(2017-09-21, 03:13 AM)malf Wrote: Are you saying these studies represent strong (albeit very dry) evidence for psi? No, I wasn't expressing an opinion - just posting the abstracts for reference. I'm still thinking about the new study by Guerrer, and was planning to read through this earlier work. I'll probably post some more notes as I do in case they're useful to anyone. (2017-09-20, 08:22 PM)Chris Wrote: And here is an earlier paper which was the first to use a double-slit in parapsychological research: A few years later Jeffers (who had been responsible for the York University experiments reported in the joint paper with Ibison) contributed a chapter to "Psi Wars", edited by James E. Alcock, Jean Burns and Anthony Freeman (2004). The chapter is much more sceptical in tone than the joint paper. Most of it can be read in a Google Preview here: https://books.google.com/books?id=JyfbUv...&lpg=PA135 The part relating to the double-slit experiment (pp. 146, 147) is: [Image: Jeffers_146.jpg] [Image: Jeffers_147.jpg] (The paper by Mathews - actually Matthews - is a general discussion of the use of p values, with no specific reference to this experiment: https://www.scientificexploration.org/do...tthews.pdf) James Alcock also refers to this experiment in his own chapter of the same book: https://books.google.com/books?id=JyfbUv...9&lpg=PA29 The relevant section (pp. 36, 37) is: [Image: Alcock_36.jpg] [Image: Alcock_37a.jpg] [Image: Alcock_37b.jpg]
I'll just post a few notes on the Ibison and Jeffers paper from 1998. It reports two double-slit experiments using the same apparatus, the first done by Jeffers at York University, Ontario, and the second by Ibison at the PEAR Lab at Princeton. The slits were illuminated for one second out of every three (a trial), and an experimental series consisted of 41 alternating runs of 11 active or 10 inactive trials. In the active trials, the participant attempted to influence the interference pattern, and in the inactive trials s/he didn't.
The contrast in the interference pattern was characterised by a variable calculated from the central peak height H1 and the average of the two neighbouring peak heights H2, after the subtraction of background levels. Peak height was estimated using a local quadratic fit. The contrast variable was equal to (H1-H2)/(H1+H2). The feedback differed slightly in the two experiments. In both, after each trial the interference pattern was displayed together with a bar whose height represented the value of the contrast variable. At York, the participants "were advised to imagine that during the active runs they could identify (by extra-sensory means) the path of the light beam near to the double slit. They were told that success at this task would be reflected in a less-well-defined interference pattern, and a corresponding reduction in the contrast reported by the analogue indicator." At Princeton they "were told that their primary task was to intend the analogue indicator bar to remain as low as possible", though it was also explained that the experiment "was designed to measure anomalous wave-function collapse". A Z value for each series was calculated as (if I understand correctly), the average difference in contrast between each active run and the neighbouring inactive runs, divided by a variance derived from the differences between (neighouring pairs of?) inactive runs. At York, the number of series wasn't specified in advance, but after 74 series the combined Z value was insignificant at Z=-0.481. However, a secondary analysis found that the variance of the Z values for the different series was larger than expected by chance (p=0.013). At Princeton the number of series was pre-set at 20, and the combined Z value was 1.654, which was just significant at p=0.05.
A couple of further comments. The results of Jeffers's experiment had previously been reported at a conference in 1996. According to the paper by Ibison and Jeffers, unfortunately the active and inactive results had been transposed, so the non-significant result presented at the conference related to the runs when the participants hadn't been trying to influence the interference pattern (!). But it turned out that the same was true of the active sessions.
It seems odd that Alcock emphasised that he had vetted the experimental design, considering that Jeffers didn't even fix the number of sessions in advance. I suspect Alcock would have been less lenient towards such a serious flaw in design if the result had been different. It's also a bit unsatisfactory that neither Alcock nor Jeffers (in "Psi Wars") mentions the odd result about the larger-than-expected variance of the York data. Again, it's difficult to imagine Alcock would have ignored it if Jeffers's main result had been positive. The paper says "the same tests reveal no such anomaly in the control data". But as the control data at York weren't structured in the same way as the participant data - but just came from a single sequence of 350 trials - it's not even obvious how the same tests would be applied to the control data.
Here's another paper reporting an independent re-analysis of some of the data from paper (2) by Radin et al.
https://www.researchgate.net/publication...ce_pattern Independent verification of psychophysical interactions with a double-slit interference pattern Wolfgang Baer Physics Essays 28(1), 47-54 (2016) Approximately 50 GB of data from interference patterns from double slit experiments suggesting psychophysical interactions recently reported in this journal [Radin et al., Phys. Essays 26, 4 (2013)] were independently analyzed at our Nascent Systems Inc. (NSI) facilities. The method of analysis sought to avoid complex statistical analysis as much as possible and look for simple correlations between mental efforts by participants and directly observable effects on the photon counts of minima seen in the interference patterns. The mean and standard deviation of the normalized percent difference counts between mental concentration and relaxation periods in 1435 trial files analyzed was 0.00185% and 0.0574, respectively. The same difference effect in control data generated by Robots with no Human involved was - 0.000475% and 0.06, respectively. These analyses of the interference pattern showed a small but consistent bias that indicates human thought interaction with material may be measurable and real. However, physical noise in the system is too high to justify such conclusions. In addition, a speculative outline of a psychophysical theory is provided that suggests specific instructions designed to guide the mental concentration, which may amplify the physical interference effect in future experiments. Before concluding that a psychophysical effect has been measured by these experiments, it is recommended that experiments using a substantially lower noise power supply, timing control, and instructions based on applicable quantum interpretations be conducted. This paper also refers to a draft paper: D. Radin, L. Michel, J. Johnston, A. Delorme, "Effect of focused attention on fringe visibility in a double-slit optical interferometer" But apparently it never appeared in that form.
I had been planning to try to post a summary of Dean Radin's double-slit studies, in case anyone was interested, but having finally got through the four papers I think I'm going to admit defeat.
Between them, the papers cover 16 experiments, done using four pieces of apparatus, and analysed using (approximately) half a dozen different methods. If these experiments were showing a consistent effect it might be worth spending the time to work out all the details, but a lot of them don't show significant results, and for those that do, the direction of the effect isn't always the same. The experiment with the largest effect size (a whopping 0.90) shows the interference pattern strengthening when the subjects direct their attention towards it - contrary to the hypothesis and to most of the other significant results. The problem is that the percentage change in the strength of the pattern is tiny - something like 0.001% - and the signal is vulnerable to environmental factors such as temperature. These experiments need to be very carefully designed to minimise such effects, and I'm not convinced enough has always been done in this respect. My impression is that the new study by Gabriel Guerrer goes to greater lengths to exclude artefacts. 
(2017-10-19, 07:27 PM)Chris Wrote: If these experiments were showing a consistent effect it might be worth spending the time to work out all the details, but a lot of them don't show significant results, and for those that do, the direction of the effect isn't always the same. (Underlining mine) That's curious, Chris: there's no indication of that at all in the four abstracts you posted on page one of this thread - one would have gotten the impression from those abstracts that all the tests produced highly significant results. Thanks for taking the time to read through these papers and offer your summary (I haven't read any of the papers yet myself). (2017-10-20, 02:09 AM)Laird Wrote: That's curious, Chris: there's no indication of that at all in the four abstracts you posted on page one of this thread - one would have gotten the impression from those abstracts that all the tests produced highly significant results. It is there in the abstract of the 2015 paper, which says "Overall the experiments found evidence supportive of an interaction that appears to “steer” the wavefunction to either reduce or to sharpen interference fringes." [my emphasis] But what you might not guess from that is that the feedback during all the experiments was meant to encourage the reduction of the interference pattern. In another experiment, the interference pattern was also strengthened (the 2014 section of the online experiment, reported in the 2016 paper), but it was discovered that owing to a programming error, the feedback in that case had been encouraging the strengthening of the pattern. In the 2013 section of the online experiment, though most features indicated a weakening of the pattern, the height of the peaks in intensity increased, which again was contrary to expectation. This is quite important if one takes seriously the interpretation that what's happening is a kind of psychical observation of the photons, because (if I understand correctly) the idea is that that should always weaken the interference pattern. But another unsatisfactory aspect of these studies is that the participants don't seem to have been given very clear guidance of what they were meant to be doing. For example, the original 2012 paper says they were told to "direct their attention" to the slits, but "If the task was still unclear, it was suggested that they could try to mentally block one of the slits, or to ‘‘become one with’’ the optical system in a contemplative way, or to mentally push the laser beam to cause it to go through one of the two slits rather than both." Unfortunately (again if I understand correctly) the blocking or pushing, unlike observation, could either strengthen or weaken the interference pattern, depending on which slit was favoured.
Courtesy of the SPR Facebook page, here's a post by Dean Radin a couple of days ago (I would have linked rather than copying the text, but Facebook doesn't allow non-users to share):
This talk from 2016 is approaching a million views. Updates on this line of work include (a) replications from physicist Gabriel Guerrer, who has an article on this work presently under review by a journal, and (b) an independent reanalysis of two years of data from our online double-slit experiment by a French physicist, which is also under review by a journal. In both cases, they report anomalies in alignment with what we've been observing, namely that something unexpected (according to conventional expectations) is going on in these experiments that appears to be associated with conscious intention. We've since built a new double-slit system and are continuing these experiments. We're using what we hope is a more sensitive way to detect the effect. We've completed the first experiment with very good results, but as always, we'll gain confidence only if we see further successful replications. So further experiments will be underway soon (all in the lab, no online experiments are planned for now). https://youtu.be/nRSBaq3vAeY https://www.facebook.com/pg/DeanRadinsPage/ I find it a bit odd that Gabriel Guerrer's work is claimed as a replication (unless the paper being considered by a journal is radically different from the preprint that's available online). (2017-10-19, 07:27 PM)Chris Wrote: Between them, the papers cover 16 experiments, done using four pieces of apparatus, and analysed using (approximately) half a dozen different methods. It seems there is now a new piece of apparatus, and another new way to detect the effect. (2019-01-12, 08:38 AM)Chris Wrote: Courtesy of the SPR Facebook page, here's a post by Dean Radin a couple of days ago (I would have linked rather than copying the text, but Facebook doesn't allow non-users to share): Again courtesy of the SPR Facebook page, here is the independent reanalysis that Dean Radin was referring to, published in PLoS ONE: Independent re-analysis of alleged mind-matter interaction in double-slit experimental data Nicolas Tremblay Abstract: A two year long experimental dataset in which authors of Radin, et al., 2016 claim to find evidence of mind-matter interaction is independently re-analyzed. In this experiment, participants are asked to periodically shift their attention towards or away from a double-slit optical apparatus. Shifts in fringe visibility of the interference pattern are monitored and tested against the common sense null hypothesis that such shifts should not correlate with the participant’s attention state. We propose a deeper analysis of the dataset, identifying all the necessary arbitrary pre-analysis choices one needs to make, and carefully assessing the results’ robustness regarding these choices. Results are twofold. Firstly, even with a conservative correction for the multiple statistical tests the analysis calls for, we confirm the existence of significant although small anomalies in the direction predicted by the mind-matter interaction hypothesis. On the other hand, and unlike Radin, et al., 2016, we also report significant although even smaller anomalies in the control dataset. This leads us to conclude that this particular dataset does not provide strong evidence of mind-matter interaction, yet certainly contains inexplicable anomalies that should motivate replication attempts in highly controlled environments. https://journals.plos.org/plosone/articl...ne.0211511 In fact it seems the author found significant results in the predicted direction in only one of the two datasets. In the other, two statistical tests were applied. One of them showed significant deviations from expectation, but in the direction opposite to that predicted. |
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