Extrasensory perception: Does Psi Exist?

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Extrasensory perception Does Psi Exist?
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• Psi
• Anomalous processes of information or energy
  transfer, processes such a telepathy or other
  forms of extrasensory perception that are
  currently unexplained in terms of known physical
  or biological mechanisms. (Bem Honorton, 1994,
  p. 4)

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• The Ganzfeld procedure
• Based on the assumption that Psi is usually
  masked by internal somatic or external sensory
  noise.
• So, reduce internal and external noise through
  sensory deprivation.
• Sender concentrates on a visual stimulus
  selected randomly a large pool of stimuli
• Receiver provides continuous verbal report of
  ongoing imagery and thoughts (usually for 30
  minutes)

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• At completion of the Ganzfeld period, the
  receiver is presented with several stimuli
  (usually 4) and is asked to rate how similar each
  stimulus is to imagery and thoughts.
• Hit when highest rating is assigned to the
  target stimulus, that is, the stimulus the sender
  was concentrating on.
• With 4 alternatives, the hit rate expected by
  chance is .25.

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• Critique of previous meta-analysis
• Half of the studies were conducted by only 2
  laboratories Refuted
• Selective reporting Refuted
• Methodological flaws (sensory leakage, lack of
  adequate randomization) Some disagreement but
  mostly refuted
• Effect size is too small to be of practical or
  theoretical importance Refuted

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• Hyman and Honortons joint communique New rules
  for Ganzfeld research.
• Strict security precautions against sensory
  leakage
• Testing and documentation of randomization
  methods for selecting targets and sequencing the
  judging pool
• Advance specification of the status of the
  experiment (e.g., pilot study or confirmatory
  experiment)
• Full documentation in the published report of
  the experimental procedure

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• The Autoganzfeld procedure
• computer control of experimental protocol
• videotaped film clips as target stimuli

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• Results across studies 32 hit rate equivalent
  to a coin coming up heads (or tails) 59 of the
  time.
• Art students from the Julliard School in New
  York were uniquely successful 50 hit rate.
• Also highly successful were participants
  selected on the basis of their psi performance in
  previous sessions.
• Sessions using dynamic targets yielded
  significantly more hits than those using static
  targets.
• Friends did not perform better than did
  strangers.

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• Associations of individual differences with psi
  performance
• Better performance among those who
• Belief in psi
• Have personal psi experiences
• Are involved with meditation or other mental
  disciplines
• Have high scores on Feeling and Perceiving
  factors on MBTI
• Are high in extraversion

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• Assuming that psi exists, why does it exist?
• Noise reduction view Target information behaves
  like an external sensory stimulus (like sound or
  light) that is encoded, processed, and
  experienced in familiar information-processing
  ways.
• Psi-mediated information is conceptualized as a
  weak signal that is normally masked by internal
  or external sensory noise.
• Consistent with Role of receiver
  characteristics and role of dynamic versus static
  targets
• The Role of the Sender Is the sender needed?
  Telepathy versus clairevoyance.

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• The Physics of Psi
• Bells theorem Any model of reality that is
  compatible with quantum mechanisms must be
  nonlocal It must allow for the possibility that
  results of observations at two arbitrary distant
  locations can be correlated in ways that are
  incompatible with any physically permissible
  causal mechanism. (Bem and Honorton, 1994, p.16)

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• Hymans response
• Positive hit rate and statistical significance
  of psi in autoganzfeld experiments is due to
  dynamic targets. Because this is a new type of
  stimulus, further replication is required.
• Results from autoganzfeld experiments are
  inconsistent with those from ganzfeld
  experiments. Questions Bem and Honortons
  interpretation of performance by Julliard
  students and participants who believed in psi.
• Inadequate testing of randomization procedure
  leaves door open to alternative explanations.
  Targets favored by response biases (e.g., water)
  may have been selected more frequently.

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• Bems reply
• Hyman overstates inconsistencies and understates
  consistencies between ganzfeld and autoganzfeld
  studies
• If the heterogeneity of the original database
  and the methodological dissimilarities between
  its variables and those in the autoganzfeld
  preclude strong claims of consistency with
  regard to the role of dynamic pictures, then
  these same factors preclude claims of
  inconsistency with regard to the superior
  performance of friends. (p. 26)
• Additional analyses (e.g., how often was clip
  rated as target when it was the target as opposed
  to a decoy) demonstrate that psi cannot be
  attributed to the conjunction of unequal target
  distributions and content related response
  biases.