Anomalistic Psychology

Characteristics of pseudoscience:

• Not published in peer reivew journals but in magazines, newspapers, on the internet;
• Investigations are often methodologically flawed and not replicable;
• Specialist terms are used with no clearly operationalised definition;
• Theories are usually unfalsifiable;
• No obvious progress in the accumulation of knowledge;
• Evidence is not sound and arguments are based on emotion/intuition;
• Counter-evidence is usually dismissed without consideration;
• Practitioners often promote 'cures' without scientific research support.

Burden of proof is misplaced.

Variables are not clearly defined of operationalised.

No explanations are offered. 

Soal-Goldney (1941-43)

• Suggesting precognitive ability of a single participant.
• Were long regarded as some of the best in the field because they relied on independent checking and witnesses - prevent fraud.
• Participant was asked to guess cards.
• Hit rate was much above chance and highly significant. 
• Years later, statistical evidence uncovered that Dr. Soal had altered some of the raw data.

Walter J. Levy (1974)

• J. B. Rhine's successor as director of the Institute for Parapsychology.
• Levy reported on some successful ESP studies involving computer-controlled manipulation of non-human subjects (eggs and rats).
• His studies showed very high positive results.
• Because of the nature of his studies, he avoided criticisms regarding experimenter effects.
• Fellow researchers became suspicious.
• Levy had interfered with data-recording equipment and manually created fraudulent strings of positive results.
• Rhine fired Levy and reported the fraud in a number of articles. 

• Used to test for telepathy.
• Sender transmits mentally the identity of a randomly selected target to a receiver who is perceptually deprived. 
• Participants' eyes are covered with half ping-pong balls (visual field is blank) and wear headphones playing white or pink noise (audio field is blank).
• A red light is shone on the face of the receiver and will have the images sent to them.
• At pre-specified times, the 'sender' -in another room- attempts to transmit information about a randomly selected target.
• At the same time, the 'receiver' verbally describes their imagery.
• Afterwards, the receiver judges which of the possible images was being transmitted to them.
• Statistically, there is a 25% chance of achieving a hit.

Milton and Wiseman (1999)

• Published a meta-analysis of 30 ganzfeld studies carried out in 7 independent labs against strict guidelines. 
• Participants were found NOT to score above chance (25%) - scores weren't significant.

Cut off date for studies to be completed was Feb 1997. A large-scale study with positive results was therefore not included in the meta-analysis. If it had been included, the results of the meta-analysis would have been significant.

Honorton et al (1990)

• Reviewed 11 studies.
• Reported 34% hit rate - significant result. 

The conditions required to establish a reliably positive outcome in Ganzfeld studies have yet to be specified. 

• SHEEP = those who believe in ESP. GOATS = those who don't believe in ESP.
• Above average hit rate for sheep and below average for goats.
• Confounding variable - belief of the paranormal shapes our experiences of it. 
• Believers will try to encourage more detail about the image than non-believers and are more generous in deciding what constitutes a hit. 

Bem and Honorton (1994)

Suggested the following guidelines for conducting Ganzfeld experiments:

• Strict security against sensory leakage;
• Proper randomization of subjects;
• Statistical correction for multiple analysis;
• Advance specification of status of experiment;
• Full documentation of experimental procedures;
• Full description of statistical tests.

Introduction of Auto-Ganzfeld - reduced human bias and creates more valid, replicable studies. 

Avoids experimenter effects, bias, extraneous variables and reduces fraud.

PK - the ability to move an object by mental intention alone.

Split into two areas:

1. Macro PK - clearly observable effects (eg levitation of a chair);

2. Micro PK - weaker effects unnoticeable to the naked eye - require statistical evaluation (influencing the throw of a die) 

Now researched more than macro PK.

Methods of investigating PK

• J. B. Rhine investigated throwing dice when a participant would have to state the number that would be on the upward face BEFORE it landed. 
• The dice rolled automatically in a wire cage - reduce experimenter effects.
• Experiments continued to use the same regulations to eliminate bias from unbalanced dice. 
• Dice have been placed in cups to stop participants using special tricks to throw them.
• Have been placed in eletrically-driven rotating cages and have been photographed automatically to eliminate experimenter effects.

• Tests required the participants to will the fall of the dice with selected target faces showing.
• Numerous throws were made one after the other before another target was chosen.
• Result was positive - participans were able to correctly state the number at a higher rate than chance (effect was very weak). 
• Similar to ESP as it requires similar processes to ESP (no explanation of what these processes are).
• Standards: Having 2 researchers; true randomisation of targets; using independent recording of targets.
• Technology has allowed development of fully automated experiments studying potential interactions between mind and matter. 
• True random number generator (RNG) makes a data stream that is recorded and analysed by computer software.
• Subject tries to mentally change the distribution of random numbers - usually experimental design equivalent to getting more 'heads' than 'tails' while flipping a coin. 
• In the RNG study, design flexibility can be mixed with tight controls while collecting lots of data in a short period of time. 
• Has been used to test people for PK and test influence on RNGs of large groups of people.

Hansel (1989)

• Well-controlled trials produce no support for PK.
• 13/30 studies he examined produced positive results - none of these were well-controlled.
• Flawed methodology = positive findings. 

Radin and Nelson (2003)

• Reviewed 500 studies of micro-PK 1959-2000
• Found no significant relationship between methodological quality and outcome. 
• Suggests quality is not a factor in producing significant effects.

Bierman (2000)

• Analysed PK studies since J. B. Rhine and found effect size has been getting smaller. 
• Usually effect size gets bigger as scientists figure out what is happening and can control variables.
• Increasing control has opposite effect in paranormal research.
• Suggests phenomena are not real.

Disagreement over results:

• Some ESP meta-analyses have suggested significant results - others haven't. Shows problems of meta-analysis. 
• Decision as to what data should be included has a major effect on the results. 
• Evidence of Macro-PK has been largely discredited - effects been reproduced by conjourers showing how fraud and slight of hand can be used.
• Evidence of Micro-PK is stronger - meta-analysis has shown a variety of effects so no clear conclusion has yet been drawn.

Experimenter bias

• Shown to be common in parapsychology.
• A positive attitude towards the paranormal tends to be linked with positive results. This could be through:

Unconcious influences from the research either on participants or data collection;

Deliberate fraud or methodological flaws.

• Co-occurence of 2 or more events which happen at the same time which leads to bellief that these events are connected, when they're not.
• No obvious relationship between the two but a belief forms which creates a cognitive bias that one has caused the other.

Illusion of Causality

• People assume 2 events that co-occur are linked when they are just a coincidence. 
• They happen at the same time but one has not caused the other. 

AO2 Type 1 errors are adaptive - seeing an attacker that isn't there and being prepared but not needing to be is better than missing an attacker that is there and not being prepared. 

Foster and Koko

• Argue the adaptive advantage will persist as long as the occasionally correct response has an adaptive benefit.

When people make links between events, they feel they are more in control - make the world seem more orderly - reduces anxiety.

Whitson and Galinsky (2008)

• Showed people given a reduced sense of control were more likely to be superstitious. 
• Benefit - prepares us for unpredictable circumstances rather than withdrw from them.
• There is no real basis for superstition but it may help people to deal with challenges.
• Can also reduce anxiety.

Believers are less intelligent and therefore less able to accurately judge whether or not there is a causal link between things.

Wiseman and Watt (2006)

• Concluded syllogistic reasoning is what makes the difference between believers and non-believers - not general cognitive ability.
• Suggests that general cognitive ability may be too diverse to provide a good explanation.

New Scientist survey indicated that 67% of readers regarded ESP as a fact or a likely possibility - shows cognitive ability does not have a simple relationship with belief in the paranormal. (Readers of New Scientist should have higher cognitive abilities).

Brugger (2002)

• People with high levels of dopamine are more likely to find significance in coincidence.

• When non-believers were given L-dopa they had increased dopamine levels and were more likely to see faces that weren't there. 
• Shows that errors of judgement in terms of coincidence may be due to high levels of dopamine. 
• However, it's adaptive to see things that aren't there but miss some that are there.

• High dopamine levels are a feature of schizotypal characteristics - including magical thinking.
• Dopamine may be an important factor in paranormal/anomalous beliefs. 

The liklihood of an event occurring. Believers in the paranormal underestimate the probability of things occurring by chance. They reject coincidence as an explanation and attribute causality when events are random. 

Blackmore and Troscianko (1985)

• Asked participants questions including the birthday party paradox.
• More goats than sheep got the answer right.

Musch and Ehrenberg (2002)

• Controlled for differences in general cognitive ability.
• Found this reduced performance differences between believers and non-believers on probability judgemets to 0. 
• Indicates poor probability judgements are due to low cognitive ability.

Research suggests a link between probability misjudgement and paranormal beliefs - a link does not mean we are justified in concluding that difficulties in making appropriate probability judgements CAUSE paranormal beliefs. May be an intervening factor - cognitive factor. 

Personality - a collection of common characteristics.

Fantasy Proneness (FP)

• Tendency to become so deeply absorbed in a fantasy that it feels as if it is actually happening.
• More likely to believe in the paranormal and anomalous experiences. 

Wilson and Barber (1983)

• Compared 27 easily hypnotised vs. 26 not.
• Found easily hypnotised thought their toys had emotions, were more likely to be fantasy characters in play and were praised by adults for fantasy play.
• As adults - spend more time fantasising during the day, experience fantasies as more real and claim to have psychic abilities and experience apparitions.

Wiseman (2003)

• Held a mock seance. 
• Participants were aware it was fake but still believe the table had moved.
• Those who believed it were more likely to be believers as they were more deeply absorbed.

Outgoing and seek new experiences and more open to paranormal beliefs. Seek extra stimulation to increase brain arousal.

Peltzer (2002)

Found extraversion was associated with paranormal beliefs but neuroticism and psychoticism weren't. 

Honorton

• Meta-analysis of 60 studies.
• Found positive correlation between ESP performance and extraversion.
• Explanation: extraverts are more confident in new situations and are more open to paranormal experiences which increases their belief and the amount of information they give. 

Tendancy to experience negative emotional states. Often anxious, moody and emotionally unstable. Paranormal beliefs may create a distance from reality as a defence mechanism to reduce negative emotional states (anxiety).

Wiseman and Watt (2004)

• Questionnaires on neuroticism and paranormal belief.
• Found a strong correlation but only on beliefs relating to bad luck.
• Neuroticism does not explain all paranormal beliefs. 

Internal locus of control has been linked to superstitions.

External locus of control links to the belief that nothing is down to fate or good luck, but the person themself. 

• Complex relationship between personality factors and anomalous experience - different personality factors could be associated with different areas. 
• May be unable to study these things at the moment - not everyone has these abilities. 
• Personality is complex - 1 factor may be reductionist. 

Williams

• Correlation of +0.32 between neuroticism and paranormal belief - no correlation with extraversion.

Peltzer

• Found extraversion was link to paranormal beliefs but neuroticism wasn't. 

Shows further research is needed.

Question of validity in terms of method. 

• Correlations found between personality factors and paranormal beliefs depend largely on how personality factors are measured. 
• Wiseman and Watt found neuroticism was only related to beliefs relating to bad luck - not all paranormal beliefs. 
• Suggested previous research may lack validity because of the way it's been assessed. 

The subjective belief that a behaviour will have an effect on another area, either + or -. Often applied to areas surrounding luck, spirituality or prophecy.

Behavioural explanation (AO1)

• Superstitious behaviour is learned through operant conditioning.
• Accidental stimulus-response link is learned and maintained through negative reinforcement.
• When superstitious behaviour is performed, anxiety is reduced - superstitious behaviour is reinforced. 

AO2 POSITIVES

• Provides a reason why superstitions are so persistent. Enough of a link in mind so the behaviour is continued thinking it will affect the outcome. 
• Good theory in relation to humans.
• Matute - Study conducted in a library. Computer made a lot of noise and participants had to stop it by pressing lots of buttons. When the noise happened again, participants pressed the same button which stopped it the first time. Indicates the way humans learn and make associations and explains how superstitions form and supports behaviourist explanation.

• Skinner - Found certain random behaviours that preceded food pellets being released were reinforced. Pigeons connected their behaviour with the appearance of food so would repeat it with the food acting as reinforcement. Occasional appearance of food was enough to reinforce their behaviour and in a similar way to humans the times food doesn't appear do nt seem to have an effect on the belief. 

AO2 - NEGATIVES

• Is Skinner's explanation complete? Where is our reward for not walking under a ladder? If the behaviour isn't reinforced it should be extinguished.
• Staddon and Simmelhag (1997) - replicated Skinner and the pigeons. Found the same behaviour but the ritual behaviours performed by the pigeons were unrelated to the food reward. 'Accidental' learning of superstitions could be wrong. 

Evolutionary Explanation 

• Unjustified causal links that stem from making type one errors. 
• Causal thinking evolved because it allows people to understand and control their environment. 
• Eating something poisonous would be fatal if we couldn't make the link between the 2 things and kept doing it. 

• It's adaptive behaviour because it's better to see more links than are there than miss the ones that are there (false positive). 
• Better to be superstitious in survival terms and make links that don't exist rather than miss important ones. 

POSITIVES

• Support from superstition being common universally. 
• Culturally transmitted superstitions (Friday 13th).
• If causal thinking has evolved because its beneficial to us this has implications for understanding mental health.

NEGATIVES

• Criticise superstitions being 'adaptive' as they are often not posisitve and can mean taking part in lengthy rituals. 

When people feel they're not in control they carry out superstitious rituals to make themselves feel more in control.

Whitson and Galinksy (2008)

• Showed people given a reduced sense of control were more likely to be superstitious. 
• Benefit as it prepares us for unpredictable situations rather than withdraw from them. 
• No real basis for the superstition but it may help people deal with challenges and improve their self belief. 

Sense of control may be adaptive as it prevents anxiety about events that can't be changed.

May waste a lot of time on unnecessary behaviours or prevent someone from taking a more sensible course of action.

Clinical term to describe a variety of non-scientific and irrational beliefs. 

Generally centered around correlations between events and making a non-existent link between 2 things. 

Psychodynamic Explanation

• Freud (1913) indentified MT as childlike thought where children project their inner feelings on the outer world.
• When adults show this behaviour it's a defence mechanism - regress to a child-like state to cope with anxiety. 

Pronin (2006)

• Participants asked to stick pins in voodoo dolls felt more responsible for the supposed headache of a confederate if they saw their intended victim acting stupidly beforehand.
• Two events weren't related but participants awareness of the pin pushing led them to assume their thoughts had been the cause.
• Supports psychodynamic as participants thought they could influence someone else just by thought.

Things that have been in contact continue to act upon one another even after physical contact stops. 

Nemeroff and Rozin (1994)

• May be due to our evolved fear of germs and contagion. 
• Adaptive to avoid touching something that had been in contact with an ill person and this causes an intuition that psychological and physical properties can pass between people and objects.

Rozin (1986)

• People wouldn't drink from a glass marked Cyanide, even though they knew it was sugar.

• MT may lead people to deal with their environment more confidently as they expect good things to happen because of their thoughts and actions.
• Self-efficacy (belief in your own abilities). 
• Placebo effect - MT acts link a placebo creating a positive opinion and this accounts for improvements. 

Rosenthal and Jacobsen (1968)

• Showed children's IQ scores increased over a year as their teachers were lead to expect them to do better.
• Self-fulfilling prophecy - things turn out as we expect because of our expectation. 

• People who are depressed generally show less MT - depression realism.
• Suggests a fully accurate assessment of your own abilities may not be good for you - it's linked to depression.

Mohr et al (2005)

• Linked lack of MT to low levels of dopamine.

Dopamine is high in both schizophrenics and believers - link between neurochemistry, magical thinking and mental disorder. 

Costs of MT

MT is linked to mental disorders - too much is not a good thing. (Youlmaz et al (2011).

MT is a characteristic of schizotypal personality disorder and schizophrenia (Weinberger and Harrison (2011).

Both show MT can be linked with poor psychological health and negative outcomes. 

A type of relationship a living person says they have with spirits. Mediums tend to claim they can communicate with spirits and pass on messages to loved ones 'left behind'.

• Has a stereotypical image due to the media. 
• Features heavily in the USA but growing in popularity in the UK.

Sensitivity to cues

• Many clues to help a talented medium produce accurate information (cold reading).
• Even without seeing their 'sitter' they can pick up information from their tone of voice and replies to previous statements. 

The Barnum effect

• Cold reader starts with general statements which elicit responses from the sitter.
• Responses can be used in later conversation to convince listener of psychic abilities.
• Willingness of sitters to elaborate on information helps the medium to appear to have powers. 

Fraud

• People resort to complex and convincing strategies. 
• Mediums may hire an accomplice to visit a regular sitter. In the visit, the accomplice asks to use the toilet and can steal a treasured possession. Later, the medium asks if the person has lost something treasured and can tell them where to find it. 

Schwartz et al (2001)

• Tested 5 mediums.
• 2 women were sitters - both unknown to the mediums, were over 40 annd had experienced a number of recent deaths. 
• Mediums could not see the sitters and the sitters could only answer yes or no. 
• Sitters judged the accuracy of the mediums' statements as 83% and 77%.
• Group of undergraduates were shown the statements and a photograph of the sitter and asked to guess the answer. 
• 36% guessed correctly, suggesting medium's performance was well above chance with the original sitters. 

Rock and Beischel (2008)

• Tested belief that mediums can report accurate information about dead people without cues. 
• 2 conditions - 1: loved one is alive; 2: loved is dead - medium blind to conditions. 
• 6 mediums spoke on the phone to a sitter. 
• Given no information about the sitter or their loved ones except names and conversation was only about their loved one. 
• Mediums found significant differences in information retrieved from 2 conditions.

Explanations: Willingness to be decieved

• Roe (1996) reported many sitters are aware mediums are using general statements but remain convinced. 
• Supported by Wiseman et al's (2003) mock seance.
• Participants knew it was fake but believers had a tendency to be taken in by events. 

Research studies: Contradictory evidence

• O'Keefe and Wiseman (2005) arranged for 5 mediums to give readings for 5 sitters.
• Each sitter read all of the 25 readings given and rated the person relevance for each statement.
• Ratings were lowest for the statements written for them.
• Well-controlled study - showed no evidence of mediumship.

Research studies: Criticism

• Schwartz et al (2001) used undergraduates to determine accuracy of cold readings.
• Each considered how accurately each statements reflected their own feelings. 
• Statements were written for older women who had experienced recent deaths so likely that undergraduates would find the statements low in accuracy.

Research studies: The sheep-goat effect

• General quality of the research carried out on mediumship is poor.
• Most people are happy to believe in it without scientific proof so there is less motivation to conduct well-controlled research.
• The research that is carried out often shows usual patterns of positive findings from believes and negative findings from sceptics. 

Any method/treatments used to relieve health provlems by purely mental means.

Can be face to face, over the phone or remotely. Methods include faith healing and therapeutic touch (TT).

Therapeutic Touch (TT)

Explained by supporters in terms of the ability to detect a patient's aura without touching their body. Health is restored by re-aligning the patient's aura (energy field). 

Wirth (1990)

• Studied patients with wounds who were treated either with TT or nothing.
• Patients weren't aware of what treatment they were receiving - eliminates placebo effect.
• Patients treated with TT healed faster - suggests TT works.

Rosa et al (1998)

• Tested 21 TT practitioners.
• Each sat on one side of a screen and placed their hands through 2 holes in it. 
• On the other side the experimenter placed one of her hands about 4 inches abover the practitioners right or left hand. 
• TT practitioners should feel the energy feel of the hand.
• Only correct 44% of the time - less than chance. 
• Shows they couldn't accurately detect the person's hand. 

Placebo effect

• Success could be due to placebo. 
• Beliefs are based on the facts that some psychic healing cases are 'successful'.
• Success could be due to spontaneous or temporary recover - relapses aren't reported. 

The effects of prayer

• Cha et al (2001) looked at effect of prayer on infertile women.
• Researchers arranged for Christian strangers to pray for some of the women.
• As far as they knew, no one prayed for the other women and infertile women were 2x likely to get pregnant. 

• Lyvers et al (2006) suggest belief in psychic healing may explain some of its success.
• Belief creates positive expectations - acts like a placebo.

Lack of support for placebo effect .

• Benson et al (2006) studied patients recovering from heart surgery. 
• One group were control, other 2 were told prayers were being said for them - only 1 group had prayers said for them, other group were placebo group.
• Those who suffered more complications were those who had been prayed for - doesn't support explanation of the placebo effect. 

Rosa et al (1998)

• Criticism as it was created by a 9 year old girl - not so discredible as it was published in a reputable and peer reviewed journal.
• TT supporters claimed the study invalid as experimenter wasn't ill which might affect their aura. 

Long et al (1999)

• Replicated Rosa et al's study using normal people (not TT practitioners) and found when experimenter's hand was only 3 inches away the results were better than chance.
• Could be due to body heat. 
• Glickman and Graceley replicated the study eliminating body heat and found results at chance level - supports heat explanation.

Wirth (1990)

• Failed to replicate own research on wound healing. Researchers wanted to discuss with him but couldn't contact him
• Has been convicted of fraud with a 5 year prison sentence. 

Cha et al (2001)

• Conducted her study with Wirth and Cha has been accused of plagiarism in another journal.
• Study continues to be cited and taken as evidence for the power or prayer. 

Sensation of being awake and seeing your own body outside of your physical body. 

About 15 - 20% of people claim to have experienced an OOBE (Blackmore, 1982).

Paranormal explanation

• Suggests something beyond our current understanding is happening. 
• Only possible way to explain how you can physically leave your body is by seperating mind and body.

Biological explanation

• Suggests OOBEs are linked to sensory disturbance .
• Blackmore (1982) - suggests we normally view the world as if we were behind our eyes.
• When sensory input breaks down, brain tries to reconstruct what we're seeing using memory and imagination.
• Memory images are often birds eye views so the constructed image usually appears to be viewing oneself from above. 

Naturally-occurring OOBEs

• Green (1968) studied 400 personal accounts of OOBEs and clssed them as parasomatic (20%) or asomatic (no sense of another body).
• 25% of cases were associated with psychological stress; 12% occurred during sleep.

Artificially induced OOBEs

• Alvarado (1982) reviewed lab studies of induced OOBEs.
• Participants asked to identify target objects out of sight of their physical body.
• Miss Z read a 5-digit number from another room.
• Alvarado considered evidence was weak with some striking results. 

Biological Studies

• Blanke et al (2002) induced OOBEs accidentally by electrically stimulating the TPJ in an epileptic woman . 
• Led them to study neurologically normal subjects as well.
• Stimulation of TPJ using transcranial magnetic stimulation cause OOBEs where as stimulation of other areas didn't. 

Paranormal explanation

• Evidence does not support such explanations.
• Alvarado's review did not find evidence that the parasomatic body had physically moved out of the physical body. 
• Did acknowledge some exceptional cases - could be explained by suspect methodology: participant might have seen object prior to test. 

Biological explanation

• Suggests OOBEs are linked to sensory disturbance.
• Support for this from Blanke - activation of TPJ.
• Other research shows this area of the brain is involved in construction of the sense of body in space. 
• Ehrsson also provided support for link between sensory disturbance and OOBEs.

Artificial vs Natural OOBEs

• Difficult to study natural OOBEs as they are unpredictable - even if researcher was present, OOBE would cease as soon as it was reported. 
• Most research is on artificially-induced OOBEs in labs.
• Some researchers don't regard these as equivalent to naturally-occurring OOBEs.

Individual Differences

• OOBEs reported more often by individuals who believe in the paranormal.
• People who have OOBEs are more fantasy prone, score higher on hypnotisability and on dissociation.
• Characteristics go some way to explaining why such people have OOBEs. 
• No evidence to suggest people who have OOBEs are mentally ill - experiene may make them feel like they're losing their mind. 

Occur when a person is close to death and after fainting or in a stressful or threatening situation.

Psychological explanation

• Some people hold paranormal beliefs - leads them to interpret events in terms of paranormal explanations eg viewing NDEs as spiritual experiences. 

Biological explanation

• Endorphins are released at times of pain and stress - lead to feelings of euphoria and detachment. 
• More recent explanations suggest NDEs are related to hypoxia - may occur during cardiac arrest or fainting.
• Hypoxia might cause REM intrusions which create a mixed sleep/awake state that could disrupt integration of sensory information.
• Hypoxia created a flood of glutamate - causes neuronal death.
• As a defence, brain creates a protective blockade to prevent neuronal death - blockade is source of an NDE. 

Naturally occurring NDEs

• Ring (1980) interviewed 100 people who had NDEs.
• Found 60% of survivors reported sense of peace; 33% reported OOBEs; 25% entered a tunnel; few experienced life review. 
• Nelson et al (2006) studied 55 people with NDEs and 55 controls. 
• Found NDE group were more likely to experience REM intrusions.
• Indicates having an NDE may be linked to dream micro sleep episodes while awake. 

Artificially induced NDEs

• Jansen (1993) experimented with ketamine, giving it to patients to observe the effects. 
• Found it produces classic symptoms of NDEs.
• Ketamine been found to trigger the same blockade as glutamate.
• Indicates blockade made by the brain to protect itself may be cause of NDE.

Psychological Explanation

• Fact NDEs aren't experienced by all near-death patients means there is likely to be a psychological component. 
• Some people may expect to have such experiences and then, if they experience certain physiological changes, they label these as spiritual.

Spiritual Explanation

• Van Lommel et al (2001) followed 344 cardiac survivors over 8 years.
• Found those who experienced NDE regarded it as a life-changing, spiritual experience. 
• Those who didn't continued to fear death. 
• Suggests it is often a spiritual experience but doesn't mean it's caused by spiritual factors. 

Cultural Differences

• Augustine (2008) presented a review of NDEs in different cultures - Indian NDEs involve encounters with Hindu figures. 
• Differences and similarities suggest both physiological and psychological factors are involved. 

Early studies may lack appropriate conrols. 

Interviewer bias may have affected data collected. Moody (1975) reported NDEs as wonderful experiences - more recent research found they are frightening for many people.

Reductionism

• Parnia suggests if it can be shown that mental experiences occu when the brain is inactive in an NDE - this might count as demonstration of the soul - mind seperate from the physical body. 
• Jansen (1993) says real reductionism comes from those who attempt to 'draw a mystical cover over the NDE, belittling the substantial evidence in favour of a scientific explanation'.