Stage 2 Registered Report: Anomalous Perception in a Ganzfeld Condition - A Meta-Analysis of More Than 40 Years Investigation

For over four decades, parapsychology researchers have been running a peculiar experiment: put someone in a state of sensory deprivation called the ganzfeld (think halved ping-pong balls over the eyes, white noise in headphones, red light) and see if a distant sender can mentally transmit an image to them. This registered report — meaning the analysis plan was locked in before the authors touched the data, a gold-standard practice for preventing bias — gathered 78 of these studies spanning 1974 to 2020. The bottom line: participants picked the correct target image about 31% of the time when pure chance would predict 25%. That six-percentage-point bump may sound modest, but the statistics backing it up are genuinely impressive. The Bayes factor was 89.5, meaning the data is roughly 90 times more likely if the effect is real than if it is just noise. Both traditional and Bayesian statistical models agreed on an effect size of about 0.08 — small but stubbornly consistent. The authors threw four different publication bias tests at the data to check whether the result might just reflect journals only publishing positive findings. All four suggested the effect holds up. A cumulative analysis showed the effect has been remarkably stable since about 1997 — no sign of it fading away over time. Some people appear to be better at this than others.

Pre-selected participants (often people who score high on certain personality traits or have prior experience) produced an effect of 0.13, roughly triple that of unselected volunteers. Telepathy-style tasks, where a real person actively sends the image, outperformed clairvoyance tasks where no sender is involved. The catch? The effect is small enough that you would need around 245 trials for an 80% chance of detecting it in a single experiment, and there is still unexplained variation between studies. One of three peer reviewers, a neuroscientist, declined to approve the report, while two others — including parapsychology researcher Dean Radin — gave it the green light.