Thursday, 22 November 2012

Déjà vu & dream precognition

I constantly have dreams of a ‘Dream Town’ – which are recorded in this Blog. As previously explained, this ‘town’ feels familiar, homely – as if it is a real-life memory of a place I have visited before. However, the town I dream of does not seem to relate to any actual location I have lived in, or can remember visiting. One dream revealed the town name to possibly be Sudbury/Sudsbury – the name of two actual places in England, although I have been to neither and internet research revealed neither location corresponds to my dream experience. In other dreams, a recurrent theme is me attending a university or college in this ‘dream town’ – although the campus is nothing like either university I have actually attended. I really enjoy dreaming of this town, although I am left confused by the strength of my consistent, recurrent memories of somewhere I can’t actually recall or identify in my waking life. My fascination with this element of my dream experience led me to research the phenomena of déjà vu and precognitive dreaming. 

Psychologist Edward B. Tichener in A Textbook of Psychology (1928) explains déjà vu as an experience in which a person has a brief glimpse of an object or situation prior to the brain having completed a ‘construction’ of a full conscious perception of the experience. This ‘partial perception’ results in a false sense of familiarity – thus, an anomaly of memory (false impression of actual recall), as opposed to an act of ‘precognition’ or ‘prophesy’. The experience of déjà vu means that the sense of ‘recollection’ at the time is particularly compelling, but the circumstances of ‘previous experience’ (the event upon which the ‘memory’ is based) are perceived as uncertain or impossible to have actually occurred. The subject may exhibit a strong recollection of having the somewhat unsettling experience of déjà vu itself, but absolutely no recollection of the specifics of the events ‘remembered’, which results in an ‘overlap’ between the neurological systems responsible for short-term memory and long-term memory. This results in memories of recent events being erroneously perceived as having occurred in the past. One theory explaining this phenomenon suggests that events are stored in the memory before the conscious part of the brain is able to receive the information and correctly process it. Criticism of this theory points out that the brain is unable store information without a prior sensory input. Another theory suggests that the brain may process sensory input as a ‘memory-in-progress’ and that during the event itself, a person believes it to be a past memory. In a survey, Brown (2004) concluded that approximately two-thirds of the population has experienced déjà vu. 

Other theories of déjà vu also assert that this phenomenon is the result of a flaw in the functioning of the short-term/long-term memory stores. The basic idea is that there are portions of the brain that are specialised for the past, the present and the future. In general, the frontal lobes are concerned with the future; the temporal lobes are concerned with the past; and the underlying, intermediate portions (the limbic system) are concerned with the present. When these elements of the brain are functioning normally, in normal states of consciousness, the feeling that ‘something is going to happen’ will only come up when we are thinking about the future - worrying about it, anticipating it or making plans for it. The sense of the past will only come up when our memories have been triggered in some way. The structure that controls our consciousness when we are 'in the present are is the amygdale, which assigns an emotional 'tone' to our perceptions. The amygdala also recognises and processes the expressions on people's faces. Certain phrases or words evoke feelings of imminent danger and require appropriate responses, and the amygdala is specialised to provide them. For example, one mental function it participates in - the maintenance of the sense of self - is repeated 40 times per second. Each instance of the ‘self’ is able to manifest a new emotional response, but only if circumstances have changed - every 25 milliseconds. In fact, the duration of the 'present' in neurological terms is so brief that we don't experience it so much as remember it.

Short term-memory deals in periods of a few minutes and is mostly based in the hippocampus. We know this because problems with the hippocampus often lead to severe short-term memory problems. It helps us to stay oriented in time and function effectively – for example, hold a conversation, remember what we have just done or where we have been etc. 

Then there is long-term memory, which is 'seated' in the surface of the brain, along the bottom of the temporal lobes. The area has been called the parahippocampal cortex, and it is very closely connected to the hippocampus. Ordinarily, there is a fairly seamless integration of the past, present and the future. In simple terms, we experience something in the present, compare it to similar experiences in the past, and then decide how we will respond. The time frame can be very brief - even a few seconds. Once in a while, though, there can be too much communication between short-term and long-term memories. When this happens, then the present can feel like the past. If perceptions from the present are shunted through the parts of the brain that process memories from the past, those perceptions will feel like they are memories, and the person will feel that they are re-living a moment stored in long-term memory – i.e. déjà vu.

Early researchers tried to establish a link between déjà vu and serious psychopathology such as schizophrenia, anxiety, and dissociative identity disorder, but failed to find any diagnostic value. There does not seem to be a special association between déjà vu and psychiatric conditions. The strongest pathological association of déjà vu is with temporal lobe epilepsy - this correlation leading some researchers to speculate that the experience of déjà vu is possibly a neurological anomaly related to improper electrical discharge in the brain. As most people suffer a mild (i.e. non-pathological) epileptic episode regularly (i.e. a hypnagogic - the sudden ‘jolt’ that frequently, but not always, occurs just prior to falling asleep), it is conjectured that a similar (mild) neurological aberration occurs in the experience of déjà vu, resulting in an erroneous sensation of memory. Scientists have even looked into genetics when considering déjà vu. Now they may never find a gene for déjà vu, but one particular gene and its inheritance patterns do intrigue scientists. The gene's name is LGII. It lies on chromosome 10. Certain forms of the gene are associated with a mild form of epilepsy. Though by no means a certainty, déjà vu occurs often enough during seizures that researchers have reason to suspect a link. Certain drugs increase the chances of déjà vu occurring in the user – for example, some pharmaceutical drugs (when taken together) have also been implicated in the cause of déjà vu. Taiminen & Jääskeläinen (2001) reported the case of an otherwise healthy male who started experiencing intense and recurrent sensations of déjà vu upon taking the drugs amantadine and phenylpropanolamine together (to relieve flu symptoms). Due to the dopaminergic action of the drugs and previous findings from electrode stimulation of the brain (i.e. Bancaud et al 1994) Taiminen & Jääskeläinen speculate that déjà vu occurs as a result of hyperdopaminergic action in the mesial temporal areas of the brain. The similarity between a déjà vu eliciting stimulus and an existing (but different) memory trace may lead to the sensation of déjà vu. Thus, encountering something which evokes the implicit associations of an experience or sensation that cannot be remembered, may lead to déjà vu. In an effort to experimentally reproduce the sensation, Banister & Zangwill (1941) used hypnosis to give participants posthypnotic amnesia for material they had already seen. When this was later re-encountered, the restricted activation caused thereafter by the posthypnotic amnesia resulted in 3 of the 10 participants reporting what the authors termed ‘paramnesias’. 

Memory-based explanations may lead to the development of a number of non-invasive experimental methods by which a long sought-after analogue of déjà vu can be reliably produced that would allow it to be tested under well-controlled experimental conditions. Cleary (2008) suggests that déjà vu may be a form of familiarity-based recognition (recognition that is based on a feeling of familiarity with a situation) and that laboratory methods of probing familiarity-based recognition hold promise for probing déjà vu in empirical research. A recent study that used virtual reality technology to study reported deja vu experiences supported this idea. This virtual reality investigation suggested that similarity between a new scene's spatial layout and the layout of a previously experienced scene in memory (but which fails to be recalled) may contribute to the deja vu experience. When the previously experienced scene fails to come to mind in response to viewing the new scene, that previously experienced scene in memory can still exert an effect – i.e. a feeling of familiarity with the new scene that is subjectively experienced as a feeling of déjà vu, or of having been there before despite knowing otherwise. Another possible explanation for the phenomenon of déjà vu is the occurrence of ‘cyptomnesia’ - which is where information learned is forgotten but nevertheless stored in the brain and similar occurrences invoke the contained knowledge, leading to a feeling of familiarity because of the situation, event or emotional/vocal content. Some experts suggest that memory is a process of reconstruction, rather than a recall of fixed, established events. This reconstruction comes from stored components, involving elaborations, distortions and omissions. Each successive recall of an event is merely a recall of the last reconstruction. The proposed sense of recognition (déjà vu) involves achieving a good ‘match’ between the present experience and our stored data. This reconstruction however, may now differ so much from the original event that we ‘know’ we have never experienced it before, even though it seems similar. Some parapsychologists have advocated other interpretations of déjà vu. Fisher (1984), Ian Stevenson (1987) and other researchers have written that some cases of déjá vu might be explained on the basis of reincarnation. Anthony Peake (2012) has written that déjà vu experiences occur as people are living their lives not for the first time but at least the second.

The phrase ‘jamais vu’ is derived from the French, meaning ‘never seen before’. It is used to describe something highly familiar to the subject, which is not recognised, and is perceived as being experienced for the very first time, despite the subject rationally knowing that they have been in the same situation before. The subject momentarily fails to recognise something they already know. Jamais vu is sometimes associated with certain types of aphasia, amnesia, and epilepsy. Theoretically, as seen below, a jamais vu feeling in a sufferer of a delirious disorder or intoxication could result in a delirious explanation of it, such as in the Capgras delusion, in which the patient takes a person known by him or her for a false double or impostor. If the impostor is himself, the clinical setting would be the same as the one described as depersonalisation, hence jamais vus of oneself or of the very ‘reality of reality’, are termed depersonalisation (or surreality) feelings. Presque vu is similar, yet distinct from the phenomenon which is commonly referred to as ‘tip of the tongue’ syndrome (where a word or memory is just beyond the reach of the subject trying to remember and has to be ‘mined’ for). Presque vu translates as ‘almost seen’ and is an experience described as a sensation of being on the brink of an epiphany. Déjà entendu means ‘already heard’; whereas reja vu is the feeling that something has happened or is imminent. 

Déjà vu in dreams is often written about in conjunction with ‘precognition’, but the two are very distinct concepts. In parapsychology, ‘precognition’ translates from the Latin prae (before) and cognito (acquiring thought) – and is also referred to as ‘future sight’ or ‘second sight’ – an extrasensory perception (ESP) by which the subject perceives knowledge or insight which cannot be obtained from present sensory, environmental or natural sources. A ‘premonition’ and ‘presentiment’ are types of knowledge/information about future events which is perceived as an emotional response. The existence of these types of ESP is controversial and has not been empirically proven and indeed, concepts such as precognition violate the laws of physics which state that an effect cannot occur before its cause.  Many of the "psychic experiences" that are volunteered to parapsychologists by the general population involve apparent precognition. In one review of an American case collection, submitted to Duke University's Parapsychology Laboratory by Stokes (1997), 75% of 1777 dream-based experiences were of an ostensibly precognitive type, as were 60% of 1513 wakeful experiences. A similar pattern was identified by Drewe (2002) for a separate collection of 157 cases experienced by children - here, the largest category of experiences was again of precognitive dreams (52%), followed by precognitive intuitions (52%). A German case collection by Sanwald (1959) produced a similar figure: 52% of 1,000 cases were of the apparently precognitive type and a British study by Green (1960) of 300 volunteered cases showed 34% to be apparently precognitive. In another survey more than half of the respondents (50.4%) reported having precognitive dreams; nearly one-fourth (44.7%) reported having multiple precognitive dream experiences; and many (30.9%) are aware they are having a precognitive dream as they dream it and know that such dreams are precognitive because they are more vivid or real; they ‘feel different’ or are experienced as ‘short, precise and vivid’.

Precognition is believed to be a form of future vision – seeing into the future before it happens (either by waking visions, déjà vu or dreams, the latter being the most common type of precognitive experience). JW Dunne, a British aeronautical engineer, recorded each of his dreams as they occurred to him, identifying any correspondences between his future experiences and his recorded dreams. In 1927, he reported his findings, together with a theory, in An Experiment with Time. He concluded that at least 10% of his dreams appeared to represent some future event, pertaining to some relatively trivial incident in his own life, or some major news events appearing in the press a day or so after the dream. Dunne concluded that precognitive dreams are common occurrences - many people have them without realising it, largely because they do not recall the details of the dream. Also reported in the book was an experiment Dunne conducted with several other people who studiously recorded their dreams and sought to associate them with subsequent experiences. Dunne felt these confirmed his theory, but a 1933 independent experiment by Besterman failed to replicate his findings. With ‘free-response’ methods, experiments have been conducted by Krippner et al (1972) in precognitive dreaming at the sleep laboratory of the Maimonides Medical Center in precognitive Ganzfeld (a form of sensory deprivation situation) hallucinations and visions. While such experiments have produced some suggestive evidence for precognition, they have been somewhat limited to studies of selected participants, and have involved procedures that can be too expensive for other researchers to replicate, or too complex to theoretically interpret. Most experiments involve a ‘forced-choice’ procedure - the first such ongoing and organised research program on precognition was instituted by JB Rhine in the 1930s at Duke University's Parapsychology Laboratory. Another class of experiments has tested for precognition by unconscious signs. These have involved physiological responses, such as of skin conductance and electroencephalographic activity, or indirect psychological measures, such as ratings of preference for one or another target alternative. In these experiments, participants are not asked about their experiences, and do not need to be informed that they are participating in an experiment on ESP. Dick Bierman & Dean Radin (1997, 1999) have reported positive evidence of precognition in experiments of these kinds.

Various psychological processes have been used to explain the phenomenon of precognition:
  1. Selection/memory bias – subjects remember ‘successes’ and forget ‘failures’
  2. Unconscious perception – subjects unconsciously infer (from information that they have unconsciously learned) that a specific event is likely to occur in certain circumstances. As with cryptomnesia, when the event occurs, the former knowledge appears to have been acquired without the aid of recognised channels of information
  3. Self-fulfilling prophesy/unconscious enactment – the subject brings to pass ‘precognized’ events without conscious awareness of their own agency
In one experiment by Alcock (1981), subjects were asked to write down their dreams in a diary, preventing the selective memory effect (by which the dreams are retrospectively ‘fitted’ onto subsequent real-life events) and the dreams no longer seemed accurate about the future. Another experiment by Madey (1993) gave subjects a fake diary of a student with apparently precognitive dreams. This diary described events from the person's life, as well as some predictive dreams and some non-predictive dreams. When subjects were asked to recall the dreams they had read, they remembered more of the successful predictions than unsuccessful ones.

Precognition can be conceived as an extraordinary process of clairvoyance, involving no direct perception of the future. If, as is offered by the philosophy of determinism, all future events are determined by present conditions, then it can be suggested that it is clairvoyance of all the relevant present conditions that permits one to know their future outcomes. Alternatively, if somebody in the present is aware of what will happen in the future, then it can be suggested that it is telepathy of that information that grants oneself a like knowledge of the future. ‘Seeing into the future’ can also be conceived as not a direct perception of a future event, but only a perception of one's own future experience of that event - Rhine called ‘precognitive sensory perception’. Support to this suggestion is given by the meta-analysis which includes the study of a subset of experiments in which details were provided about the feedback of target information given to subjects in the future. The study shows that when no feedback was given, the significance of the results fell to chance-expectation. This does suggest that the contacts were being made with the subject's future experience of receiving the target information, and not with the targets themselves. The construct of psychokinesis permits another paradigm with which to consider precognition. It can be suggested that precognition involves the ‘influence’ of present conditions so that they conform with what is precognized. Alternatively, a retro-causal process can be proffered as an explanation, raising the idea that, at a future time, the ostensibly present conditions are influenced backward in time. As for theories of precognition itself, parapsychologists have offered several phenomenological theories that – like most psychological theories themselves – do not presume to provide a physical explanation of how precognition occurs, but only seek to describe the processes which are occuring. There are two classes of such theories, which are not exclusive to each other. The first is subliminal awareness, discussed separately and distinctly, by Dunne (1927) and Saltmarsh (1938). This supposes that awareness is fundamentally trans-temporal, acquiring information beyond the ‘specious present’ of information that is typically available for immediate awareness.  While we are only ever consciously aware of some limited temporal range of information, these theories assert that, unconsciously, a much wider temporal range of information is sampled and used for the benefit of the organism or subject. The second class of theory is influenced by Gerald Feinberg's concept of a tachyon (particles that travel faster than light). Some parapsychologists such as Martin Ruderfer (1974) theorised that tachyons can travel backwards in time and may be able to explain cases of precognition. The British physicist and mathematician Adrian Dobbs (1965) proposed a theory in which precognition occurs due to ‘positrons’ - hypothetical particles similar to tachyons that travel backward in time which may contact an observer's brain to produce a precognitive experience. The major problem with the tachyon theory of precognition is that tachyons have never been observed to exist; they remain theoretical constructs.

Psi-mediated instrumental response theory, offered by then psychologist Rex Stanford (1974) proposes that humans unconsciously and automatically scan their environment for motivationally relevant information, including - as the subliminal awareness models suggest - information that will only occur in the future of each conscious observer. This information will be used, by those who are so disposed, to place the person in a goal-relevant position with respect to its environment. This creates the experience of precognition, should some of this information have been represented in conscious imagery or other representational forms. One class of parapsychological theory – for example Schmidt (1984) and Walker (1984, 1987) makes reference to the measurement problem in quantum mechanics, particularly as it implicates the constructive role of human observation. Precognition, in the context of these theories, is generally conceived in the manner of retroactive psychokinesis, but without recourse to any notion of the transmission of psychophysical energy. According to some observational theories, it is at the point of observation of a future event that the event is, in fact, determined, and, under certain conditions of motivation, randomness and feedback, this future observation can inform the present observer. Another class of theories is based on the block universe model, in which future events already exist in spacetime, according to the special theory of relativity. The theories explain precognition as the retrieval of memories from the brain in the future, which could occur in a similar way to that in which ordinary memories are retrieved from the brain in the past – Marshall (1960) and Taylor (2007) for example. 

The theory proposed by Taylor is based on the work of David Bohm (1982) - the theory of the implicate order, which suggests that if similar structures are created at different places and different times, the structures resonate with a tendency to become more closely similar to one another. Taylor applies the principles to the neuronal spatiotemporal patterns that are activated in the brain, to show how an information transfer could be produced. For example, a precognition would occur when the pattern activated at the time of the future experience of an event resonates with any similar pattern that is spontaneously activated in the present. This might enable the present activation to be sustained until it produces the conscious awareness of an event similar to the one that will be experienced in the future.

Louisa Rhine at the Parapsychology Laboratory at Duke University compiled the best-known and largest body of dream evidence. Rhine (1969) collected over 7000 accounts of ESP experiences - the majority of these accounts were dream related and were seemingly precognitive in nature. The material for this work was collected by advertisements in various well-known popular media.

Ryback (1988) a psychologist in Atlanta, used a questionnaire survey approach to investigate precognitive dreaming in college students. His survey of over 433 participants showed that 290 or 66.9 percent reported some form of paranormal dream. He rejected many of these claims and reached a conclusion that 8.8 percent of the population was having actual precognitive dreams.

An early inquiry into this phenomenon was done by Aristotle in his On Divination in Sleep. His criticism of these claims appeals to the fact that ‘the sender of such dreams should be God" and "the fact that those to whom he sends them are not the best and wisest, but merely commonplace persons". Thus: "Most [so-called prophetic] dreams are, however, to be classed as mere coincidences..." Here, "coincidence" being defined by Aristotle as that which does not take "place according to a universal or general rule" and referring to things which are not of themselves by necessity causally connected. His example being taking a walk during an eclipse - neither the walk nor the eclipse being apparently causally connected and so only by ‘coincidence’ do they occur simultaneously. Other researchers in this area are more guarded in their reports on the value or use of dreams. In his book The Interpretation of Dreams (1900), Freud argued that the foundation of all dream content is the fulfillment of wishes, conscious or not and devoid of psychic content.  On the other hand, Freud's view of precognition evolved. According to Jung, Freud's ‘materialistic prejudice’ and ‘shallow positivism’ lead him to reject the entire complex of questions relating to precognition and the occult as ‘nonsensical’. But, according to Jung, years later, Freud both "recognized the seriousness of parapsychology and acknowledged the factuality of 'occult' phenomena". Dreams which appear to be precognitive may in fact be the result of the ‘Law of Large Numbers’. Robert Todd Carroll, author of The Skeptic's Dictionary explains it this way: "Say the odds are a million to one that when a person has a dream of an airplane crash, there is an airplane crash the next day. With 6 billion people having an average of 250 dream themes each per night, there should be about 1.5 million people a day who have dreams that seem clairvoyant."

The most extensive studies on precognition in dreams were carried out by the research group at the Maimonides Hospital, New York (Krippner et al, 1989). In these studies a ‘sender' attempted to send images to a ‘receiver' who slept in another room and whose sleep was recorded with standard EEG leads. When the sleeper entered REM he was awakened and reported whatever he was dreaming. Independent judges blind to the purpose and procedures of the experiment then took the dreams and judged if they contained any of the images sent by the sender. The experiments were monitored by independent observers and professional magicians to make sure that there was no possible leakage occurring between the experimenters, the sender or receiver. Subsequent analyses of hit rates yielded highly significant results. Dream images very frequently contained images sent by the sender. Further studies in other labs involved the dreamer attempting to dream about a target that would be randomly selected once he awoke. Once again hit rates were far beyond chance levels. Despite these exciting results some labs have failed to replicate the highly significant hit rates while other Labs have replicated the basic findings. Differences in replication may be due to many factors. Psi may not exist at all. Or it may be that you are much more likely to get significant hit rates if you use participants with high Psi abilities like the high stimulus seekers in the work of Bem (2011).

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