Jan 07 2008

Looking for ESP in the Brain

A recently published study uses functional MRI to look as brain function in response to possible extra-sensory perception (ESP) stimuli. The study was negative, leading the authors to conclude:

These findings are the strongest evidence yet obtained against the existence of paranormal mental phenomena.

While that might be overstating it a bit, it was an interesting new approach to the question of ESP. Study authors, Samuel Moulton, a graduate student in the department of psychology at Harvard University, and Stephen Kosslyn, also at Harvard, decided to look for ESP in the brain by imaging subjects with fMRI during ESP and non-ESP signals. The ESP signals consisted in one trial of an emotionally close person looking at the target image and attempting to telepathically send the image to the subject, who was also looking at the image. A second trial involved a computer screen in another room with the target image (testing clairvoyance). And a third trial involved displaying the image to the subject again after the trial (testing precognition).

The premise of the study (which is well established) is that the brain responds less to stimuli that it has seen before (even subliminally), and more to stimuli that it anticipates. So the authors hypothesized that if the subjects were exposed to the target stimuli through telepathy or clairvoyance (even if they were not consciously aware of it) their brain should display an increased response. In all the trials there was no difference in brain response between subjects with and without an ESP stimulus.

What does this study actually show? That question cuts to the current difficulty of ESP research – namely that no one knows what ESP is supposed to be, and this cuts both ways. For example, in this study, the authors had to make many assumptions about how ESP works in order to decide what should happen (increased or decreased brain response to stimuli) in response to ESP. Their hypotheses are all reasonable, and the fact that they are negative is one more piece of evidence that casts doubt upon the existence of psi. But it does not, and cannot, rule out any ESP phenomena. That is primarily because ESP is not currently constrained mechanistically.

In other words, there is no scientific model for how ESP can work – no mechanism. Some proponents make hand-waving speculations about quantum entanglement or cosmic consciousness, but these are ultimately meaningless gibberish. There is no proposed mechanism for ESP that amounts to a reductionist model based upon established physics or biology. No one has even established any physical features to ESP – meaning that it displays consistent characteristics, such as decreasing with distance, or being blocked by dense substances, or anything. There has been zero progress in zeroing in on what ESP might be as a physical phenomenon.

The simplest explanation for this utter lack of any progress characterizing a possible mechanism for ESP is that ESP does not exist. This new study mostly just adds to the string of negative studies looking for a possible mechanism or even physical sign of ESP. This, unfortunately, will never give us ultimate closure because it is impossible to prove a negative – that no type of ESP exists anywhere, anytime. But the longer we look with negative results, the more confident we can become in the conclusion that ESP probably does not exist.

The lack of a possible or even hypothetical mechanism for ESP also means that ESP research is limited to anomaly hunting. All studies that propose to look for ESP (for example the research of Dean Radin or Rupert Sheldrake) are not looking for ESP (because no one knows what ESP is) but rather are looking for anomalies. In fact some researchers more honestly label what they are looking for as “anomalous cognition.”

Let’s take the Ganzfeld experiments, for example. This is an automated test for clairvoyance- the ability to remotely view a target. Subjects were given four pictures to choose from, one of which was the target picture, displayed in another room. Random guessing would produce a hit rate of 25%. Some Ganzfeld researchers claimed hit rates much higher – although the Ganzfeld experiments ultimately failed to be replicated and under tight methods eventually the effect size shrunk to near zero.

Without getting into all the details, my reading of the ESP literature is that there is yet to be an experiment that survives the process of peer-review and replication. Even proponents have to admit that ESP researchers have not yet come up with a trial design that produces a reliable signal. Signals over time tends to go away and ultimately fail to be replicated – although there are always new trial designs coming down the pike. So as yet there is not even an anomaly to explain.

But let us say, hypothetically, that an ESP study demonstrates a reliable signal. That would not demonstrate ESP, it would only demonstrate an anomaly. In so-called ESP studies (again, more properly termed “anomalous cognition”) the design essentially is looking for some effect that cannot be explained by known means. So the definition of an ESP signal is always a negative one – an apparent effect that has no other explanation. This, of course, requires absolutely tight methodology (and the smaller the effect size the tighter the methods have to be), because you cannot prove a negative – in this case that there was no other cause for the apparent signal. The conclusion that there is no non-ESP cause is only as good as the degree to which all potential variables in the study were anticipated and controlled for.

Looking for anomalies is a legitimate part of scientific exploration – but it should be considered only the beginning of the process, not the conclusion. You cannot prove the existence of a specific phenomenon simply by pointing to an anomaly – that would constitute an argument from ignorance logical fallacy. In order to establish that ESP exists researchers would need to find a reliable anomaly and then show that the anomaly has certain features. These features would then suggest possible mechanisms, leading to specific hypotheses that can be tested. Eventually an underlying mechanism would come to light that explains the features of the anomaly. Hopefully research would also reveal a signature of ESP – some feature of the anomaly that is unique or at least highly suggestive of ESP and can be used as a positive signal for the presence of ESP.

None of this has happened. ESP researchers are stuck at step one – find an anomaly. They keep claiming that they have succeeded in this step, but so far their claims have not survived adequate review and replication. While proponents are still arguing about step one, the undeniable fact is that there is no research or evidence which takes ESP beyond step one, characterizing a new phenomenon or pointing the way toward a credible mechanism.

Proponents typically argue that the mechanism for ESP is simply too far outside any current scientific paradigm. That may be true (again, one cannot prove a negative) but that is not an argument to accept a claim for ESP. It is just another argument from ignorance. Until ESP is brought within what is known and established, we have nothing.

The history of science has taught us that alleged phenomena that are elusive to demonstrate, have no known mechanism, and display no positive features that can be used as a marker or signature – probably do not exist. That is the conclusion demanded by the principle of parsimony. A century of ESP research has displayed all the features of a non-existent phenomenon. This latest study adds one more strike to this long history.

19 responses so far

19 thoughts on “Looking for ESP in the Brain”

  1. NYCSkeptic says:

    One little typo – Rupert Sheldrake’s name is misspelled.

    While on the subject of Sheldrake, I just stumbled across his essay for the 2008 Edge Foundation’s question “What have you changed your mind about?” First off, he completely misrepresents skepticism by calling creationists skeptics. Secondly, I really don’t think he’s changed his mind about this subject at all and is justing twisting the purpose of the question to reiterate what he seems to have always believed.

    The essay can be found here:


  2. Scepticon says:

    I checked out the link abouve and found the following:

    As Stephen put it in 1893, ” The thinkers generally charged with skepticism are equally charged with an excessive belief in the constancy and certainty of the so-called ‘laws of nature’.

    Yeah, how deluded are we?

    Another great entry Steven, thanks.

  3. Roy Niles says:

    It occurs to me that the very label of “extra-sensory” perception was meant to imply that whatever “perceptions” were allegedly transferred and received, no human sensory mechanisms were involved that we had so far been able to identify. And it seems more than coincidental that proponents of ESP are also strong believers in supernatural agents as the likely facilitators of such a process.

    So they have pretty well set up defenses against any attempts to falsify their claims scientifically – but shouldn’t the ball then be in their court to demonstrate why these claims are anything more than speculation. Shouldn’t they have the burden of proposing efforts to find those “extra” senses scientifically, rather than scientists having or feeling any burden to waste more time in demonstrating that our known sensory apparatus doesn’t do what these proponents have already in effect admitted they don’t do?

    The ESP proponents (mostly motivated by fraudulent purpose in my opinion) should be interested in further experiments that show someone has actually received some of these messages regardless of whether such reception can be otherwise discernible. To my knowledge, they have instead been largely uncooperative in past attempts to demonstrate they could be right. Evidently they have more of a vested interest in not being proved wrong.,

  4. I’ve always wondered what phenomenon is happening when I see a large flock of birds appear to simultaneously change from one course to a new course. It is probably some type of sensory perception that humans don’t have. On the face, it appears to be some sort of collective consciousness. Anybody know?

  5. marblue says:

    I don’t think it’s some type of sensory perception we don’t have.


  6. Jim Shaver says:


    I’m sure there must be good internet references for bird flocking behavior, but I don’t have time now to look for them. But I believe that what you perceive as “simultaneous” course changes are in reality described by wave functions and the responses of individual birds. Each bird is following a relatively simple set of rules that governs its flocking behavior, and changes of direction in one area of the flock get transmitted as quickly propagating waves to other areas in the flock.

    I’ve seen computer models (again, no references for now) of flocking birds that look very realistic when played in real time. And as is probably true for birds, the rules of flocking behavior for the virtual birds is relatively simple, yet those simple rules produce a very organic, flowing movement in the flock. The algorithms in these simulations do not use any simultaneous “group knowledge” or “plan”. Each simulated bird behaves according to a few simple rules and an initial state, such as “flying southward with velocity vector v and position x,y,z”.

  7. jonny_eh says:

    Where dogs put into the MRI? Why not? What are the skeptics afraid of? Obviously Sheldrake is right then!

  8. Thanks Jim and MarBlue,
    I would be happy to read any books about this phenomenon. & the fact that you’re reading this particular blog means that you like the style of writing that I also like to read. So, if you happen to know of a good book about this phenomenon, I really will read the book. I find the incredible flocking direction/speed changes endlessly fascinating and there are always examples present to watch.
    It would seem possible, Jim, from what you’re writing that a flock could “naturally select” out any bird that can’t respond to all other individual bird’s changes. These flocks sometimes fly in giant ovals of space and change speed and direction literally in the blink of my eyes. Really…sometimes I blink and the birds are going another direction….all of them.

  9. daijiyobu says:

    Perhaps this is rather esoteric, but if you are into evolutionary theory (this does relate to ESP)…

    I would think that if there was such a thing as ESP, it would be evident (in some form) in the behavior of animals similar to humans — simians, for instance, and perhaps large-brained mammals like dolphins.

    It would evidence itself indirectly by behaviors that are truly inexplicable: prey obviously avoiding predators using information grossly outside of their sensory locus, and predators finding prey similarly.

    In other words, there would be a competitive edge to possessing ESP, and competitive pressures would select such a trait and likely increase such a trait’s strength over time.

    I’m not aware of such animal behavior, but what I am aware of, hugely, is the power of human imagination.

  10. the.Duke.of.URL says:

    What we know about the activity of the brain is that it works electrochemically, and that the signal, in engineering terms, is weak. What we know about the skull is that it is a good insulator. This makes it unlikely that any electrical signals are being successfully sent to another brain, where the signal has to penetrate another insulator.

    Of course, there may be another means of communication we are currently unaware of, but until we discover it, I think it is best to remain skeptical about ESP claims.

    By the way, Steven, I am not surprised that you are not getting the academic kudos you deserve from the Yale administration. My impression of them was always that they were good conformists, and you, thankfully, are not. Thank you for supporting Dave Colquhoun in his battle with his craven Provost. The previous comment that the Provost may have an “alternative” agenda is, I think, well taken.

  11. The skepTick says:

    Dean Radin uses this blogpost to support why he’s not a skeptic.

  12. Roy Niles says:

    I am apparently too distant to have been healed.

  13. psamathos says:

    Interesting, I didn’t know Kosslyn was interested in this kind of stuff. It’s good to see someone take a fresh approach to the “problem,” although it won’t affect the real issue: namely, the dual standard of evidence that paranormalists actively maintain for their research in contrast with mainstream science. But no amount of new research will fix that.

  14. llysenwi says:

    daijiyobu – I think it is very interesting to ask about what the effect of ESP would be in an evolutionary context. Intuitively, I would think that precognition would be such an advantageous characteristic that the real question is “why aren’t we all psychic?”. I do not know what the population frequency of psychics is, but I am guessing that it is far less than the near 100% frequency of other highly advantageous adaptations in humans, like the opposable thumb.

    Selection would not necessarily increase precognitive powers continually in animals. We are used to directional selection from domestic breeding programs (tinier dogs that fit in purses, cows that produce more milk, and sad-but-true leaner pigs). Optimal fitness in a dynamic natural environment tends to be a moving target, which leads to directional selection over short time scales and more complex patterns over long time scales (fish to terrestrial animals to whales is one example).

  15. Traveler says:

    An evolutionary aspect to ESP would only exist if ESP were a biological function controlled by genes. I’m sure you will find a number of ESP proponent who would tell you that it’s a gift from spirit guides, aliens or some other means not subject to natural selection.

    A more interesting question might be if there’s an evolutionary advantage to believing in pseudo-science and superstition. Maybe true believers can make faster (if more erroneous) decisions, and expend fewer calories on thought.

  16. adamsafron says:

    While I am sympathetic to Kosslyn’s intentions with this study, I think he’s being a bit naive philosophically:

    “These findings are the strongest evidence yet obtained against the existence of paranormal mental phenomena.”

    I think this overstates it a lot. Skeptics need to be careful not to overplay our hands lest we play into the hands of true believers by diluting our rhetoric. This single study is insignificant when compared with the mountain of evidence in the meta-experiment described by Dr. Novella. While Kosslyn is correct that a null result is meaningful if you have reason to believe that you should have detected the effect with your paradigm, his statements are much to broad to be justified. To his credit, he succeeded in demonstrating that appreciable psi effects do not exist under the range of conditions he tested.

    “If psi exists, it occurs in the brain, and hence, assessing the brain directly may be more sensitive than using indirect behavioral methods (as have been used previously).”

    Well, this kind of puts the cart before the horse in terms of convincing those with a penchant for making supernatural claims. Also, while measuring the brain is theoretically more sensitive than indirect behavioral methods, it is not necessarily more sensitive with our current tools. Presently, I’m not convinced that fMRI signal is superior to other methods for detecting general emotional arousal. Theoretically, brain metrics should be more sensitive, but fMRI signal is too crude of a measure to rule out more subtle neural effects.

    There are far more compelling reasons to be skeptical of paranormal claims. This study adds little to adjust my low probability assessment for the existence of ESP-type phenomena.

  17. davidsmith says:

    I agree with adamsafron that fMRI is not as powerful a tool as some would make out. It’s well established that the BOLD signal:noise ratio is about 1 to 2 orders of magnitude less than that from measuring local field potentials, so fMRI is missing alot of activity.

    Also, it’s usual for an fMRI study to show the result of a subtraction. Moulton and Kosslyn only published each condition (psi and non-psi) separately, leaving the reader to eyeball a comparison between each condition. Why did they do that? I would have much prefered the result of the subtraction showing no statistical differences…

  18. huntressristich says:

    I think that ESP is something that does not readily lend itself to scientific study. This is due to the fact that it involves individuals who are emotional creatures. The person being studied for ESP is liable to feel under pressure to perform, which could in itself confound the results. I think back to an episode of Johnny Carson where an India Yogi was supposed to levitate on air. He was seated in a box, which did not levitate, and in fact finally they showed him frantically bouncing around trying to levitate inside this cardboard box. How embarrassing and degrading an experience. One would wonder who would subject themselves to such blatant humiliation. Well, there may be many reasons why he went on TV.

    However, I know that when people are under pressure to perform, they can not be at their best. I myself had an experience in which I continually was guessing correctly at a task that would imply ESP. The persons involved were amazed that I was constantly guessing correctly and would not leave me alone. I finally gave up trying to give the correct answer. You see nothing good would come of it. Being wrong made me normal and like them.

    Another time I read a book about visualizing answers, it was very involved and I truly don’t remember the exact method. However, I tried the technique out with the lottery. This was at a time when there were only 5 numbers to match to win. I played one game only. I saw in my mind 4 correct numbers. I only missed one of the correct numbers. I won $80. I was very mentally drained by the visualization method. I vowed to never try it again. That was many years ago now. You don’t have to believe me. I have won small lottery prizes since then just having the machine choose the numbers, but I have never tried the visualization method again. As I say, it is so long ago I don’t even remember the name of the book I read or the exact method it taught. It was written by an Indian Yogi. I think the one on the Carson Show really believed he could levitate. In fact, I would not doubt if he had, but not on TV. I myself have seen objects levitate and move under their own power. I know others that have too, but they will never admit to it. I don’t know how it works, and can not do it myself at all. I just know it can be done.

    I am a very down to earth, practical person. I am not flighty and in fact am not religious or mystical in any way. I have felt pressured to make up “psychic” stuff to appease my “fans” at times too. That is part of being human, wanting to please and console people. Real ESP is a thankless, uncertain and never ending demand for answers from desperate people. It is not something that people who have it can just give out on demand without error. That is why science will never get the answers it wants through the oppressive exactitude of the scientific methods that are currently used to test for it.

    The best ESP comes in time of peril. That is really the only time ESP is very useful to those that possess it. Yet I like most people have come to push aside those psychic premenitions and to dismiss them. Why? For fear of being wrong and the terrible humiliation and embarrassment that I would be subjected to by people who want every thing to work like clockwork, like machinery. Because there is no room for being wrong ever. That is why people who could help never will. It would cause too much pressure to perform and to give comfort and right all the wrongs. It is not a panacea. Science and technology has in many ways led people to believe that everything that is correct works right every time or almost every time. I personally believe that ESP is most likely an ancient safety device that modern people just don’t need as much because they have devised better devices that are more foolproof ( like smoke detectors). That is why modern people have so little experience with using ESP and so little tolerance for failure of such safety devices.

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