A quantitative examination of ostensibly extrasensory experiences occurring spontaneously and in laboratory conditions

  • Ben Leo Hugh Roberts

Student thesis: Doctoral ThesisDoctor of Philosophy


Parapsychological research, including the examination of the anomalous process termed ‘psi’, is highly controversial, with the existence of psi not accepted by mainstream science. The aim of this thesis was to study one aspect of psi, extrasensory perception (ESP), to examine whether evidence for ESP could be obtained or whether ostensibly extrasensory experiences can be attributed to purely psychological processes. Three studies are reported. The first obtained reports of spontaneous cases of ostensible ESP from 94 participants, using an online survey. Participants described their experience and responded to a series of questions regarding the aftermath of their experience and their reasoning for a paranormal interpretation. Results demonstrated several patterns that replicated earlier findings, including the predominance of female percipients, serious events, and close relationships between the percipient and target person. Negative emotions were common, including shock and confusion, particularly at the point of ostensible confirmation of the experience; the most common long-term response was an increase in paranormal belief, although some participants were relatively unaffected. Approximately two-thirds of participants had considered viable normal explanations for their experience, including coincidence and expectation of likely outcomes. Paranormal explanations were commonly attributed to the lack of a viable normal explanation, the striking coincidence between the experience and event, or the unusual nature of the experience. Many cases were weak evidentially; findings overall suggest that many ostensibly extrasensory experiences may have non-psi explanations. Two subsequent studies examined ESP in laboratory conditions, using the ganzfeld paradigm. Based on findings from spontaneous case research and previous laboratory studies, it was examined whether success was related to the emotional bond between pairs of participants, or to their sexes. The first study employed 30 pairs of participants, each taking part once as sender and once as receiver. Picture postcards were used as targets, and an emotional connectedness scale was used to assess pairing closeness. Direct hits and binary hits were above mean chance expectation (MCE); both were non-significant, although binary hitting was only marginally so. Results were suggestive of improved performance for closer pairings and mixed-sex pairings, but were non-significant. The second study was a partial replication, with 40 pairs of participants and using video clips as targets. EEG recordings were taken from the frontal midline (Fz) site of both participants. Approximately half of senders experienced stroboscopic stimulation at 6Hz throughout the trial in an attempt to drive theta rhythms associated with a hypnagogic state, mirroring the state expected in receivers due to ganzfeld stimulation. Direct hits were at MCE, while binary hits were non-significantly above MCE; binary hitting across the two studies was significant. There was no effect of pairing closeness or sexes on success, and hitting was not associated with any EEG features or with strobe usage.

Overall, laboratory findings appeared promising in terms of significant binary hitting but continued a trend of inconsistency within and between ganzfeld ESP studies. This inconsistency, together with the many weakly evidential spontaneous cases collected, point more strongly to a psychological interpretation of ostensibly extrasensory experiences, rather than the elusive psi.
Date of Award2013
Original languageEnglish
Awarding Institution
  • Coventry University
SponsorsBial Foundation
SupervisorIan Hume (Supervisor)


  • ESP
  • psi
  • parapsychology

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