extrasensory perception (esp) lecture 7 parapsychology paul staples
TRANSCRIPT
Extrasensory Perception (ESP)
Lecture 7ParapsychologyPaul Staples
Overview
What is ESP? Telepathy Clairvoyance Precognition and Retrocognition
Experimental evidence Restricted-choice experiments Free-response experiments
The process approach Summary
Learning Objectives
This session will enable you to Give a reasonable definition of ESP Categorise the various types of ESP Understand the nature of the experimental evidence
available Appreciate the criticisms and counter-criticisms of
some of the findings Appreciate the difference between resticted-choice
and free-response scenarios Recognise that there are other considerations, such as
those suggested by the process approach
What is ESP?
Extrasensory perception (ESP) is perception that occurs independently of the main physical senses (sight, hearing, touch, taste and smell or, indeed, perceptual processes such as proprioception)
In some ways the term is vague but it is generally used to imply a source of information that is unknown to modern science
ESP can be divided into a number of sub-categories
Telepathy
For telepathy the source of information is another person’s mind
The principle requirement of telepathic transmission is that the information transfer cannot be explained by any known physical process
Often the demonstration involves information transfer over large distances
Unlike physical information transfer, telepathy is not subject to the weakening of the signal the further you move away from the source
Clairvoyance
Clairvoyance is similar to telepathy except that the source of the information is an object or event rather than another mind
As well as clairvoyance, we can propose clairaudience where the source of information is auditory rather than visual
Clairaudience is an alleged psychic ability to hear things that are beyond the range of the ordinary power of hearing, such as voices or messages from the dead
Precognition and retrocognition
If the clairvoyance or clairaudience concerns things in the future or the past the these are referred to as precognition and retrocognition respectively
Dreams have sometimes been related to precognition and characters like Nostradamus are famous for their precognitive visions
Retrocognitions can be about recent events (e.g. the perpetrator of a recent murder) or distant events (e.g. historic events)
Retrocognition is different from past life regression
Experimental evidence
ESP experiments fall into two broad categories Restricted-choice experiments
The receiver must make a decision about what is being transmitted from a small set of known possibilities
Zener cards are an example of restricted choice stimuli Free-response experiments
Here the sender will choose an item from a large but finite set of possible stimuli
The receiver is not told anything about the nature of the chosen stimulus
The remote viewing you participated in was a free-response set up.
Restricted-choice experiments
In the 1930s one of the most prominent places for ESP research was the Rhine laboratory in America established by J B Rhine
A typical study from that era is the Pearce-Pratt experiment
Typical card-guessing experiment – using zener decks (25 cards, 5 target alternatives, MCE = 5)
74 runs conducted over 37 sessions Sender and receiver (Pratt and Pearce) in
separate buildings (100 or 250 yards apart)
Restricted-choice experiments
Watches synchronised so that when Pratt turned over a card, Pearce made a guess
Both recorded their sequences Hits counted independently by Rhine Rhine present with Pratt during last few
sessions Mean hits per run was significant at p < 10-22
No likelihood that results were due to chance
Restricted-choice experiments
Hansel (1961) criticised the study by suggesting that as no-one was with Pearce during the sessions, he could have gone out of his room and looked through a window at Pratt’s cards.
This could not be shown to be wrong until 1967 when Stevenson was able to locate the original blueprints
However, on scrutinising the official and unofficial reports of the experiments there are inconsistencies in the number of hits recorded
Restricted-choice experiments
Pratt-Woodruff experiment (1939) 2,400 runs across 32 volunteers Mean hit rate was 5.21, p < 0.00001 However, the result attributable to only 5 of the 32
volunteers Pavel Stepanek
Library clerk from Czechoslovakia Took part in 27 studies across 18 investigators Was discovered through his ability to state whether
the white or dark side of a thin piece of cardboard was face up inside an opaque envelope
Performance level at around 57% correct, p<10-6
Restricted-choice experiments
Bill Delmore Yale law student in the early 1970s Unusual in that he had vivid visual imagery, frequent lucid
dreams (knowing you are dreaming) and a high degree of confidence in his psi abilities
520 playing cards mixed and placed in desk drawers Experimenter picked a card and without looking at it placed it
in an opaque folder 46 runs of 52 trials each (2392 trials) Delmore had an excess of exact hits! For exact hits p < 10-30
Delmore was also successful on other tasks
Free-response experiments
Remote viewing (RV) experiments Puthoff and Targ were the first to do this in the late 1970s They worked with Uri Geller whom most parapsychologists
quickly became suspicious of Their first work was with Pat Price, a Californian police
commissioner Target location chosen from a pool of 100 Target observed for 30 minutes Price asked to verbally describe and to draw the location Nine trials Independent judge taken to each site and then asked to rank
the drawings from 1 to 9 according to their similarity to the site Seven were ranked first at the correct site (p < 10-4)
Free-response experiments
Critics of these experiments are Marks and Kammann (1980)
They suggested that there were biasing clues in the transcripts of the verbal descriptions
Now some of the judges failed to correctly identify matches
Also, only the most successful trials were chosen for publication and this falsely increased the statistical result
However, there have been a number of successful RV experiments reported in the literature
Free-response experiments
Ganzfeld Experiments We have already talked about the Ganzfeld
procedure It has become a popular method of testing ESP Honorton (1978) claimed that 23 out of 42 ganzfeld
experiments had yielded statistically significant results
Successful results came from 9 independent labs Taken as a collection of results the evidence seems
quite impressive
Free-response experiments
In the 1980s, Hyman criticised the findings on several grounds
Experiments had small numbers of participants and may only have been submitted for publication if the data were significant
Scoring procedures varied widely across the studies In experiments using multiple conditions only one had
to be successful for a positive claim to be made One-tailed tests were used even though psi-missing
outcomes (the other tail) were considered as successes (i.e. a success was recorded for a score significantly different from chance whether it be better or worse than chance)
Free-response experiments
Honorton countered these criticisms by recalculating the results in line with the criticisms
The level of success was not compromised even though the success rates reported had been too high
Other criticisms, such as one concerning the quality of the randomisation process, were conceded by Honorton
Free-response experiments
Overall, it would seem that the studies have been fairly rigorous even though improvements could have been made
However, this is no more true here than it is in all other areas of human research
Whilst the apparent ESP demonstrated so far may not compel one to accept ESP, the evidence does point to there being something worth further investigation
The process approach
All of the research considered so far is concerned with trying to establish proof of the existence of ESP
Other research tries to increase our understanding of psi anomalies
Some may consider this approach premature until the proof has been verified
The process approach
The process approach looks at the following aspects that need to be considered Cognitive processes – right hemisphere, cognitive capacity. Belief in ESP – sheep and goats Personality traits – extraversion/ESP correlation The experimenter effect – experimenters get significant
results in psi experiments because of…experimenter error, psychology and psi hypotheses.
It attempts to explore the degree to which these factors interact with ESP
There is not time to explore these aspects further here
Summary
We have seen that there is some convincing data concerning the possible existence of ESP
The data are not yet at the stage where they provide unequivocal proof of the existence of ESP