Discuss controversies related to Ganzfeld studies if ESP and studies of psycho-kinesis

A Ganzfeld ("total field") experiments technique used in the field of parapsychology (a discipline that seeks to investigate the existence and causes of psychic abilities, near-death experiences, and life after death using the scientific method) to test individuals for extrasensory perception (ESP).

Before looking at the criticisms of the ganzfeld experiments, let's first examine the general design of the experiments done in 1974-1981. Not all experiments were conducted in the same

way.In a typical Ganzfeld experiment, a "receiver" is placed in a room relaxing in a comfortable chair with halved ping-pong balls over the eyes, having a red light shone on them. The receiver also wears a set of headphones through which white or pink noise (static) is played. The receiver is in this state of mild sensory deprivation for half an hour. During this time, a "sender" observes a randomly chosen target and tries to mentally send this information to the receiver. The receiver speaks out loud during the thirty minutes, describing what he or she can see. This is recorded by the experimenter (who is blind to the target) either by recording onto tape or by taking notes, and is used to help the receiver during the judging procedure.

In the judging procedure, the receiver is taken out of the Ganzfeld state and given a set of possible targets, from which they must decide which one most resembled the images they witnessed. Most commonly there are three decoys along with a copy of the target itself, giving an expected overall hit rate of 25% over several dozens of trials.

As mentioned above, there were problems with the original ganzfeld experiments involving sensory leakage and randomization procedures. There were other problems, as well. Only fifteen of the studies appeared in refereed journals; twenty were abstracts of papers delivered at meetings of the Parapsychological Association; 5 were published monographs; and two were undergraduate honors theses in biology. In 1981 or 1982, Honorton sent all the reported studies to Hyman who proceeded to do a meta-analysis of them. Hyman concluded that the data did not warrant belief in psi, primarily because of many flaws he found in the experiments themselves. He found three types of flaws: (1) security flaws (sensory leakage; information could have been transferred by experimenters to receivers by talking in the hallway or inadvertently communicating information during the judging phase); (2) statistical flaws; and (3) procedural flaws (randomization problems; documentation problems). He rejected twenty studies as being fatally flawed. That amounted to about half the database. He stripped the data down to twenty-two studies by eight investigators and 746 trials, which accounted for 48% of the data base. Even so, Hyman found the same hit rate of 38% for these studies that Honorton had found. But, after adjusting for selection bias and quality of study, Hyman calculated the replication success rate was 31% not 55%. In his view, 58% of the studies used inadequate randomization procedures. Honorton didn't

1Daljit Gill

agree with all of Hyman's criticisms—especially the ones claiming that there were statistical flaws in Honorton's meta-analysis—but he did agree that there were sufficient problems with the database that no grand conclusions should be drawn until further studies were done, studies that were very tightly designed and controlled.

In 1979, Susan Blackmore visited the laboratories of Carl Sargent in Cambridge. She noticed a number of irregularities in the procedure and wrote about them for the Journal of the Society for Psychical Research. It now appeared that on one session — number 9 — the following events had taken place:

1. Sargent did the randomization when he should not have. 2. A 'B' went missing from the drawer during the session, instead of

afterwards. 3. Sargent came into the judging and 'pushed' the subject towards 'B'. 4. An error of addition was made in favour of 'B' and 'B' was chosen. 5. 'B' was the target and the session a direct hit.

This article, along with further criticisms of Sargent's work from Adrian Parker and Nils Wiklund remained unpublished until 1987 but were well known in parapsychological circles. Sargent wrote a rebuttal to these criticisms (also not published until 1987) in which he did not deny that what Blackmore saw occurred, but her conclusions based on those observations were wrong and prejudiced. His co-workers also responded, saying that any deviation from protocol was the result of “random errors” rather than any concerted attempt at fraud. Sargent stopped working in parapsychology after this and did not respond "in a timely fashion" when the Council of the Parapsychological Association asked for his data and so his membership in that organization was allowed to lapse.

2Daljit Gill