Editing Parapsychology (section)

====Ganzfeld====
{{Main| Ganzfeld experiment}}
The [[Ganzfeld experiment|Ganzfeld]] ([[German language|German]] for "whole field") is a technique used to test individuals for telepathy. The technique—a form of moderate [[sensory deprivation]]—was developed to quickly quiet mental "noise" by providing mild, unpatterned stimuli to the [[visual]] and [[Auditory system|auditory]] senses. The visual sense is usually isolated by creating a soft red glow which is diffused through half [[ping-pong ball]]s placed over the recipient's eyes. The auditory sense is usually blocked by playing [[white noise]], static, or similar sounds to the recipient. The subject is also seated in a reclined, comfortable position to minimize the sense of touch.<ref name="Radin2007">{{Cite book| title=The Conscious Universe: The Scientific Truth of Psychic Phenomena | author=Dean I. Radin | publisher= HarperOne | isbn=978-0062515025 | ref=ConsciousUniverse | year=1997}}</ref>

In the typical Ganzfeld experiment, a "sender" and a "receiver" are isolated.<ref name="HymanGanzfeld">{{Cite journal | author = Hyman, Ray |author-link=Ray Hyman| year = 1985 | title = The Ganzfeld Psi Experiments: A Critical Appraisal | journal = Journal of Parapsychology | volume = 49 }}</ref> The receiver is put into the Ganzfeld state,<ref name="Radin2007"/> or [[Ganzfeld effect]] and the sender is shown a video clip or still picture and asked to send that image to the receiver mentally. While in the Ganzfeld, experimenters ask the receiver to continuously speak aloud all mental processes, including images, thoughts, and feelings. At the end of the sending period, typically about 20 to 40 minutes, the receiver is taken out of the Ganzfeld state and shown four images or videos, one of which is the actual target and three non-target decoys. The receiver attempts to select the target, using perceptions experienced during the Ganzfeld state as clues to what the mentally "sent" image might have been.

[[File:Ganzfeld.jpg|thumb|left|Participant of a [[Ganzfeld experiment]]. Proponents say such experiments have shown evidence of telepathy,<ref name=PsychologicalBulletin2/> while critics like [[Ray Hyman]] have pointed out that they have not been independently replicated.<ref name=PsychologicalBulletin1/>]]
The Ganzfeld experiment studies that were examined by [[Ray Hyman]] and [[Charles Honorton]] had methodological problems that were well documented. Honorton reported only 36% of the studies used duplicate target sets of pictures to avoid handling cues.<ref>Julie Milton, [[Richard Wiseman]]. (2002). ''A Response to Storm and Ertel (2002)''. The Journal of Parapsychology. Volume 66: 183–186.</ref> Hyman discovered flaws in all of the 42 Ganzfeld experiments, and to assess each experiment, he devised a set of 12 categories of flaws. Six of these concerned statistical defects, and the other six covered procedural flaws such as inadequate [[documentation]], randomization, security, and possibilities of sensory leakage.<ref name="Hyman2007"/> Over half of the studies failed to safeguard against [[sensory leakage]], and all of the studies contained at least one of the 12 flaws. Because of the flaws, Honorton agreed with Hyman the 42 Ganzfeld studies could not support the claim for the existence of psi.<ref name="Hyman2007"/>

Possibilities of sensory leakage in the Ganzfeld experiments included the receivers hearing what was going on in the sender's room next door as the rooms were not soundproof and the sender's fingerprints to be visible on the target object for the receiver to see.<ref>[[Richard Wiseman]], Matthew Smith, Diana Kornbrot. (1996). ''Assessing possible sender-to-experimenter acoustic leakage in the PRL autoganzfeld''. Journal of Parapsychology. Volume 60: 97–128.</ref><ref>{{cite web|url=http://www.skepdic.com/ganzfeld.html |title=ganzfeld – The Skeptic's Dictionary |publisher=Skepdic.com |date=2011-12-27 |access-date=2014-04-11}}</ref> Hyman reviewed the autoganzfeld experiments and discovered a pattern in the data that implied a visual cue may have taken place. Hyman wrote the autoganzfeld experiments were flawed because they did not preclude the possibility of sensory leakage.<ref name="Hyman2007"/>

In 2010, Lance Storm, Patrizio Tressoldi, and Lorenzo Di Risio analyzed 29 Ganzfeld studies from 1997 to 2008. Of the 1,498 trials, 483 produced hits, corresponding to a hit rate of 32.2%. This hit rate is [[Statistical significance|statistically significant]] with {{nowrap|p < .001.}} Participants selected for personality traits and personal characteristics thought to be psi-conducive were found to perform significantly better than unselected participants in the Ganzfeld condition.<ref name=StormEtAl2010>{{cite journal |url=http://www.psy.unipd.it/~tressold/cmssimple/uploads/includes/MetaFreeResp010.pdf |journal=Psychological Bulletin |date=July 2010 |title=Meta-Analysis of Free-Response Studies, 1992–2008: Assessing the Noise Reduction Model in Parapsychology |author=Lance Storm |author2=Patrizio E. Tressoldi |author3=Lorenzo Di Risio |volume=136 |issue=4 |pages=471–85 |access-date=2010-08-18 |pmid=20565164 |doi=10.1037/a0019457 |url-status=dead |archive-url=https://web.archive.org/web/20110124055506/http://www.psy.unipd.it/~tressold/cmssimple/uploads/includes/MetaFreeResp010.pdf |archive-date=2011-01-24 }}</ref> Hyman (2010) published a rebuttal to Storm ''et al''. According to Hyman, "Reliance on meta-analysis as the sole basis for justifying the claim that an anomaly exists and that the evidence for it is consistent and replicable is fallacious. It distorts what scientists mean by confirmatory evidence." Hyman wrote that the Ganzfeld studies were not independently replicated and failed to produce evidence for psi.<ref name=PsychologicalBulletin1>{{cite journal|last1=Hyman |first1=R |year=2010 |title=Meta-analysis that conceals more than it reveals: Comment on Storm et al |url=http://drsmorey.org/bibtex/upload/Hyman:2010.pdf |journal=Psychological Bulletin |volume=136 |issue= 4|pages=486–490 |doi=10.1037/a0019676 |pmid=20565165 |url-status=dead |archive-url=https://web.archive.org/web/20131103081111/http://drsmorey.org/bibtex/upload/Hyman%3A2010.pdf |archive-date=2013-11-03 }}</ref> Storm ''et al''. published a response to Hyman stating that the Ganzfeld experimental design has proved to be consistent and reliable, that parapsychology is a struggling discipline that has not received much attention, and that therefore further research on the subject is necessary.<ref name=PsychologicalBulletin2>{{cite journal | last1 = Storm | first1 = L. | last2 = Tressoldi | first2 = P. E. | last3 = Di Risio | first3 = L. | year = 2010 | title = A meta-analysis with nothing to hide: Reply to Hyman (2010)| journal = Psychological Bulletin | volume = 136 | issue = 4| pages = 491–494 | doi=10.1037/a0019840| pmid = 20565166 }}</ref> Rouder ''et al''. 2013 wrote that critical evaluation of Storm ''et al''.'s meta-analysis reveals no evidence for psi, no plausible mechanism and omitted replication failures.<ref>{{cite journal | last1 = Rouder | first1 = J. N. | last2 = Morey | first2 = R. D. | last3 = Province | first3 = J. M. | year = 2013 | title = A Bayes factor meta-analysis of recent extrasensory perception experiments: Comment on Storm, Tressoldi, and Di Risio (2010) | journal = Psychological Bulletin | volume = 139 | issue = 1| pages = 241–247 | doi=10.1037/a0029008| pmid = 23294092 }}</ref>