Prior work by Radin et al. (2012, 2016) reported the astonishing claim that an anomalous effect on double-slit (DS) light-interference intensity had been measured as a function of quantum-based observer consciousness. Given the radical implications, could there exist an alternative explanation, other than an anomalous consciousness effect, such as artefacts including systematic methodological error (SME)? To address this question, a conceptual replication study involving 10,000 test trials was commissioned to be performed blindly by the same investigator who had reported the original results. The commissioned study performed confirmatory and strictly predictive tests with the advanced meta-experimental protocol (AMP), including with systematic negative controls and the concept of the sham-experiment. Whereas the replication study was unable to confirm the original results, the AMP was able to identify an unacceptably low true-negative detection rate with the sham-experiment in the absence of test subjects. The false-positive detection rate reached 50%, whereby the false-positive effect, which would be indistinguishable from the predicted true-positive effect, was significant at p = 0.021 (σ = -2.02; N = 1,250 test trials). The false-positive effect size was about 0.01%, which is within an-order-of-magnitude of the claimed consciousness effect (0.001%; Radin et al., 2016). The false-positive effect, which indicates the presence of significant SME in the Radin DS-experiment, suggests that skepticism should replace optimism concerning the radical claim that an anomalous quantum consciousness effect has been observed in a controlled laboratory setting.
Prior work by Radin et al. (2012, 2016) reported the astonishing claim that an anomalous effect on double-slit (DS) light-interference intensity had been measured as a function of quantum-based observer consciousness. Given the radical implications, could there exist an alternative explanation, other than an anomalous consciousness effect, such as artefacts including systematic methodological error (SME)? To address this question, a conceptual replication study involving 10,000 test trials was commissioned to be performed blindly by the same investigator who had reported the original results. The commissioned study performed confirmatory and strictly predictive tests with the advanced meta-experimental protocol (AMP), including with systematic negative controls and the concept of the sham-experiment. Whereas the replication study was unable to confirm the original results, the AMP was able to identify an unacceptably low true-negative detection rate with the sham-experiment in the absence of test subjects. The false-positive detection rate reached 50%, whereby the false-positive effect, which would be indistinguishable from the predicted true-positive effect, was significant at p = 0.021 (σ = -2.02; N = 1,250 test trials). The false-positive effect size was about 0.01%, which is within an-order-of-magnitude of the claimed consciousness effect (0.001%; Radin et al., 2016). The false-positive effect, which indicates the presence of significant SME in the Radin DS-experiment, suggests that skepticism should replace optimism concerning the radical claim that an anomalous quantum consciousness effect has been observed in a controlled laboratory setting.
A general commentary by Walleczek and von Stillfried (2020) was recently published in Frontiers in Psychology. The present work provides an account of (i) the detailed research record and (ii) the main arguments behind the commentary for the purpose of full transparency and disclosure. For historical overview, Walleczek and von Stillfried (2019) had previously reported (i) the absence of any true-positive effects and (ii) the presence of one false-positive effect in a commissioned replication study of the Radin double-slit (DS) experiment on observer consciousness. In their subsequent misrepresentations, Radin et al. (2019, 2020) regrettably used the malpractice of undisclosed HARKing, i.e., undisclosed hypothesizing after the results are known. HARKing can increase greatly the risk of false-negative or false-positive conclusions. Specifically, Radin et al. (2019, 2020) deviated in two major ways from the pre-specified protocol for this commissioned study, which (i) was agreed to by Radin before data collection was started (Radin, 2011) and (ii) included data encryption to prevent the use of p-hacking and HARKing. First, Radin et al. (2019) violate the original research design by reporting a so-called “true-positive outcome of a secondary planned hypothesis”. Contrary to the claim by Radin et al. (2019, 2020), that hypothesis was not, however, part of the planned test strategy, but, instead, the associated statistical analysis – a chi-square test – was chosen by Radin sometime after the planned statistical analysis had been completed and the data unblinded. Second, Radin et al. (2019, 2020) violate the funder-approved research design in an additional way by falsely claiming that the newly developed protocol, i.e., the advanced meta-experimental protocol (AMP), implements a non-predictive test strategy when – in fact – the AMP-based test strategy is strictly predictive. Put simply, Radin et al. (2019, 2020) are mistaken that the funder-approved hypotheses posited the random occurrence of effects for the test categories in this replication experiment; instead, a different specific prediction was tested in each of the eight planned test categories, and true-positive effects were predicted to occur for only two (12.5%) of the 16 possible measurement outcomes of the eight planned single-test categories. Therefore, in the predictive single-testing regime, a statistical correction for non-predictive, i.e., random, multiple testing would not be appropriate and would thus violate the AMP-based strategy, which was implemented in the commissioned study based upon the planned outcome predictions as pre-specified in Radin (2011). Neither of these post-hoc changes by Radin et al. (on the basis of HARKing) were disclosed in Radin et al. (2019, 2020) and both these changes violate the funder-approved, original methodology agreed upon in Radin (2011) and pre-specified in the research contract. In summary, the present work reconfirms that – exactly as reported in Walleczek and von Stillfried (2019) – “the false-positive effect, which would be indistinguishable from the predicted true-positive effect, was significant at p = 0.021 (σ = −2.02; N = 1,250 test trials)” and “no statistically significant effects could be identified” in those two groups for which true-positives were predicted to occur. These observations are consistent also with an independent statistical reanalysis of the Radin DS-experiment by Tremblay (2019) and a replication attempt by Guerrer (2019). Tremblay reported significant false-positives in control groups and Guerrer found significant effects with post-hoc analyses only, but null results only when using the planned confirmatory analysis. As a general recommendation, the authors call for the implementation of advanced control-test strategies, including novel approaches from the metascience reform movement, for empirically detecting and preventing uncontrolled false-positive effects in parapsychological research.
An experiment was conducted to explore possible psychophysical influences on interference patterns generated by an optical double-slit system. The experiment was motivated by a proposed explanation of the quantum measurement problem by John von Neumann and others, namely that consciousness collapses the quantum wavefunction. The study design generated a single database partitioned into eight differential tests, four in experimental conditions where participants alternately directed their attention toward and away from the optical system, and four in sham conditions when no one was present. The planned analysis was comparison of means in attention-toward vs. attention-away conditions; a secondary analysis added later, but before the data were examined, was comparison of variances. After adjusting the eight mean comparisons for multiple testing, none were statistically significant, but one of the eight variance differences was suggestively significant.To date, 11 of 28 conceptual replications of this experiment, reported by four independent teams, have reported statistically significant outcomes (p < 0.05, two-tail), where only one would be expected by chance. Given the implications of psychophysical effects on our understanding of the role of consciousness in the physical world, we encourage others to attempt to replicate this experiment.
The validity of the assertion that some recent double-slit interference experiments, conducted by Radin et al., would have tested the possible role of the experimenter's mind in the collapse of the quantum wave function, is questioned. It is emphasized that quantum mechanics doesn't need any psychophysical ingredient to explain the measurement processes, and therefore parapsychologists shouldn't resort to the latter to support the possibility of psychokinesis, but search for more convincing explanations.
Lay Summary Whether and how consciousness could affect a physical system is a fundamental question. Radin et al (Radin et al 2012, 2013) reported that consciousness could perturb the fringe pattern of the classical experiment of double-slit illuminated by a laser beam. In understanding the possible physical cause to the observed change of the fringe, Radin et al modeled that the light intensity passing a slit subjected to consciousness intention could have changed. By using computer simulation based on standard wave approaches to light, we demonstrate that the extent of the change to the double-slit fringe as reported by Radin et al can be caused by a spectral perturbation to the light, which would take only approximately times of the energy change pertinent to the intensity change as was modeled by Radin et al. This indicates that the intensity change as modeled was unlikely the physical precursor to the observed effect. Scientific Abstract Significance: Recent reports [Radin 2012, Radin 2013] on variations to the fringe visibility of the interference patterns of laser-engaged double-slit experiments that seemed inexplicable at the absence of psychophysical influences have elicited notable debates within the scientific community and substantial interest in the lay population. In accounting for the observed changes of fringe pattern, Radin et al. modeled that the electrical field of the light passing the two slits might have reached an asymmetry of 3:1 in comparison to the generally symmetric baseline. However, a change to the double-slit interference fringe could have multiple causes. Identifying the most plausible cause to the fringe-pattern changes as were reported is fundamental to the understanding of the nature of psychophysical effect should it exist. Aim: To theorize an alternative interpretation to the fringe pattern changes of the double-slit interference that could be substantially more plausible than the one conjectured by Radin et al. Approach: We implement computer simulations of double-slit fringe pattern based on the Huygens-Fresnel principle using the primary experimental geometrical parameters of Radin et al. to assess how an asymmetry of the double-slit configuration could affect the fringe visibility. Specifically, we assess how an asymmetry in the physical size properties (slit-width and the lateral offset of the slit-center) and the photonic/spectral properties (intensity, wavelength, and spectral bandwidth) between the two slits would affect the fringe pattern. Fourier transformation of the double-slit interference fringe is also conducted when prompted to infer differences between fringe patterns that may be grossly equivocal in terms of the fringe visibility. Results: The main result is that the normalized interference fringe corresponding to the asymmetry of the electrical field of 3/1 or 1/3:1 is grossly indifferent from that caused by an asymmetry of the spectral bandwidth of 0.00205nm between the two slits at 6328nm center wavelength. A spectral broadening of 0.00205nm centered at 632.8nm would take approximately times of the energy of reducing the electrical field of light of that slit to 1/3 to reach a 3:1 inter-slit ratio of the electrical field. This 0.00205nm spectral broadening of the light could be associated with an energy change of no more than 10 picowatts for the experimental setting utilized by Radin et al. Conclusions: A change to the fringe pattern in the double-slit of Radin et al that was fitted with a 3:1 asymmetry of the electrical field between the two slits could be modeled alternatively by an asymmetry of ~0.00205nm in the spectral bandwidth between the two slits. The latter one, which would take approximately times of the energy-change of the former one to happen, could be substantially more plausible than the former one in acting as the physical precursor to the deviation of the double-slit fringe from the baseline pattern as reported by Radin et al.
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.
An experiment we conducted from 2012 to 2013, which had not been previously reported, was designed to explore possible psychophysical effects resulting from the interaction of a human mind with a quantum system. Participants focused their attention toward or away from the slits in a double-slit optical system to see if the interference pattern would be affected. Data were collected from 25 people in individual half-hour sessions; each person repeated the test ten times for a total of 250 planned sessions. “Sham” sessions designed to mimic the experimental sessions without observers present were run immediately before and after as controls. Based on the planned analysis, no evidence for a psychophysical effect was found. Because this experiment differed in two essential ways from similar, previously reported double-slit experiments, two exploratory analyses were developed, one based on a simple spectral analysis of the interference pattern and the other based on fringe visibility. For the experimental data, the outcome supported a pattern of results predicted by a causal psychophysical effect, with the spectral metric resulting in a 3.4 sigma effect (p = 0.0003), and the fringe visibility metric resulting in 7 of 22 fringes tested above 2.3 sigma after adjustment for type I error inflation, with one of those fringes at 4.3 sigma above chance (p = 0.00001). The same analyses applied to the sham data showed uniformly null outcomes. Other analyses exploring the potential that these results were due to mundane artifacts, such as fluctuations in temperature or vibration, showed no evidence of such influences. Future studies using the same protocols and analytical methods will be required to determine if these exploratory results are idiosyncratic or reflect a genuine psychophysical influence.