Re-examining the ganzfeld

Today's post asks a question not because I'm trying to lead you toward a particular answer, but because I honestly don't know the answer myself.

In Wednesday's post, I discussed some alleged claims by psychics (which a team in Australia evaluated for accuracy and found seriously wanting) and made the statement, "I'm all for keeping an open mind about things, but at some point you have to conclude that a complete absence of hard evidence means there's nothing there to see."

A friend of mine responded, "What if there's hard evidence out there that you're choosing not to accept because you've already made your mind up?"  He wasn't being combative; like me, he was just asking a question, and it's actually a reasonable thing to ask.  And he sent me a link to a post over at Paranormal Daily News that looks at one of the most famous experimental setups for detecting psychic powers: the ganzfeld experiment.

"Ganzfeld" is German for "complete field," and refers to the fact that the test subjects are placed in near-complete sensory deprivation, in order to keep them from receiving any information accept (allegedly) from telepathy.  Padded goggles are placed over the eyes; earpieces play recordings of white noise.  The subjects lie flat in a place with no drafts or other air movement.  (Some have even had subjects floating in a sensory deprivation tank.)  Then the "sender" -- usually the researcher conducting the experiment -- looks at some kind of pattern, often the famous "Zener cards" (cards with five different geometric patterns in five different colors), and the "receiver" (the test subject) reports what (s)he sees/experiences.

A participant in a ganzfeld experiment [Image is in the Public Domain]

The Wikipedia page for the ganzfeld experiment (linked above) is unequivocal; it says, "[It] is a pseudoscientific technique to detect parapsychological phenomena...  Consistent, independent replication of ganzfeld experiments has not been achieved."  However, the article my friend sent is equally unequivocal in the opposite direction -- that it has generated results that are far outside of what would come out of a random-choice statistical model, and has been done over and over with the same outcome.  The author, Craig Weiler, writes:

This works.  Not perfectly, but certainly well enough for an experiment.  It’s been done more than enough times by more than enough people to rule out any statistical anomalies.  The success rate is typically between 32 and 35%.  That’s pretty normal for a successful, statistics based experiment.  There have been six different meta analyses from skeptics and researchers alike, all showing positive results.  From an objective scientific perspective, this is an ordinary successful scientific experiment.

While I can't say I warm to the sneery tone of the article -- Weiler really needs to learn the difference between a "skeptic" and a "scoffer" -- it does bring up the question of who's right, here.  The critics of the ganzfeld experiment and other such attempts to prove the existence of paranormal abilities claim that no sufficiently-controlled experiment has ever generated positive results; the supporters claim that there are plenty of positive results that all the scientists are ignoring because they can't explain them (or, worse, because those results contradict their own biases).

Weiler is right that there have been meta-analyses done of the ganzfeld results, and that they have changed the minds of neither the pro- nor the anti- factions.  Finding a truly unbiased analysis has turned out to be not to be easy.  A September 2020 article in Frontiers in Psychology by Thomas Rayberon comes the closest of anything I've seen, but unfortunately tries to steer a middle course of "maybe, maybe not" by agreeing with both sides at once even though they're saying opposite things.  Rayberon writes (citations have been removed in the interest of space; go to the original article if you're interested in seeing them):

Psi research can be considered as a subfield of consciousness studies concerned with interactions between individuals and their environment that transcends the ordinary constraints of space-time.  Different lines of research have been developed for more than a century to tackle psi using experimental research, spontaneous cases, clinical cases, selected participants, and applications.  Several meta-analyses of studies conducted under controlled conditions examine precognitive dreams, telepathy, and presentiment and have demonstrated statistically significant effects...

While these results support the existence of consistent anomalous experience/behavior that has been labeled “psi,” there is currently no consensus in the scientific community concerning their interpretation and two main positions have emerged so far.  The “skeptics” suppose that they are the consequences of errors, bias, and different forms of QRPs [questionable research practices].  The “proponents” argue that these results prove the existence of psi beyond reasonable doubt and that new research should move on to the analysis of psi processes rather than yet more attempts to prove its existence.  This absence of consensus is related to the difficulty of drawing firm conclusions from the results of psi research.  Indeed, they represent an anomaly because there is currently no scientific model – based on physical or biology principles – to explain such interactions even if they exist.

Which reminds me from the quote from Lord of the Rings, "Go not to the Elves for advice, for they will say both yes and no."  The last bit -- that there is no current scientific model that could account for psychic phenomena -- is certainly true; but if there are statistically significant effects (which Rayberon says explicitly in the preceding paragraph), then surely there must be some protocol for devising an experiment that meets the minimum criteria of the true skeptics (people who base their understanding on the evidence, regardless of what their preconceived notions might have said).  The fact that there is no current scientific model to explain telepathy is, while correct, entirely irrelevant.  The first thing to do is to determine if the phenomenon itself is real.  There was no scientific model to explain radioactivity when it was discovered by Henri Becquerel, nor the apparent constancy of the speed of light when it was demonstrated by Michelson and Morley, nor the patterns of inheritance uncovered by Gregor Mendel.  The first thing was to determine if what they were seeing was accurate.  Once that happened, the scientists moved on to trying to figure out a model that accounted for it.

Rayberon then goes on to make quite a puzzling statement that implies it might be impossible even to tell if the phenomenon is real.  Science, he says (again, correct most of the time) uses experimental protocols that eliminate any possibility of interference by the experimenter.  That's impossible in psi research (italics are the author's):

Thus, if psi exists, the problem is the following: an advertent or inadvertent “direct” interaction between the researcher and the object of study could be possible.  This destroys the conditions necessary for the convincing scientific demonstration of psi itself.

Rayberon says this "paradox" makes psi research impossible to confirm or disconfirm.  But isn't an interaction between the researcher and the test subject what the psi researchers themselves are trying to demonstrate?  What an honest psi researcher -- well, any honest researcher, really -- needs to do is to isolate the variable (s)he's studying so that, as far as is possible, whatever results come out of the experiment can only be attributable to that variable.  So in a properly-conducted ganzfeld experiment, the researcher has eliminated any possibility of the test subject getting information about the pattern from anywhere except the mind of the "sender."

And from my admittedly layperson's viewpoint, that can't be all that hard to do.  If there have been multiple instances of positive, statistically-significant results from ganzfeld trials -- and Weiler and Rayberon agree that there have been -- then they deserve some explanation other than shrugging and saying, "I don't see how it could work."  If there are "errors, biases, and questionable research practices" generating the results, the "skeptics" (using the word in the sense both Weiler and Rayberon use) need to determine what those are.  If, on the other hand, the results aren't from poor experimental design or outright cheating, then let's have the "skeptics" and "proponents" team up to find a protocol they can both agree to.

Figuring out a model for what's going on can wait until we see if there is anything going on.

So after accusing Rayberon of playing both sides, I'm honestly not doing much better.  My inclination is to doubt the existence of psi abilities because the evidence seems sketchy for such a wild claim.  But that inclination is a bias I'm well aware of, and all it would take is one sufficiently well-designed experiment to convince me I was wrong.  Right now, all that seems to be happening is both sides becoming more entrenched and yelling at each other across no-man's land, which doesn't accomplish much but pissing everyone off.

So come on, folks.  Either psi exists or it doesn't.  If it doesn't, we can go on to studying actual real phenomena.  If it does, it will overturn pretty much everything we know about psychology, and would be one of the most colossal discoveries in the past hundred years.  How about teaming up and settling this question once and for all?

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Contention in the ganzfeld

I just ran into an article over at Psychology Today that I thought deserved a close examination.

It's by Steve Taylor, senior lecturer in psychology at Leeds Beckett University, and is called "Open-Minded Science."  A one-line summary of the article is that science has an inherent bias against considering parapsychological phenomenon, and that there is compelling evidence of telepathy (known as "psi" by aficionados) from what is known as the ganzfeld experiment.

So, a little background.  Ganzfeld is a German word meaning "entire field," and purports to set test subjects up to maximize their ability to collect data from another mind telepathically.  First proposed by German psychology researcher Wolfgang Metzger, what the procedure entails is placing the subject in complete (or as complete as can be managed) sensory deprivation.  A series of patterns or letters, either on cards or on a computer screen, is observed by the researcher, and the subject attempts to identify what the researcher is seeing.  The removal of other sensory inputs, supporters claim, makes subjects better able to sense telepathic signals, and results in a far higher than chance ability to select the correct target patterns.

The gist of Taylor's article is that these positive results -- well beyond what would be considered statistically significant support for psi -- are being ignored by the scientific establishment because of an entrenched bias against anything that's "paranormal."  Taylor writes:

In recent years, a series of studies showing significant results from psi phenomena have been published in a whole range of major psychology journals.  A number of comprehensive overviews of the evidence have also been published.  Most notably, last year American Psychologist carried an article by Professor Etzel Cardeña entitled “The experimental evidence for parapsychological phenomena: A Review.”  Cardeña showed clearly that the evidence for phenomena like telepathy, precognition and clairvoyance has proven so significant and consistent over a massive range of difference experiments that it cannot simply be explained away in terms of fraud, the “file drawer” effect (when researchers don’t bother to publish negative results) or poor methodology.  Cardeña also showed that there is no reason at all to take the view that these phenomena break the laws of science, science they are compatible with many of the theories and findings of quantum physics (which is why many quantum physicists have been open to their existence.)

As I mentioned in a previous post, it drives me nuts when people start attributing psychic phenomena to quantum physics, because those associations are usually based upon scant knowledge of what quantum physics actually says.  But let's look past that for now.  Taylor goes on to say that the evidence has been mounting for years:

A meta-analysis of more than three thousand Ganzfeld trials that took place from 1974 to 2004 had a combined ‘hit rate’ of 32 per cent.  A seven percent higher than chance rate may not seem so impressive, but over such a large number of experiments, this equates to odds of thousands of trillions to one—and a figure far too significant to explained in terms of the file drawer effect.  In addition, in Ganzfeld experiments that have been undertaken with creative people, there has been a significantly higher than normal rate of success.  In 128 Ganzfeld sessions with artistically gifted students at the University of Edinburgh, a 47% success rate was obtained, with odds of 140 million to one.  Similarly, in a session with undergraduates from the Juilliard school of performing arts, the students achieved a hit rate of 50%.

If these figures are correct, then Taylor's right; this is evidence that demands an honest analysis.  As skeptics, we can't just pay attention to the evidence that lines up with the way we already decided the world works, and ignore everything else.  So let's take a look at his claim.

In 1999, Richard Wiseman and Julie Milton, of the University of Hertfordshire and the University of Edinburgh respectively, published a meta-analysis of ganzfeld results in the Psychological Bulletin.  Wiseman and Milton were unequivocal:

The new ganzfeld studies show a near-zero effect size and a statistically nonsignificant overall cumulation.  Out of three autoganzfeld internal effects that the new database examined, only one effect was replicated, and it turns out to have been mistakenly reported by Bern and Honorton (1994) as having been statistically significant in the autoganzfeld studies...  Whatever the reason, the autoganzfeld results have not been replicated by a "broader range of researchers."  The ganzfeld paradigm cannot at present be seen as constituting strong evidence for psychic functioning.

The pro-psi researchers then launched their own rebuttal.  A paper by Daryl Bem, John Palmer, and Richard S. Broughton in the Journal of Parapsychology, published in September of 2001, didn't argue with Wiseman and Milton's analysis, but said that there were ten new studies, and when those are added to the ones analyzed by Wiseman and Milton, "the overall ganzfeld effect again becomes significant."  Thus they stood firm on claims Daryl Bem and Chuck Honorton had made seven years earlier, when they had published their own meta-analysis in Psychological Bulletin in which they stated outright that "the psi ganzfeld effect is large enough to be of both theoretical interest and potential practical importance."

Here's where we get into murky water.  Psychological researcher Susan Blackmore, who has a well-deserved reputation for being one of the clearest, most open-minded thinkers on the subject -- and who herself is not willing to dismiss psi out of hand -- clobbered Bem and Honorton in a 2017 article in Skeptical Inquirer, stating that they had included in their analysis a series of studies by Carl Sargent that had been widely criticized for methodological flaws, and in which "the better the quality of the study, the smaller the apparent psi effect."  More troubling still is that Bem and Honorton, apparently deliberately, never mentioned Sargent's name as the source of some of their data, knowing that -- quite rightly -- this would cast doubt over their whole analysis.  Blackmore writes:

They also admitted that “One laboratory contributed 9 of the studies.  Honorton’s own laboratory contributed 5…  Thus, half of the studies were conducted by only 2 laboratories.” (Bem & Honorton, 1994, p 6).  But they did not say which laboratory contributed those nine studies.  Even worse they did not mention Sargent, giving no references to his papers and none to mine.  No one reading their review would have a clue that serious doubt had been cast on more than a quarter of the studies involved. 

I have since met Bem more than once, most recently at one of the Tucson consciousness conferences where we were able to have a leisurely breakfast together and discuss the evidence for the paranormal.  I told Bem how shocked I was that he had included the Sargent data without saying where it came from and without referencing either Sargent’s own papers or the debate that followed my discoveries.  He simply said it did not matter.

But one study -- and one researcher's apparent shoulder-shrug at including debunked studies in his analysis -- doesn't mean much.  There was an in-depth analysis done in 2013 by Jeffrey Rouder, Richard Morey, and Jordan Province, published in Psychological Bulletin, that had the following to say:

Psi phenomena, such as mental telepathy, precognition, and clairvoyance, have garnered much recent attention.  We reassess the evidence for psi effects from Storm, Tressoldi, and Di Risio's (2010) meta-analysis...  We find that the evidence from Storm et al.'s presented data set favors the existence of psi by a factor of about 6 billion to 1, which is noteworthy even for a skeptical reader.  Much of this effect, however, may reflect difficulties in randomization: Studies with computerized randomization have smaller psi effects than those with manual randomization.  When the manually randomized studies are excluded and omitted studies included, the Bayes factor evidence is at most 330 to 1, a greatly attenuated value.  We argue that this value is unpersuasive in the context of psi because there is no plausible mechanism and because there are almost certainly omitted replication failures.

And because there can never be enough meta-analyses, researcher and skeptic Andrew Endersby did his own in 2005, and had the following to say:

At the end of my research I find a hit rate of between 28.6% and 28.9% depending on certain choices concerning which scoring methods to use on particular experiments.  This doesn't have quite the headline grabbing appeal of 1 in 3 instead of 1 in 4 but the hit rate is still highly significant for 6,700 sessions.  However, this contains all experiments.  Flawed or not, standard or not.  There's no doubt that this figure can be tweaked up or down according to ruling in or out certain experiments.

Not exactly a ringing proclamation of support.

So where are we now?  Same place, pretty  much.  You've got your true believers, your fervent disbelievers, and people in the middle like myself who would very much like to know if there's actually something there to study.  Because if the ganzfeld effect actually works, it would be kind of earthshattering, you know?  It would mean that there actually was a mechanism for information transfer between minds, and would overturn the basic assumption we have about neuroscience -- that what occurs in your mind is solely the result of electrical and chemical signaling within your own skull.  Even The Skeptic's Dictionary -- usually squarely on the side of the scoffers -- is unwilling to discount it out of hand.  Here's how the entry for the ganzfeld effect ends:

Actually, what we know is that the jury is still out and it probably will never come in if the best that parapsychologists can come up with is a statistic in a meta-analysis that is unlikely due to chance.  Even if we take the data at face value, we know that no matter how statistically significant the results are, the actual size of this psi effect is so small that we can’t detect it in a single person in any obvious way.  We have to deduce it from guessing experiments.  What hope do we have of isolating, harnessing, or expanding this power if a person who has it can’t even directly recognize its presence?

I'll end with another quote from Susan Blackmore, which I think is spot-on.  If anyone has replicable, well-controlled experiments showing the existence of psi, I'm more than willing to consider them.  But until then:

Perhaps errors from the past do not matter if there really is a repeatable experiment.  The problem is that my personal experience conflicts with the successes I read about in the literature and I cannot ignore either side.  I cannot ignore other people's work because science is a collective enterprise and publication is the main way of sharing our findings.  On the other hand I cannot ignore my own findings—there would be no point in doing science, or investigating other people's work, if I did.  The only honest reaction to the claims of psi in the ganzfeld is for me to say "I don't know but I doubt it. "

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This week's Skeptophilia book recommendation is a brilliant look at two opposing worldviews; Charles Mann's The Wizard and the Prophet.  Mann sees today's ecologists, environmental scientists, and even your average concerned citizens as falling into two broad classes -- wizards (who think that whatever ecological problems we face, human ingenuity will prevail over them) and prophets (who think that our present course is unsustainable, and if we don't change our ways we're doomed).

Mann looks at a representative member from each of the camps.  He selected Norman Borlaug, Nobel laureate and driving force behind the Green Revolution, to be the front man for the Wizards, and William Vogt, who was a strong voice for population control and conversation, as his prototypical Prophet.  He takes a close and personal look at each of their lives, and along the way outlines the thorny problems that gave rise to this disagreement -- problems we're going to have to solve regardless which worldview is correct.

[If you purchase the book from Amazon using the image/link below, part of the proceeds goes to supporting Skeptophilia!]

ESP (Extra-Sexy Perception)

Daryl Bem, an experimental psychologist of some standing, has an obsession; proving that ESP exists.  He's been at this for decades.  He was one of the researchers who designed the Ganzfeld Experiment back in the 1980s, in which people were placed in sensory deprivation and allegedly could communicate telepathically.  (Other scientists, naturally wishing to see if they could replicate these results, couldn't.)

He's still at it, almost thirty years later, and published a paper last month in the Journal of Personality and Social Psychology in which he basically says, "Now I've done it!  See?"

Unfortunately for Bem, this piece of research is (1) once again generating results that most other scientists don't consider significant, and (2) may be one of the most unintentionally funny experimental designs I've ever heard.

What he did was to take a bunch of college students, and place them in front of two computer screens.  The students were equipped with sensors that detected which way their eyes were moving.  Then they were shown pairs of photographs on the two screens.  The pairs of photographs were made up of (1) an innocent photograph like a landscape or a puppy, and (2) a photograph of people having sex.  Bem's claim was that based on the eye movements of the students, they anticipated the screen with the erotic photograph "significantly more than fifty percent of the time."

The experiment was repeated with other types of photographic pairings, and no effect was found.

So, if you accept Bem's results -- ESP works, but only if sex is involved.

Bem writes, with an apparent straight face, "The presentiment studies provide evidence that our physiology can anticipate erotic stimuli before they can occur.  Such anticipation would be evolutionarily advantageous for reproduction and survival if the organism could act instrumentally to approach erotic stimuli and avoid negative stimuli."

Sure.  That makes total sense.  If a guy sees a woman making sexual advances toward him, it's gonna help him out if he's ready to rock and roll 0.1 seconds before she is.  Because we all know how slow guys are to get aroused.  Excuse me while I take a momentary break to guffaw.  All of which tells me that whatever he knows about psychology, the guy (1) doesn't understand evolutionary theory, and (2) apparently has never gotten laid.

Bem's paper also describes a variety of other experiments he conducted.  My favorite was one in which he found that studying after a test makes your score better.  Yes, you read that right.  In Bem's words:  "The results show that practicing a set of words after the recall test does, in fact, reach back in time to facilitate the recall of those words."  I hope my students don't find out about this.  I have a hard enough time getting them to study as it is.

And of course, no woo-woo article would be complete without a mention of quantum physics.  Bem writes, "Those who follow contemporary developments in modern physics, however, will be aware that several features of quantum phenomena are themselves incompatible with our everyday conception of physical reality."

As far as I can tell, this means, "Quantum physics is kinda weird.  ESP is also weird.  Quantum physics is real.  Therefore ESP is real.  Q.E.D."

There's also the problem that other psychologists did a statistical analysis of Bem's results, and found that "the evidence for psi is weak to nonexistent."  Given that this criticism was published in the same issue of JPSP, you have to wonder how Bem's paper got past the peer review process in the first place.

Anyway, Bem claims that his research shows that if ESP exists, (1) it will help you to locate pornography, and (2) allow you to study after you take tests.   All of which explains vividly why his findings would appeal to college students.  If he could add another experiment that showed (3) a method for dowsing for beer, I think he'd be the most popular researcher on US college campuses.