Psychophysical effects in double-slit interference patterns: Response to a critique

Abstract

Walleczek & von Stillfried (2019) offered a critique of an experiment we conducted that was designed to explore possible psychophysical influences on interference patterns generated by an optical double-slit system. The critique claimed that one of eight planned tests in that experiment was a false-positive. Based on that claim, they raised doubts about the results of 16 similar experiments that we previously published. After properly adjusting the eight tests for multiple testing, the false-positive claim is found to be unwarranted. In addition, Walleczek & von Stillfried failed to report a true-positive outcome of a secondary planned hypothesis that remained significant after adjustment for multiple testing. We discuss these and other issues in response to the arguments offered in their critique.To date, 11 of 28 published replications of this type of experiment, reported by four independent teams, report statistically significant outcomes. Given the implications of genuine psychophysical effects on our understanding of the role of consciousness in the physical world, we encourage other researchers to replicate this experiment, and we welcome further discussion about experimental methods and theoretical models regarding this line of inquiry.

Response: Commentary: False-Positive Effect in the Radin Double-Slit Experiment on Observer Consciousness as Determined With the Advanced Meta-Experimental Protocol

“…A recent commentary by Radin et al ( 2020 ), as well as an earlier critique (Radin et al, 2019 ), heavily misrepresented the methodology and statistical interpretation of this experiment that was commissioned by the funder ( www.fetzer-franklin-fund.org ) to be performed blindly by Radin. Importantly, data encryption was used in this replication experiment to prevent p-hacking and HARKing, i.e., undisclosed hypothesizing after the results are known (Kerr, 1998 ).…”

“…Here we provide a summary of the two major ways in which Radin et al ( 2019 , 2020 ) deviated from the funder-approved, pre-specified protocol for this commissioned study. For full disclosure and transparency, and given the elaborate construction of the misrepresentation by Radin et al ( 2019 , 2020 ), the detailed research record is available in Walleczek and von Stillfried ( 2020 ).…”

“…Given that the criticisms by Radin et al ( 2019 , 2020 ) are based on HARKing, the results reported in Walleczek and von Stillfried ( 2019 ) remain valid exactly as reported: (i) a “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 (ii) “no statistically significant effects” in those two groups for which true-positives were predicted to occur. These observations are consistent with an independent statistical reanalysis of the Radin double-slit (DS)-experiment by Tremblay ( 2019 ) and a replication attempt by Guerrer ( 2019 ).…”

“…Importantly, the probability of a true discovery is increased greatly if empirical proof is available for the absence of false-positive effects in this experiment. However, Radin et al ( 2019 , 2020 ) do not report a credible control mechanism that would be capable of distinguishing a (potential) true-positive observer effect from a false-positive observer effect. Therefore, the present authors call for the implementation of advanced control-test strategies, like the confirmatory AMP-based research design (Walleczek and von Stillfried, 2019 , 2020 ), for empirically detecting and preventing uncontrolled false-positive effects in the Radin DS-experiment.…”

False-positive Effect in the Radin Double-slit Experiment: HARKing is used by Radin et al. to Misrepresent the Advanced Meta-experimental Protocol used in Walleczek and von Stillfried (2019)

“…For historical overview, Walleczek and von Stillfried (2019) had previously reported (i) the absence of any truepositive 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 (2019Radin et al ( , 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.…”