be honest (e.g. by producing a 'lie-detector') or other cues that imply that recall of the material is now expected. This probably applies to responding to posthypnotic suggestions in general.

Although it appears that responsive subjects are consciously unable to recall the target material, its 'presence in memory' is manifested implicitly. For example, in contrast to their reaction to new material, subjects show a galvanic skin response (sweating) when presented with items from a previously presented word list for which they deny any conscious recall. Such material still has the potential to interfere with the subject's learning of new material that is not included in the amnesia suggestion. Indeed the targeted material, while seemingly not available for explicit recall, nevertheless is manifest in a range of indices of implicit memory such as word associations and the completion of word fragments.

As well as dissociation, mechanisms that have been proposed to underlie suggested PHA include compliance (i.e. the subject is knowingly pretending) and distraction strategies during recall. It seems that some responsive subjects do employ these tactics, but highly suggestible, highly responsive subjects seem adept at inhibiting retrieval of the targeted material by some kind of pre-conscious mechanism (which some would identify as dissociation) that is different from those mechanisms adopted by subjects directly instructed to forget the material (David et al., 2000; see note 10). Consistent with this are the findings of a recent brain-scan investigation of the neural correlates of suggested PHA in highly suggestible subjects (note 11). (For a recent review of PHA see Mazzoni, Heap & Scoboria, in press; note 12.)

Final thoughts

We habitually talk about memories as though they are things we have. But there are no such things as memories; they do not exist as entities. They are activities we do. In a previous paper (note 13) I made the analogy with waving my hand; I can refer to 'the wave' but 'When I stop waving my hand the wave does not go somewhere'. Thus, I engage in the act of remembering an event; when I stop doing this the memory does not go somewhere. It is not stored away like a file in a filing cabinet. Just as my hand, arm and nervous system are structured in a manner that allows me to engage in the act of waving when I choose, so my brain is structured in a manner that allows me to recall a particular event when I chose. In fact, the same can be said of thinking, imagining, dreaming, and anything that the brain does, including the mind: the mind is something the brain does.

Likewise, instead of asking 'Is there such a thing as repression?' or 'Does repression exist?', we would do better to phrase the question in the active form, something like: 'In what ways are people able to inhibit the activity of consciously recalling an event?'

It does not appear that the processes involved in 'directed forgetting' or in deliberate attempts to inhibit recall match those associated with suggested PHA, although they may do in some subjects. Some authorities consider that suggested PHA is similar to functional amnesia, notably because of the differential effects on explicit and implicit memory. Whatever the case, PHA appears to be something that highly hypnotisable individuals are adept at doing and reversing according to context (the instructions, the cues, the expectations created, and so on). There is no theoretical reason why responsive individuals should not be able to do this outside of the hypnotic context.

Is this the same as saying that we have here a mechanism for the repression of traumatic childhood substantial memories claimed by some therapists? I don't think so. Neither does Professor John Kihlstrom of the University of California, Berkeley, a leading specialist on PHA and advocate of the dissociation model, but an antagonist when it comes to the notion of the wholesale repression of traumatic memories (note 14). It is however consistent with the idea that some responsive individuals can, in some contexts, be temporarily amnesic for events and information that normally they are able to recall. This notion is used to describe pathological dissociative states but it could be a more everyday phenomenon.

Notes and references

1. Heap, M. (2002) Healing and therapy in the age of mass affluence. The Skeptical Intelligencer, 5, 3-2. (Also available at www.mheap.com).

2. Scotford, R. (1995) Myths, memories and reality. Contemporary Hypnosis, 12, 137-142.

3. Heap, M. (2002) Psychopathology and beliefs in anomalous phenomena. The Skeptical Intelligencer, 4, 5-16. (Also available at www.mheap.com).

4. http://www.fmsfonline.org/hammond.html

5. Loosely speaking, dissociation is when experiences or cognitive activities that one would normally expect to be available for conscious expression are not so; or when two or more incongruent activities or experiences occur in parallel without the person acknowledging their incongruity, as when a functionally blind person avoids colliding with objects in an unfamiliar environment.

6. Heap, M. (2006) Assessing allegations of sexual assault during hypnosis and related procedures. Australian Journal of Clinical and Experimental Hypnosis, 34, 41-54.

7. Heap, M. (2008) Hypnosis in the courts. In M. Nash & A. Barnier, The Oxford Handbook of Hypnosis (pp. 745-766). Oxford: Oxford University Press.

8. Crawford, H.J., Kitner-Triolo, M., Clarke, S.W. & Olesko, B. (1992) Transient positive and negative experiences accompanying stage hypnosis. Journal of Abnormal Psychology, 101, 663-667.

9. Barber, T.X. (1999) Hypnosis: A mature view. Contemporary Hypnosis, 16, 123-127.

10. David, D., Brown, R., Pojoga, C. & David, A. (2000) The impact of posthypnotic amnesia and directed forgetting on implicit and explicit memory: New insights from a modified process dissociation procedure. International Journal of Clinical and Experimental Hypnosis, 48, 267-289.

11. Mendelsohn, A., Chalamish,Y., Solomonovich, A. & Dudai, Y. (2008) Mesmerizing memories: Brain substrates of episodic memory suppression in posthypnotic amnesia. Neuron, 57, 159-170.

12. Mazzoni, G., Heap, M. & Scoboria, A. (in press) Hypnosis and memory. In J.W. Rhue, S.J. Lynn, I. Kirsch (Eds). Handbook of Clinical Hypnosis. Washington DC: American Psychological Association Press.

13. 'Let's wave goodbye to the unconscious mind' at www.mheap.com

14. http://socrates.berkeley.edu/~kihlstrm/traumarejoinder.htm