Wednesday, January 23, 2008

Guest Blog: Using Brain Imaging as a Direct Test for Psi

Despite impressive statistical evidence, there are still a number of skeptics and critics of parapsychology who say that they still do not find the case for psi phenomena convincing largely because there is still no developed theory that relates psi to human brain functioning. As a case in point, professional skeptic Michael Shermer (2003) once wrote in his monthly op-ed column in Scientific American that, with respect to telepathy, “Until psi proponents can elucidate how thoughts generated by neurons in the sender’s brain can pass through the skull and into the brain of the receiver, skepticism [that psi exists] is the appropriate response…” (p. 32). While it seems that the mechanism may be a bit more complex than the simple picture Shermer paints of it, he does at least have a fair point in that the search for the neuropsychological correlates of psi should be an important focus for parapsychology if it looks to ever achieve wide mainstream acceptance.


Over the years, the search has largely been limited to using scalp electrodes connected to an electroencephalograph (EEG) in order to look for any brain wave patterns that might be associated with psi functioning (Ehrenwald, 1977). However, with the advent of brain imaging technology, there is the promise of peering through the skull to get a possible glimpse of the brain areas that might be involved. This promise is apparently what spurred the design of a new study just published in the latest issue of the Journal of Cognitive Neuroscience (Moulton & Kosslyn, 2008), which focused on the attempt to test for ESP using functional magnetic resonance imaging (fMRI). The study actually represents an attempt by mainstream researchers to experimentally reproduce psi effects, and was conducted by Samuel Moulton, a graduate student in the psychology department of prestigious Harvard University, along with Stephen Kosslyn, the prominent psychologist best known for his brain studies on mental imagery and visual perception (e.g., Ganis et al., 2004).


The premise for the study was based in part on a series of studies by Norman Don, Bruce McDonough, and Charles Warren of the University of Illinois at Chicago, in which they recorded the event-related brain wave potentials (ERPs) [1] of participants engaged in a precognition test disguised as a gambling task (Warren et al., 1992; Don et al., 1998; McDonough et al., 2002). They found that, in cases where they had correctly selected the precognition target, the participants’ ERPs were significantly different in wave structure from the ERPs associated with incorrect selections, suggesting that, on a brain wave level, the participants were sub-consciously “responding” more distinctly to the correct ESP target. Moulton and Kosslyn predicted that the brain as a whole might act similarly, the result of which might be detectable using MRI.


To test this, they gathered 19 pairs of people who were emotionally or biologically related [2] for a telepathy-type test, with one being the sender and the other being the receiver. The receiver’s head was placed into the MRI scanner and they were shown (by way of a mirror) two pictures during each test trial, one of which had been randomly selected as the ESP target. They selected which of the two they thought was the target by a button press and were given feedback (with a 50/50 chance of being right) a few seconds after, all while being scanned by the MRI. In another room, the sender viewed the actual target pictures for each trial, attempting to “send” their contents to the receiver.


The overall results indicated that the receivers had correctly chosen the ESP target about 50% of the time, exactly at the level expected by chance alone, thus indicating no evidence of ESP. As a group, the receivers’ MRI scans also did not reveal any difference in brain activity between correct and incorrect trials, although at least one participant had shown less activity in several brain areas (with most reduction being in the temporal lobe) during correct trials as compared to incorrect trials. Given that this participant was the only one to show this reduction, as well as the scanning artifacts that can potentially occur in MRI, it is difficult to tell whether this result was meaningful or not. In all, Moulton and Kosslyn conclude that their study constitutes strong evidence against ESP.


Although the study was innovative and thus seemed promising, there were a few issues about psi that may account for the reason no clear brain correlates were found. Moulton and Kosslyn seemed to assume from the outset that ESP is fundamentally different from normal sensory perception, in that it should evoke neural patterns distinct from those for sensory perception (p. 183). This does not seem to fit well with what ESP may be trying to tell us when looked at up close. Unlike normal sensory perception, ESP has no characteristic experience to call its own; there is nothing in the ESP experience that clearly tells us that any (sensory) part of the experience is a feature of ESP only. Instead, ESP is multi-sensory, and seems to incorporate the same sensory modes that we use in normal perception, only in the absence of stimuli (e.g., people say that they see or hear things during an ESP experience, just as they would in normal perception). In other words, ESP appears to be sensory perception in borrowed garb. If ESP really does “borrow” the sensory modes of ordinary perception, then we might expect the same brain areas active in ordinary perception to be active in ESP. This possibility may be indicated by the results of two MRI studies focusing on the telepathy-related phenomenon of sensory stimulation at a distance (Richards et al., 2005; Standish et al., 2003). In the studies, a sender was presented with an intense stimulus (a bright flash) in one room, which was expected to activate the main visual regions in the occipital cortex in the back of the brain. In the MRI room, the receiver in the scanner had shown activation of that same visual region at the same time that the sender saw the flash, despite the fact that the sender’s main visual pathway was blocked (their eyes were covered by opaque goggles). Since the stimuli in Moulton and Kosslyn’s study were pictures, we might also expect the visual regions to be active. A look at the MRI images published in their report indicates that they were, both in the psi and non-psi conditions. If the above view has any merit, then it may have been the case that the psi-related activity was simply “masked” by its shared functional regions with visual perception (this also assuming that some degree of ESP was present in their data despite being statistically undetectable; recall that the results on the ESP test were at chance). Also, it is possible that the psi signal is so weak that it is barely indistinguishable from the wide degree of noise that may be present in MRI scanning, again assuming that there was any ESP at all. Given the chance results, we can hardly expect a brain correlate to be visually apparent if there was no evidence for ESP in the study. For these reasons, using brain imaging itself as a direct test for psi may not be a good choice use of the technology.


Furthermore, to really seek out the possible brain correlates of psi, we may have to instead turn to those who have them more often than ordinary people (psychics), and see how their brains may differ (if they do at all) from ordinary people. Some preliminary results seem to suggest very slight structural differences (Persinger et al., 2002; Roll et al., 2002), but this work needs to be followed up on in order to give clearer answers. As much as I admire Kosslyn, it seems that any studies he does in this area will need to take a bit more careful consideration of their underlying assumptions.


- Bryan Williams


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Bryan Williams is a Native American student at the University of New Mexico, where his undergraduate studies have focused on physiological psychology and physics. He is a student affiliate of the Parapsychological Association, a student member of the Society for Scientific Exploration, and a co-moderator of the Psi Society, a Yahoo electronic discussion group for the general public that is devoted to parapsychology. He has been an active contributor to the Global Consciousness Project since 2001, and was the recipient of the Charles T. and Judith A. Tart Student Incentive Award for Parapsychological Research from the Parapsychology Foundation in 2003. As of August 2007, he is the author of seven articles (two co-authored with William G. Roll) that have appeared in the Proceedings of the Parapsychological Association Convention. His native ancestry lies with the Laguna Pueblo in western New Mexico, and the tribe’s long-held beliefs in survival and the concept of spirits is one of the things that spurred his interest in parapsychology.


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Notes

[1] Event-related potentials are tiny changes in electrical voltage detectable along the surface of the scalp, which are usually the result of sensory stimulation.


[2] This is based on findings suggesting that psi experiences tend to be more common among people who are emotionally close or are members of the same family (e.g., Broughton & Alexander, 1997).


References:

Broughton, R. S., & Alexander, C. H. (1997). Autoganzfeld II: An attempted replication of the PRL ganzfeld research. Journal of Parapsychology, 61, 209 – 226.


Don, N. S., McDonough, B. E., & Warren, C. A. (1998). Event-related brain potential (ERP) indicators of unconscious psi: A replication using subjects unselected for psi. Journal of Parapsychology, 62, 127 – 145.


Ehrenwald, J. (1977). Psi phenomena and brain research. In B. B. Wolman (Ed.) Handbook of Parapsychology (pp. 716 – 729). New York: Van Nostrand Reinhold.


Ganis, G., Thompson, W. L., & Kosslyn, S. M. (2004). Brain areas underlying visual mental imagery and visual perception: An fMRI study. Cognitive Brain Research, 20, 226 – 241.


McDonough, B. E., Don, N. S., & Warren, C. A. (2002). Differential event-related potentials to targets and decoys in a guessing task. Journal of Scientific Exploration, 16, 187 – 206.


Moulton, S. T., & Kosslyn, S. M. (2008). Using neuroimaging to resolve the psi debate. Journal of Cognitive Neuroscience, 20, 182 – 192.


Persinger, M. A., Roll, W. G., Tiller, S. G., Koren, S. A., & Cook, C. M. (2002). Remote viewing with the artist Ingo Swann: Neuropsychological profile, electroencephalographic correlates, magnetic resonance imaging (MRI), and possible mechanisms. Perceptual and Motor Skills, 94, 927 – 949.


Richards, T. L., Kozak, L., Johnson, L. C., & Standish, L. J. (2005). Replicable functional magnetic resonance imaging evidence of correlated brain signals between physically and sensory isolated subjects. Journal of Alternative and Complementary Medicine, 11, 955 – 763.


Roll, W. G., Persinger, M. A., Webster, D. L., Tiller, S. G., & Cook, C. M. (2002). Neurobehavioral and neurometabolic (SPECT) correlates of paranormal information: Involvement of the right hemisphere and its sensitivity to weak complex magnetic fields. International Journal of Neuroscience, 112, 197 – 224.


Shermer, M. (2003). Psychic drift. Scientific American, 288, 32.


Standish, L. J., Johnson, L. C., Kozak, L., & Richards, T. (2003). Evidence of correlated functional magnetic resonance imaging signals between distant human brains. Alternative Therapies in Health and Medicine, 9, 128, 122 – 125.


Warren, C. A., McDonough, B. E., & Don, N. S. (1992). Event-related brain potential changes in a psi task. Journal of Parapsychology, 56, 1 – 30.

11 comments:

Sam Moulton said...

Greetings,

Our design does not assume, as you assert, that a psi stimulus is processed differently than a sensory stimulus; if anything, it assumes just the opposite: that psi is comparable to sensory perception. If psi exists and is processed by sensory cortices, then the psi stimuli in our experiment, as compared to the non-psi stimuli, should have evoked brain activation that was similar in anatomy but smaller in magnitude. This would be a psi analog of a well-established effect in cognitive neuroscience: repetition suppression (see p. 183 of our article). If an individual is subliminally exposed to a visual stimulus, this subliminal exposure suppresses their subsequent response to that stimuli. In our experiment, we replaced that initial subliminal presentation with a psi presentation, to see whether it dampened the neural response in a similar fashion.

Hope this clarifies things.

Best,
Sam

david said...

The "subliminal" psychic response if there was one doesn't need to have been entirely or at all visual - instead a knowing of some kind or an intuition. Thus there would not be any suppression expected.

That this experiment didn't show positive results shows nothing more nor less than that in one experimental series with this experimental design and selected participants psi was not demonstrated, and it failed to confirm McDonough and Warren's prediction that their positive results with the wave structure of ERPs might also be detectable using fMRI imaging.

I agree with Bryan Williams that fMRI imaging is probably not a good method for such investigation, because of its nature in showing simple activity or inactivity of large masses of neurons (rather than fine patterns of electrical potential in time and amplitude). As Bryan stated, it is difficult to tell whether the study result was meaningful or not. To conclude that the study constitutes strong evidence against ESP goes much farther than the results warrant, except in the minds of staunch psi skeptics looking for any evidence to dismiss it. In particular because one negative study can't invalidate hundreds of other positive experimental studies with different designs and participants, and the meta-analyses based on them.

w.e.cousins said...

Interesting post and follow-ups. Whatever short-comings fMRI imaging may or may not have when it comes to investigating psi, at least it can be said that no ping-pong balls were hurt or injured during the course of the experiment. Wolfgang Metzger must be be spinning in his grave... ;)

Anonymous said...

Telepathy experiments are but one way to search for "extraordinary" event generation, viv-a-vis the brain. "Star performers" like www.gillismagic.com/sisue.html (and others), could expand the knowledge of functional neuroanatomy, should people get past the "boggle factor" of acceptance.

Patrizio said...

Are we sure that the procedure adopted to obtain a telephatic trasmission of information was correct? "Senders viewed each stimulus for 10–22 sec, depending upon timing of the receivers’ stimulus presentations. The investigator asked senders to ‘‘influence the receiver’’ with the psi stimulus, adopt a ‘‘playful’’ attitude.
The receivers had between 2 and 6 sec to respond depending upon the trial, and their responses did not advance the script. Following this forced-choice response, participants were presented with the psi stimulus (1-sec duration) and feedback (for other details see the paper).
After hundreds of experiments to test telepathic trasmission of information (i.e. those using ganzfeld) it is clear that the procedure used by Moulton & Kosslyn has the characteristics to do not obtain any behavioral result and consequentely any neurophysiological signal

Patrizio said...

Are we sure that the procedure adopted to obtain a telephatic trasmission of information was correct? "Senders viewed each stimulus for 10–22 sec, depending upon timing of the receivers’ stimulus presentations. The investigator asked senders to ‘‘influence the receiver’’ with the psi stimulus, adopt a ‘‘playful’’ attitude.
The receivers had between 2 and 6 sec to respond depending upon the trial, and their responses did not advance the script. Following this forced-choice response, participants were presented with the psi stimulus (1-sec duration) and feedback (for other details see the paper).
After hundreds of experiments to test telepathic trasmission of information (i.e. those using ganzfeld) it is clear that the procedure used by Moulton & Kosslyn has the characteristics to do not obtain any behavioral result and consequentely any neurophysiological signal

Patrizio said...

Are we sure that the procedure adopted to obtain a telephatic trasmission of information was correct? "Senders viewed each stimulus for 10–22 sec, depending upon timing of the receivers’ stimulus presentations. The investigator asked senders to ‘‘influence the receiver’’ with the psi stimulus, adopt a ‘‘playful’’ attitude.
The receivers had between 2 and 6 sec to respond depending upon the trial, and their responses did not advance the script. Following this forced-choice response, participants were presented with the psi stimulus (1-sec duration) and feedback (for other details see the paper).
After hundreds of experiments to test telepathic trasmission of information (i.e. those using ganzfeld) it is clear that the procedure used by Moulton & Kosslyn has the characteristics to do not obtain any behavioral result and consequentely any neurophysiological signal

Patrizio said...

Are we sure that the procedure adopted to obtain a telephatic trasmission of information was correct? "Senders viewed each stimulus for 10–22 sec, depending upon timing of the receivers’ stimulus presentations. The investigator asked senders to ‘‘influence the receiver’’ with the psi stimulus, adopt a ‘‘playful’’ attitude.
The receivers had between 2 and 6 sec to respond depending upon the trial, and their responses did not advance the script. Following this forced-choice response, participants were presented with the psi stimulus (1-sec duration) and feedback (for other details see the paper).
After hundreds of experiments to test telepathic trasmission of information (i.e. those using ganzfeld) it is clear that the procedure used by Moulton & Kosslyn has the characteristics to do not obtain any behavioral result and consequentely any neurophysiological signal

Phronk said...

It's an interesting study and I'm glad it was done. However, absence of evidence is not evidence of absence.

Plenty of MRI studies have obtained null results. But an fMRI study involving vision failing to confirm its hypotheses does not establish that vision does not exist.

buzz said...

"Until psi proponents can elucidate how thoughts generated by neurons in the sender’s brain can pass through the skull and into the brain of the receiver, skepticism [that psi exists] is the appropriate response.."

That suggests it is necessary to have a theory to explain a phenomenon before we can acknowledge that the phenomenon happens.

Moreover, Shermer assumes that thoughts are "generated" by neurons. This is like saying turn signals are generated by the turn signal switch, and the honk is generated by a horn.

We haven't looked into the possibility that the car has a driver who operates these signals, so we believe the car generates them.

What is more likely is that thoughts are generated by the sender, who is not trapped in a skull, thus there is no need for thoughts to pass through media.

We would do better to investigate the properties of the sender and receiver rather than dismiss psi because we have no theory by which it could comply with inapplicable models.

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