Anomalous “Retrocausal” Effects on Performance in a Go/NoGo Task

How the experiment worked

Participants first responded to two shapes and withheld their responses to two others. Afterwards, one of the first two shapes was randomly selected for further practice. The researchers compared the earlier response times for the shape later practised with those for the other shape. A questionnaire assessed rational and intuitive thinking styles, while a separate baseline task measured reaction speed.

The reported result

The analysis included 67 participants. Earlier responses were faster, on average, to the shape that would later receive further practice. The strongest statistical evidence appeared in the 35 participants classified as intuitive thinkers: the results section reports p = 0.001, one-tailed. The rational-thinking group did not show a statistically significant difference. These are results reported by the study, not a demonstrated mechanism for information travelling backwards in time.

Analysis choices and interpretation

The paper checks whether shape difficulty or unequal shape frequencies could account for the pattern. It also reports an independent review of the original research plan. That review found ambiguities, including unspecified reaction-time normalisation and an incompletely defined thinking-style measure. The authors state that the findings should be interpreted in light of those shortcomings.

The study therefore connects an unusual experimental question with a practical methodological one: how precisely must researchers document their predictions and analysis choices? Independent, preregistered replication would help establish whether the reported pattern is robust. The earlier 2013 conference paper describes the same experiment and should not be counted as a separate replication.