ESP in the twilight zone: The ganzfeld

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ESP in the twilight zoneThe ganzfeld
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ESP in dreams?

• Anecdotal reports of ESP in dreams
• Dream-ESP research

• Maimonides Dream Laboratory (1960s)
• Developed free-response ESP methods
• But dream research expensive and time-intensive

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Ganzfeld research

• Ganzfeld whole field
• Began in 1970s as alternative to dream research
• Cheaper
• Less time-intensive
• Used free-response methods
• Base on Noise Reduction Model

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Ganzfeld research
trees... buildings... clouds...
receiver
sender
attempts to psychically send target to receiver
reports imagery
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At end of session

• Receiver shown 4 pictures (3 decoys plus target)
• Must rate each picture in terms of matching
  imagery
• 25 chance of rating target picture highest

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Ganzfeld researchsummary of findings(source
Bem Honorton, 1994 Radin, 1997)1974 - 1997

• overall

• 50 studies (2549 trials) from 15 different
  laboratories
• hit-rate 33.2 (MCE 25)

• Psychophysical Research Laboratories (PRL)

• 1983 - 1989
• autoganzfeld studies 329 trials (200
  participants)
• 32 overall hit-rate
• dynamic targets better than static targets
  (37 vs. 27)
• 50 hit-rate for artistic students (n20)

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Ganzfeld researcha critical evaluation

• Could the findings be a fluke?
• can chance/coincidence explain results?
• Are the findings replicable?
• have they been independently replicated?
• Might it just be selective reporting?
• have all studies been published?
• Could findings be due to methodological flaws?
• are there other potential explanations instead of
  psi?
• Is weak psi effect of interest or importance?
• if it is a small effect... who cares?

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Meta-analysis of ganzfeld research

• combined probability of null hypothesis
• p lt 1x 10-16 (1 in 10,000,000,000,000,000)
• replication rates
• hit-rates comparable across 50 studies 15
  laboratories
• selective reporting
• file-drawer estimate around 500 unpublished
  null studies needed to make combined p gt .05
• role of methodological flaws
• no correlation between flaw ratings and study
  outcome
• effect size
• hit rate (i.e., 33.2) is an effect size
  descriptor
• medium effect size should be detectable
  without statistics

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Ganzfeld researchrecent developments

• Milton Wisemans (1999) meta-analysis
• 31 studies conducted 1986 to early 1997
• questions reliability of findings
• studies since 1997 show positive findings
• e.g. Dalton (1997) Symmons Morris (1997)
• ongoing debate over meta-analysis
• which studies to include?
• Storm Ertel (2001)
• further work planned
• improved methodology
• attempts to increase effect size

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Ganzfeld research at Liverpool Hope

• Digital autoganzfeld
• Fully computerized system
• Sender and Receiver rooms in separate buildings
• Recent project examining experimenter effects

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Useful references

• Bem, D. J. Honorton, C. (1994). Does psi exist?
  Replicable evidence for an anomalous process of
  information transfer. Psychological Bulletin,
  115, 4-18.
• Milton, J. Wiseman, R. (1999). Does psi exist?
  Lack of replicable evidence for an anomalous
  process of information transfer. Psychological
  Bulletin, 125, 387-391.
• Storm, L. Ertel, S. (2001). Does psi exist?
  Comments on Milton and Wisemans meta-analysis of
  ganzfeld research. Psychological Bulletin, 127,
  424-433.
• Milton, J. Wiseman, R. (2001). Does psi exist?
  Reply to Storm and Ertel (2001). Psychological
  Bulletin, 127, 434-438.