The Ganzfeld reviewed

With this post, I can begin a new series. The topic will be the infamous Ganzfeld experiments.
The story is long and there are many angles to it. First I will start with a quick overview of what the Ganzfeld is anyways and what the history is. That’s well trodden ground but the series would be incomplete without these basics.
Next, I will review the experimental design and what conclusions can be drawn from positive results. That is an often neglected topic.
After that, I will review the debate so far in some depth. That will be several parts, I don’t know how many exactly yet.
At some point I will do some analyzing of the data myself, to break out of the tedious he said/she said mode.

Now let’s begin with the quick overview.

What is the Ganzfeld?

The Ganzfeld is a way of inducing mild and benign hallucinations. The word is German and means “whole field”. This refers to the whole field of vision being taken up by a uniform stimulus.
In practice one halves a table tennis ball and puts one half over each eye. Then a (usually red) light is shone on the participants face. He or she now sees only a uniform red glow and after a while will begin seeing things.
The effect can also be elicited in different ways, for example, by staring at a white wall. Additionally, parapsychologists usually have their test subjects wear headphones playing white or pink noise.

It is thought that the hallucinations result from the way the nervous system tries to deal with the lack of sense data. It “turns up the gain” in an attempt to get some usable signal but ends up with only noise. The hallucinations are the equivalent of the hissing that results when cheap speakers have the volume turned to max.

What is a Ganzfeld Experiment in parapsychology?

Parapsychologists in the early 1970ies had the idea that we are constantly, somehow receiving ESP impressions but that these are usually crowded out by the perceptions coming from the known senses. They reasoned that if the known senses were shut down and everything else amplified, then this should allow the ever present ESP to come to the fore.
However, in the almost 40 years since, there has been very little effort to actually test this hypothesis. In fact, it seems to have taken over a quarter century before anyone even asked the question. I would have expected that one would first test if the Ganzfeld technique can boost ESP perception. If it can I would expect it to be used as an add-on in most parapsychological experiments. The more ESP perception you can produce, the more data you have to study, right?

It has not happened like that, though. Instead a specific type of experiment was created. The typical Ganzfeld Experiment purports to be a test of telepathy. It involves two subjects, one called “sender” the other “receiver”. The “sender” is presented with a “target”, typically a photo or video clip, while the “receiver”, in another room, is in a Ganzfeld state and simply speaks his impressions.
The task then is to identify the “target”, using these impressions. This may be done by the subject alone, by a third person or by the subject with the aid of a third person.
There are usually 3 “decoys” along with which the “target” is presented. This means that, theoretically, there should be a 1 in 4 chance of guessing right just by chance.

The claim is that subjects in Ganzfeld Experiments guess correct about 1 in 3 times rather than the expected 1 in 4 times. This then is supposed to be evidence for telepathy. Whether it is, I will examine in detail in another post. For now I will just point out the obvious. One cannot conclude from such experiments if the Ganzfeld actually does anything, consideration of ESP aside.

A brief history

The parapsychological Ganzfeld experiment was pioneered by Charles Honorton who, together with Sharon Harper, published the first account of one in 1974. In the following years more experiments were conducted and published. The supposed success of this method prompted Ray Hyman, a mainstream psychologist with a long-standing interest in parapsychology, to analyze the results. He argued that they were best explained by a number of flaws in the set-up. Honorton disputed this and a lengthy debate ensued.
Eventually, in 1986, during a lunch to which they both had been invited, they discovered that besides their disagreements they also agreed on many things. Instead of continuing the debate they co-authored an article agreeing that only further experiments could bring clarity and also outlining certain procedural musts to avoid any possibility of error. Honorton then went on to realize experiments following these guidelines. The quality of his work convinced mainstream psychologist Daryl Bem. With his help the results of the new experiments were published in a respectable psychology journal in 1994.

If this was a Hollywood movie it would end here, with the triumph of the underdog.

Science does not end, however. These high quality experiments took place all in one lab, independent confirmation was still required. Besides, as Hyman pointed out, parapsychology had been at this point before only to see seemingly solid evidence implode.
In 1998 then another analysis came out, this one by Milton and Wiseman. It looked at all the smaller experiments that had come out following the publication of the guidelines in order to see if they had done as well as Honorton’s lab.
This turned out not to be the case. Independent confirmation had failed.

This would be another place for a movie to end. The good guys come riding into town and set people straight on the nonsense the snake oil salesman is peddling.

But again life does not offer neat endings. Parapsychologists were quick to explain away this failure, although not with arguments that could convince mainstream thinkers.
Meanwhile Ganzfeld work continued. In 2010 another analysis came out purporting to show that there is something there after all.

And that concludes the brief history. It has a lot of holes and leaves much unsaid. The details will be found in the posts to come.