Dean Radin, Parapsychology, and Science

It seems to me that people who want to believe in something tend to hastily jump to conclusions when presented with a bare minimum of evidence that seems to support the belief. Believers of ESP seem to like throwing Dean Radin's name around, for example. Radin has written some books (which I admittedly have not read), and is involved in parapsychology, including some experiments that purportedly prove the existence of a type of ESP.

The experiments certainly are intriguing--they essentially involve recording a test subject's response to certain stimuli (pictures, for example) that are intended to either provoke an emotional response or a non-emotional response. In Radin's experiment, it involved serene pictures (landscapes, trees, etc.) versus erotic or violent images (at a 2 to 1 ratio). Radin claims that the results of the experiments seem to show that the test subject responded to the emotional pictures before they were shown (he coins the term "presponse" to describe the effect).

A detailed explanation of some of these experiments can be found here. Note that even Radin himself confesses that the results of his experiments could have possible non-paranormal explanations:

The major (and maybe only) source of normal explanations remaining after Radin's original analyses is the hypothesis that subjects developed anticipatory strategies that resulted in different anticipatory physiology preceding calm or emotional pictures.

The idea is that the test subject's emotional "presponse" was subject to what is known as the gambler's fallacy. Essentially, after each calm picture, the subject would (incorrectly) assess the probability that the next picture would be an emotional one as slightly higher (thus increasing the measures of their emotional response). Additionally, after each emotional picture they would relax, figuring (also incorrectly) that they're not due for another one right away. The net result of this process would seemingly be that there would be an overall higher measure of emotional response prior to the emotional pictures than to the calm ones. This would explain the results of the experiment without resorting to the paranormal.

Radin dismisses this possibility due to a number of factors. Namely (a) that his results seem to show different levels of presentiment before erotic versus violent emotional pictures, which could not be explained by a simple anticipatory build-up; also, (b) further analysis of the data in which presentiment was measured at equal intervals before calm versus emotional images (for example, a calm image presented after two preceding calm images versus an emotional image presented after two calm images) showed that presentiment levels were higher before the emotional image than before the calm image, which would also not be expected assuming an anticipatory build-up explanation; finally, (c) he developed some computer simulations to test the anticipatory build-up models, and concluded that although there was an effect shown by his models, they were not to the same extent as found in the experiment (and thus his experimental results must require a paranormal effect to completely explain them).

Now, I am by no means an expert in statistics, or even experimental science. These are just some ideas that strike me as a skeptical layperson when reading about his reasons for dismissing an anticipatory effect.

(a) I can conceive of a situation, even under an anticipatory model, that would allow for apparent statistical differences in emotional measures before erotic and violent images. While the two types of images may certainly generate emotional responses in a subject, they both won't necessarily have the same "resetting" effect on the subject's anticipatory level. Conceivably, a subject's emotional response to erotic images may be a positive one, compared to a negative one for violent images. In other words, there may be a complex interaction of independent anticipation levels for each type of image.

(b) Admittedly, an explanation for the further statistical analysis mentioned above escapes me, other than it also possibly being due to what I said about (a). Unfortunately I don't have the mathematical training required in order to assess these claims one way or another.

(c) The computer models seem the most frivolous method of rationalization to me. This is an area in which I do have some small degree of expertise (B.Sc. in computer science from the University of Calgary). The models used are described in the link I provided above as such:

The following anticipatory strategies were tested:

a) Increase anticipation by 1 unit after each calm target, and reset anticipation to 1 after each emotional target.

b) Double the anticipation after each calm target (to a maximum of 500) and reset the anticipation after each emotional target to either half of the previous value, or 1.

The simulated effects in the open-deck situation were never larger than 2% while the observed experimental effects in Studies 1 and 2 were generally larger than 10%. However, these analyses are by no means exhaustive and there may be less plausible statistical anticipation models that may result in larger differences. The major point in favor of the psi hypothesis is that there are no indications in the real data that support any of these sequential strategy models.

No explanation for choosing these particular models is given, and it all seems highly arbitrary to me. The idea that a human brain and emotions can even remotely be modeled by these simple algorithms seems ridiculous--I could easily replicate either algorithm in 5-10 lines of computer code. It may very well be true that such models do not result in effects that are equal in magnitude as those shown in the experiment, but all that really says is that if there is a mundane anticipatory-effect that can explain the experimental results, that it is not governed by one of these two over-simplified algorithms. That's not really saying much when you consider the complexity of the human mind.

After a little more searching, I found a paper titled A Computational Expectation Bias as Revealed by Simulations of Presentiment Experiments (pdf), by Jan Dalkvista, Joakim Westerlunda and Dick J. Bierman. Interestingly, Bierman is one of the people who had originally replicated Radin's results in an independent experiment of a similar design (and is, in fact, the subject of the link I reference above regarding the experiment). This is pure speculation, but perhaps Bierman was not content in making the radical conclusions that Radin did, and instead went on to consider other possible explanations. The paper discusses the expectational bias, or anticipation build-up idea in much further depth, including more computer simulations that make Radin's dismissal of the effect seem a little hasty and premature. To quote the discussion from the end of the paper:

There is no doubt that the presentiment experiment could be afflicted by a potential statistical bias, based on an expectation effect: an effect of the expectation that the likelihood of an activating stimulus being presented increases with the number of previous consecutive calm stimuli – that is, a variant of the ”gambler's fallacy”.

Ultimately, given what information I have managed to gather, I remain highly skeptical of Radin's experiments and others modeled after them which replicate their results. I am not convinced that they inarguably represent a paranormal presentiment effect, and feel that the only reasonable conclusion to draw is that further study and experimentation should be performed. Fortunately, I am not alone in this, and other scientists have tried to further replicate the "presponse" phenomenon.

In a paper titled Exploring the Reliability of the "Presentiment" Effect (pdf), Richard S. Broughton details his attempt to replicate Radin's experiment. His design was similar, but the results failed to replicate the prior experiment. To quote the abstract:

The experiment did not produce overall evidence of a presentiment effect, nor did it demonstrate test-retest reliability. Since this experiment deviated from prior methods of analysis the data were examined without de-trending and automatic artifact removal, but there was still no evidence of a presentiment effect.

So, even using Radin's original statistical analysis methods, a similar experiment failed to show the same results. The possible reasons for this are discussed in the paper, but ultimately all it does for me is cast doubt on the original experiments. Add this to the innumerable additional scientific ESP experiments that have been performed over the years which decidedly fail to show any anomalous results, and it all further fuels my skepticism.

To add to the flames, I'll close this post with a couple links that I find particularly enlightening as to the state of parapsychology as a whole. The first is an entry in ex-parapsychologist Louie Savva's blog entitled Why I Quit Parapsychology. A short quote:

Evaluating parapsychology as a whole, it seems best described as a house of cards and one whose very foundations are extremely shaky and yet people continue to build on top, regardless.

Savva followed in the footsteps of Susan Blackmore, who also left the world of parapsychology in frustration. A quote from her website:

It was just over thirty years ago that I had the dramatic out-of-body experience that convinced me of the reality of psychic phenomena and launched me on a crusade to show those closed-minded scientists that consciousness could reach beyond the body and that death was not the end. Just a few years of careful experiments changed all that. I found no psychic phenomena - only wishful thinking, self-deception, experimental error and, occasionally, fraud. I became a sceptic.