"Deep into that darkness peering, long I stood there, wondering, fearing, doubting, dreaming dreams no mortal ever dared to dream before..."
(2017-08-25, 06:42 PM)E. Flowers Wrote: I found it... It's discussed in retro-Skeptiko #89: http://skeptiko.com/michael-persinger-di...thic-link/
Thanks - I didn't have that one.
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(2017-08-25, 05:59 PM)Chris Wrote: I have noted various references to similar work, though I haven't had a chance to follow them up (I can't see Persinger in my notes). Some are discussed in the "Unconscious Psi" chapter of Dean Radin's book "Entangled Minds". One of them, by Wackermann et al. (2003), is available online here:
https://www.researchgate.net/publication...n_subjects
I have been looking at that Wackermann et al. paper, though I haven't really absorbed it all.
It seems to me there may be some pretty serious problems with the statistical analysis. If anyone has an interest in statistics, I'd be interested to know what they think (particularly if they're familiar with the kind of non-parametric test used in this paper).
(2017-08-26, 08:40 AM)Chris Wrote: I have been looking at that Wackermann et al. paper, though I haven't really absorbed it all.
It seems to me there may be some pretty serious problems with the statistical analysis. If anyone has an interest in statistics, I'd be interested to know what they think (particularly if they're familiar with the kind of non-parametric test used in this paper).
It may be that people aren't interested in this level of technical detail, but I'll carry on, on the basis that it can't do any harm and people can just ignore the posts if they want to.
I still haven't absorbed it all, but at the moment two things concern me about this paper:
(1) Evidently the previous studies (like the one by Kittenis et al.) had suggested that when the "senders" who were shown the visual stimulus exhibited an increase in the EEG signal, the "receivers" in the other room should also show an increase. But Wackermann et al. use a statistical test which indicates whether there are more instances than would be expected by chance of the receivers' signals being either higher or lower than they are in the absence of stimulation. I think it would have been natural to test (at least initially) just whether the signal was higher than normal. I'm not clear whether this was tried and failed, or what. The authors acknowledge that the lack of directionality (and the lack of localisation in the brain of the receivers) is counter-intuitive and "suggestive of an erratic artefact".
(2) The statistical test indicates whether the number of "outliers" (unusually high or low EEG signals) in the receivers, coinciding with the peak EEG response from the senders following stimulation, is larger than would be expected by chance. The number of outliers is calculated for 42 measurement sites, from 6 scalp locations on each of 7 subjects in each of 3 experimental groups (related pairs, unrelated pairs, and controls). I'm not familiar with the statistical test used, but I think it must assume that the measurements at these 42 sites are all independent. I'm open to correction on that point, but surely it can't be assumed that measurements made at 6 scalp locations on the same subject are independent of one another. Dependence would tend to reduce the statistical significance indicated by the test.
Just to add - the formulation of the statistical test is quite complicated, and I don't see any indication that it was fixed in advance of the experiment. On the other hand, the graphs suggest quite a dramatic difference, particularly between the related pairs and the controls (for the related pairs, for about 19% of the measurement sites, more than three quarters of the measurements were found to be outliers, while for the controls the fraction of outliers didn't rise above one third for any of the measurement sites). I find it difficult to believe that difference can be accounted for either by decisions made about the form of the statistical test, or by non-independence of different measurement sites on the same subject. But obviously, if the statistical analysis is flawed, the p-value of 0.01 can't be relied on.
(2017-08-25, 06:42 PM)E. Flowers Wrote: I found it... It's discussed in retro-Skeptiko #89: http://skeptiko.com/michael-persinger-di...thic-link/
I listened to the interview, but unfortunately the discussion of Persinger's own research got squeezed into literally two or three minutes at the end.
But I see that his work in this area is mentioned (together with a lot of related work by others) in the chapter of "Handbook for the 21st Century" by Dean Radin and Alan Pierce. These papers are cited there, and are all available online:
B. T. Dotta, B. P. Mulligan, M. D. Hunter and M. A. Persinger
Evidence of macroscopic quantum entanglement during double quantitative electroencephalographic measurements of friends vs strangers
NeuroQuantology 7, 548-551 (2009)
https://www.neuroquantology.com/index.ph...e/view/251
M. A. Persinger, E. W. Tsang, J. N. Booth and S. A. Koren
Enhanced power within a predicted narrow band of theta activity during stimulation of another by circumcerebral weak magnetic fields after weekly spatial proximity: Evidence of macroscopic quantum entanglement?
NeuroQuantology 6, 7-21 (2008)
https://www.neuroquantology.com/index.ph...e/view/151
M. A., K. S. Saroka, C. F. Lavallee, J. N. Booth, M. D. Hunter, B. P. Mulligan, S. A. Koren, H.-P. Wu, Noa Gang
Correlated cerebral events between physically and sensory isolated pairs of subjects exposed to yoked circumcerebral magnetic fields.
Neuroscience Letters 486(3), 231-234 (2010)
https://www.researchgate.net/publication...tic_fields
[NB NeuroQuantology has been accused by sceptics of being a pseudoscience journal.]
(2017-08-26, 05:04 PM)Chris Wrote: It may be that people aren't interested in this level of technical detail, but I'll carry on, on the basis that it can't do any harm and people can just ignore the posts if they want to.
I still haven't absorbed it all, but at the moment two things concern me about this paper:
(1) Evidently the previous studies (like the one by Kittenis et al.) had suggested that when the "senders" who were shown the visual stimulus exhibited an increase in the EEG signal, the "receivers" in the other room should also show an increase. But Wackermann et al. use a statistical test which indicates whether there are more instances than would be expected by chance of the receivers' signals being either higher or lower than they are in the absence of stimulation. I think it would have been natural to test (at least initially) just whether the signal was higher than normal. I'm not clear whether this was tried and failed, or what. The authors acknowledge that the lack of directionality (and the lack of localisation in the brain of the receivers) is counter-intuitive and "suggestive of an erratic artefact".
(2) The statistical test indicates whether the number of "outliers" (unusually high or low EEG signals) in the receivers, coinciding with the peak EEG response from the senders following stimulation, is larger than would be expected by chance. The number of outliers is calculated for 42 measurement sites, from 6 scalp locations on each of 7 subjects in each of 3 experimental groups (related pairs, unrelated pairs, and controls). I'm not familiar with the statistical test used, but I think it must assume that the measurements at these 42 sites are all independent. I'm open to correction on that point, but surely it can't be assumed that measurements made at 6 scalp locations on the same subject are independent of one another. Dependence would tend to reduce the statistical significance indicated by the test.
Just to add - the formulation of the statistical test is quite complicated, and I don't see any indication that it was fixed in advance of the experiment. On the other hand, the graphs suggest quite a dramatic difference, particularly between the related pairs and the controls (for the related pairs, for about 19% of the measurement sites, more than three quarters of the measurements were found to be outliers, while for the controls the fraction of outliers didn't rise above one third for any of the measurement sites). I find it difficult to believe that difference can be accounted for either by decisions made about the form of the statistical test, or by non-independence of different measurement sites on the same subject. But obviously, if the statistical analysis is flawed, the p-value of 0.01 can't be relied on.
Again, looking at the chapter by Radin and Pierce in the 21st Century Handbook (and the chapter by Richard Broughton, which covers some of the same ground), it seems that Wackermann et al. went on to modify their technique, and presented further results at the 47th Annual Convention of the Parapsychological Association in 2004.
But then in 2008 Ambach tried an exact replication, and found serious problems with the previous statistical analysis (including the lack of independence that worried me), which tended to increase the apparent statistical significance of the results. Ambach's results weren't significant, and Wackermann responded, emphasising that it was doubtful whether there was any real effect there.
Ambach's and Wackermann's papers were published in the European Journal of Parapsychology 23 (2), which is available here:
http://ejp.naturalresourceswellbeing.com...0v23-2.pdf
(2017-08-26, 05:04 PM)Chris Wrote: It may be that people aren't interested in this level of technical detail, but I'll carry on, on the basis that it can't do any harm and people can just ignore the posts if they want to.
I still haven't absorbed it all, but at the moment two things concern me about this paper:
(1) Evidently the previous studies (like the one by Kittenis et al.) had suggested that when the "senders" who were shown the visual stimulus exhibited an increase in the EEG signal, the "receivers" in the other room should also show an increase. But Wackermann et al. use a statistical test which indicates whether there are more instances than would be expected by chance of the receivers' signals being either higher or lower than they are in the absence of stimulation. I think it would have been natural to test (at least initially) just whether the signal was higher than normal. I'm not clear whether this was tried and failed, or what. The authors acknowledge that the lack of directionality (and the lack of localisation in the brain of the receivers) is counter-intuitive and "suggestive of an erratic artefact".
In a later review of the field (Mind and Matter 2(1), 105-122 (2004)), Wackermann says the effect could be obtained only by counting both high and low outliers (p. 115):
http://www.mindmatter.de/resources/pdf/wackermann.pdf
Much as I dislike the sceptical mantra of "p-hacking", it doesn't seem too unfair to apply it to this 2003 paper. In Wackermann's 2004 review, he seems to have a pretty low opinion of the quality of most of the similar work published to that date. And at the end of his 2008 response to Ambach, he explains why he is abandoning work on "the search for so-called ‘physiological signs of psi’" (in which he includes presentiment):
"As to our knowledge, none of those high hopes has ever been fullfilled, and none of those approaches developed into a really working experimental paradigm — that is, one yielding reproducible results across laboratories, results that would visibly stand out of the bush of error bars. There are no signs of real progress. May each individual researcher draw her/his conclusions from this observation. We take the lesson seriously and turn to more productive research topics, not to spend our lives in a heroically ‘relentless’ but ultimately unproductive search."
(2017-08-22, 10:36 PM)Chris Wrote: I'm not very clear about what the authors did next after this study. I can't find any more published papers by them along the same lines, but there's an abstract of Kittenis's thesis (degree awarded 2008) here:
http://ethos.bl.uk/OrderDetails.do?did=1...hos.653483
It refers to two studies which showed significant effects, but then mentions a third study in which "a variation of the experimental paradigm was adopted in order to increase the overall sample size", and says no effect was found in that study. But what the variation of the experimental paradigm was, I don't know.
I'm told that Kittenis's thesis is due to be scanned and uploaded to the Edinburgh Research Archive in the next few months:
https://www.era.lib.ed.ac.uk/
I'd guess the same may be true of some other psi-related Edinburgh theses.
(2017-08-27, 07:52 AM)Chris Wrote: I listened to the interview, but unfortunately the discussion of Persinger's own research got squeezed into literally two or three minutes at the end.
But I see that his work in this area is mentioned (together with a lot of related work by others) in the chapter of "Handbook for the 21st Century" by Dean Radin and Alan Pierce. These papers are cited there, and are all available online:
B. T. Dotta, B. P. Mulligan, M. D. Hunter and M. A. Persinger
Evidence of macroscopic quantum entanglement during double quantitative electroencephalographic measurements of friends vs strangers
NeuroQuantology 7, 548-551 (2009)
https://www.neuroquantology.com/index.ph...e/view/251
M. A. Persinger, E. W. Tsang, J. N. Booth and S. A. Koren
Enhanced power within a predicted narrow band of theta activity during stimulation of another by circumcerebral weak magnetic fields after weekly spatial proximity: Evidence of macroscopic quantum entanglement?
NeuroQuantology 6, 7-21 (2008)
https://www.neuroquantology.com/index.ph...e/view/151
M. A., K. S. Saroka, C. F. Lavallee, J. N. Booth, M. D. Hunter, B. P. Mulligan, S. A. Koren, H.-P. Wu, Noa Gang
Correlated cerebral events between physically and sensory isolated pairs of subjects exposed to yoked circumcerebral magnetic fields.
Neuroscience Letters 486(3), 231-234 (2010)
https://www.researchgate.net/publication...tic_fields
[NB NeuroQuantology has been accused by sceptics of being a pseudoscience journal.]
Continuing my ramble through the papers in this field - which I had been meaning to look at for ages, but wouldn't have got round to without the impetus from the new forum - I read the third of these papers by Persinger and collaborators.
The idea that you can bring two brains "into synch" by subjecting them both to an identical time-varying magnetic field is interesting - particularly as Kittenis's protocol involved playing two people identical soundtracks - but I have to say I found this the least convincing study I've looked at so far (including the Wackermann one which was later shown to be essentially flawed).
For one thing, I didn't think there were sufficient control measurements to eliminate the possibility that the observed effects were produced normally (though if they were, I suppose the results would have been more impressive). But more seriously, there seemed to be tremendous scope for trying mulitiple hypotheses to find one that worked. There were different configurations of the magnetic fields that were applied (up to 6), different frequencies for the optical stimuli (up to 4) and different EEG measurement sites (up to 4). Three experiments were reported, and in each one the significant results were found under a different and quite limited selection of conditions.
It's fair enough that an effect may manifest itself only within a limited range of conditions, but if that range has to be different every time, people are going to get suspicious. Obviously what needs to be done is to confirm the effect with further subjects, with the conditions fixed beforehand. Judging by this paper, that hadn't been done by 2010, and a search for further work doesn't suggest it's been done since then.
(2017-08-27, 07:52 AM)Chris Wrote: I listened to the interview, but unfortunately the discussion of Persinger's own research got squeezed into literally two or three minutes at the end.
Try this one on the follow-up, it's short but straight to the point: https://jcer.com/index.php/jcj/article/viewFile/499/521
"Deep into that darkness peering, long I stood there, wondering, fearing, doubting, dreaming dreams no mortal ever dared to dream before..."
(This post was last modified: 2017-08-29, 05:50 PM by E. Flowers.)
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