A new study published in the July Psychological Bulletin has provided some support for the ‘Ganzfeld experiment’ said by parapsychologists to show positive evidence for ‘psi’.
The most renowned and certainly the most controversial domain in parapsychology is a procedure for testing telepathy in a form of free-response condition known as Ganzfeld (German for “total
field”). The ganzfeld is a “special type of environment (or the technique for producing it) consisting of homogenous [sic], unpatterned sensory stimulation” to the eyes and ears of the participant, who is usually in “a state of bodily comfort. Traditionally, the ganzfeld is a procedure whereby an agent in one room is required to “psychically communicate” one of four randomly selected picture targets or movie film targets to a perceiver in another room, who is in the ganzfeld condition of homogeneous sensory stimulation. The ganzfeld environment involves setting up an undifferentiated visual field by viewing red light through halved translucent ping-pong balls taped over the perceiver’s eyes. Additionally, an analogous auditory field is produced by listening to stereophonic white or pink hissing noise. As in the free-response design, the perceiver’s mentation is recorded and accessed later in order to facilitate target identification. At this stage of the session, the perceiver ranks from 1 to 4 the four pictures (one target plus three decoys; Rank 1 = “hit”). This condition follows the noise reduction model, which is considered “psi conducive” because it allegedly reduces irrelevant background noise, leaving mainly the psi signal.
According to the new study (full text as PDF: “Meta-Analysis of Free-Response Studies, 1992–2008: Assessing the Noise Reduction Model in Parapsychology“), “the mean effect size value of the ganzfeld database were significantly higher than the mean effect size of the nonganzfeld noise reduction and the standard free-response databases.” They also found that “selected participants (believers in the paranormal, meditators, etc.) had a performance advantage over unselected participants, but only if they were in the ganzfeld condition.”
The linked article also includes a critical response from noted psi skeptic Ray Hyman – who basically says that psi results remain too inconsistent, and metanalyses such as this cannot be trusted because they allow “manipulations of the data” – as well as a response from the authors of the study (Storm, Tressoldi & Di Risio), who argue the irony of Hyman “citing an arbitrarily representative group of four or five parapsychologists” for his claim that psi results remain inconsistent, and note of the meta-analysis manipulation claim that they were “transparent in our procedures and findings, applied standard rules, and did not invent any untoward techniques.” They conclude:
Hyman is convinced of parapsychology’s “persistent inconsistency”, but we maintain that psi is anything but inconsistent. We argue that the meta-analytic results do count for something. It is of paramount importance not to dismiss statistical anomalies as nothing more than numerical oddities; we would hope that on the strength of the peculiarity of the findings in and of themselves, the scientifically inclined will be sufficiently intrigued by the curious nature of psi to want to find out for themselves what that anomaly might actually be.
