Neuroimaging Used in Attempts to Resolve the Psi Debate

by Guy Lyon Playfair

The paper ‘Using Neuroimaging to Resolve the Psi Debate’ by Samuel T. Moulton and Stephen M. Kosslyn (Journal of Cognitive Neuroscience 20 (1), 2008) must have brought tidings of great joy to sceptics. Not only do the Harvard University psychologists claim their findings to be ‘the strongest evidence yet obtained against the existence of paranormal mental phenomena’, but add that if they are sufficiently replicated, ‘the case will become increasingly strong, with such certainty as is allowed in science, that psi does not exist.’

They reach these conclusions after a lengthy series of telepathy/clairvoyance tests in which sixteen closely bonded pairs (parent/child, brother/sister, twin, roommate) took part. One of each pair was put in a magnetic resonance imaging machine, enabling the researchers to see the brain at work as it dealt with incoming stimuli, while the other was taken to another room, shown a picture and asked to transmit it mentally to the one in the machine, who was shown the same picture plus a control one, and asked to guess which one had supposedly been sent by psi by pressing a button.

Results were almost exactly at the 50% chance level (1842 correct guesses out of 3687, or 49.9%). The authors found no differences at all in the brain scans made when guesses were right or wrong. Hence their conclusions quoted above.

They do concede that there is evidence for what many believe to be psi, and cite one of Louisa Rhine’s spontaneous cases in which a mother woke at 4 am feeling her son was calling to her for help, and learned later that he had been shot at exactly that time.

Ah, they say, but this is only anecdotal evidence, which is known to be beset by ‘cognitive bias’, ‘availability error’, ‘confirmation bias’, ‘illusion of control’ and ‘bias blind spot’. One or more of these ‘may explain apparently paranormal evidence that people report’. In any case, ‘the positive evidence that has been reported is merely ‘anomalous’,’ and ‘despite widespread public belief in [psi] phenomena and over 75 years of experimentation, there is no compelling evidence that psi exists.’

Having thus dismissed all human testimony because of its ‘inherent uninterpretability’ (an attitude fortunately not adopted in courts of law), the authors reveal their own set of biases by giving a shamefully sloppy and tendentious account of previous lab experiments. Researchers from Myers to Honorton and Sheldrake who have reported positive results are mentioned briefly in passing without readers being given much idea of what they actually did. Meta-analyses are dismissed with a wave of the hand because of their ‘instability’. No mention of the frequently replicated decline or sheep-goat effects. More inexcusably, no mention either of at least five MRI studies (Standish, Achterberg, Kozak et al.)* that did find evidence for psi. So why didn’t Moulton and Kosslyn?

The obvious answer: there wasn’t any in their experiments. Or if there was, the signal was lost in the noise as receivers were asked to make 240 guesses over a 90-minute period. They could not possibly have reached the relaxed state essential for telepathic reception in an hour and a half of non-stop guessing and button pressing.

It seems from the authors’ general tone that this was the result they wanted and expected, and although they concede that ‘absence of proof is not proof of absence’ the title of their paper strongly implies that the psi debate has been solved. One negative result has cancelled more than a century of positive ones.

No serious psi researcher would ever claim to have proved psi to exist. Proof, in 21st century science, is confined to mathematics. Elsewhere, there are only probabilities, and as all those meta-analyses have shown, despite their alleged and undefined ‘instabilities’, the probability that all published (by definition no longer anecdotal) case histories and controlled lab experiments can be explained by chance alone is microscopic to the point of invisibility.

The real debate is between those on whose research these findings are soundly based and those who list spurious reasons to reject that research en bloc. If articles like this one continue to be published, the debate will go on for ever.

* For a summary, see R.A.Charman (2006). ‘Direct brain to brain communication – further evidence from EEG and fMRI studies.’ Paranormal Review October, 3-9.