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The Granqvist paper - ("Sensed presence and mystical experiences are predicted by suggestibility, not by the application of transcranial weak magnetic fields") - A flawed attempt at replicating the work of Dr. M.A. Persinger. - Comments by Todd Murphy, 2004

Dr. Pehr Granqvist omitted some crucial preparatory work and procedures in his experiment at Uppsala University , and Granqvist's conclusions overlook many of Persinger's procedures.

In contrast to the claim made by Granqvist, Persinger uses double-blind protocols. Here are a few sample papers where they were not only followed, but described in the papers. 1 2 3

Granqvist's procedures were an attempt at eliciting the 'sensed presence' experience. However, in Persinger's words his "methodology deviated significantly from the procedures known to evoke an experimental sensed presence."

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The software Granqvist used was provided by Persinger and Koren, but it required either a calibration program or a 286 PC. Stan Koren, technician for persinger's group, authored a calibration program which went into use shortly after the need for it was discovered (V. 1.4). Granqvist cannot be blamed because the bug wasn't found until after he was provided with the software (V. 1.15). He would have been sent another version had he stayed in touch. Granqvist reported using a Pentuim PRO PC, which would give it a processor speed between 166 and 200mhz. Granqvist's version of COMPLEX was written for the 286 series, with processor speeds close to 10 mhz. Pehr Granqvist ran his signals around ten times too fast.

Dr. Persinger publically stated (HERE) his view that the lack of communications between the two labs could have prevented the discrepency between the results. He also made the email correspondance between himself and the Swedish research group availble on the internet. (HERE)

Another point related to the software used in Persinger's lab is that it cannot be run under windows. Persinger's hardware connects to a PC through the LPT port (the printer port). Windows adds significant noise to the printer port's output - enough that it will "disconfigure the temporal patterns of the applied magnetic fields." Here's the reference for the paper that reported disruption of the signals under windows (4) The Granqvist paper mentioned that the PC used in his experiment was running windows 95. COMPLEX is a DOS program, and it doesn't work properly under Windows.

Although it's a good thing when significant research is replicated, getting the fields and signals wrong is liable to lead to failure, just like leaving out compounds in a chemical lab.

Persinger described the procedure he uses for television documentaries and colleagues: 9

"The experiences were most easily evoked if a frequency-modulated pattern (tailored after a "chirp" sequence from standard signal generators) was applied over the right hemisphere for 20 minutes and then a bilateral burst-firing pattern (designed after the discharge of amygdaloid neurons... ) was applied bilaterally over the temporal lobes for an additional 20 minutes note. These experiences occurred with equal vigor in dozens of reporters accompanying television film crews who have visited the laboratory during the last 10 years. The sensitivity of the functions of the right hemisphere to complex magnetic fields even within the picotesla range has been shown repeatedly by Sandyk.8"

In contrast, Granqvist applied the signals for only 15 minutes in each of the two phases. Even if he had used the calibration program, the shorter sessions make 'the sensed presence' and other similar experiences less likely. The difference of 5 minutes amounts to a 25% reduction in the length of the session, quite enough to eliminate reports from less-sensitive people, and influence the outcome of the experiment.

Another point worth noting is that Persinger used an acoustic chamber, while Granqvist used an "isolation" chamber. A significant portion of the temporal lobes activity is given over to monitoring ambient sound. The silence achieved in a proper acoustic chamber helps in eliciting the phenomena Persinger is known for, and it's replacement by a quiet isolation chamber deprives the sessions of true silence. This factor, while by no means decisive in Granqvist's failure to replicate Persinger's results, can reduce the number of experiences reported, as optimal conditions for the less-sensitive subjects are no longer present.

Granqvist's isolation chamber was significantly smaller than Persinger's, too. Two cubic meters instead of the seven used in Persinger's lab. A bit cramped. The picture shows Persinger's experimental chamber (really a small room) with a happy member of his team.

Granqvist is mistaken that Persinger's results are due to suggestion. In Persinger's experiments " ... the subjects were not aware of their experimental conditions and experimenters were not familiar with the hypotheses being tested or both were not aware of the experimental condition. Subjects were randomly or serially allocated to conditions. The person generating the hypothesis never had direct contact with the subjects."source Further, Persinger's results include cases where an experiment found one signal pleasant when applied over the right hemisphere 10, and a different signal more pleasant over the left. This precludes suggestibility as an explanation. In order for a researcher to get such reports through suggestability, they would have to plant very specific suggestions informing the subjects of the expected outcome. These results cannot be explained as suggestability except by recourse to accusations of fakery or an abandonment of sound procedure.

Granqvist's subjects were told that the experiment "was about the influence of complex, weak magnetic fields on experiences and feeling states". Persinger's subjects are told they are participating in an experiment concerning relaxation. If anything, Persinger's procedures are more 'blind' than Granqvist's.

If you tell a research subject that they're helping to study the 'influence' of 'magnetic fields' on 'feeling states', and then walk them through a room with an EEG in it, you'll have presented a suggestion - that they're going to experience neural stimulation. The subjects were given two cues about the nature of the experiment, one verbal (the experiment "was about the influence of complex, weak magnetic fields on experiences and feeling states"), and one visual (the EEG machine). It's not surprising that Granqvist's results correlated with suggestibility. The field configuration his subjects received was so distorted that the principle effects had no chance of appearing.

In addition to the studies that demonstrate hemispheric effects, there are also studies published reporting significant after-effects. In two studies,(4,6) Persinger and Baker-Price found lasting after-effects (a reduction in depression caused by closed head injuries). At this time of writing, similar results are being obtained with clinical depression in Texas. Follow-up for these studies lasted six weeks past the series of sessions. Subjects reported a reduction in depression and phobias. A result that can't be explained through suggestion.

These are relevant studies. They were done using the same hardware and one of the same signals as the better-known sessions seen on television. Based on the same principles as the experiments Granqvist tried to recreate, their success casts doubt on the swedish team's attempt to replicate.

Read the NATURE report HERE (excerpt) "Persinger, however, takes issue with the Swedish attempts to replicate his work. "They didn't replicate it, not even close," he says.

Read Persinger's response HERE

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