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Foreword to Psychology of Déjà Vu (Professor Lewis Hurst)

It is a privilege indeed to have been asked to write a foreword to what I regard as one of the major works of scientific and imaginative genius of our time. Dr. Vernon Neppe has mobilized, for the understanding of that fascinating phenomenon on the frontiers of human experience, déjà vu, the resources of literature, logic, biology, psychology, psychiatry, and neurology in an incomparable synthesis. He has pursued his quest relentlessly by an original many-sided research investigation of impeccable design, issuing in this, our definitive work in the field. From one perspective, this research may be seen as the crystallization of Dr. Neppe`s work in placing Parapsychology on the map scientifically in South Africa, building on the pioneer work of Professors Arthur Bleksley, Marius Valkhoff, and Michael Whiteman. From another angle, the present book is characterized by rigorous logical thought issuing in formal definitions, operational definitions, classifications of both a normal and clinical type in relation to déjà experience, as well as the most highly sophisticated differential diagnosis of such entities as temporal lobe dysfunction, temporal lobe epilepsy and schizophrenia, that have been found to be associated with a proportion of Neppe's déjà vu experients. The statistical analysis of results, although non-parametric owing to sample size, has nevertheless been conducted in a detailed and expert manner. But it is not only from the quantitative aspect that this study excels, but on the qualitative side also we find a delightful range of personal portrayals of déjà vu experiences, intriguing and stimulating to the imagination, from such literary sources as Nathaniel Hawthorne, Joseph Heller, Charles Dickens, Marcel Proust and Lafcadio Hearn, as well as from Neppe's own experimental subjects. The contributions to an understanding of déjà vu and related phenomena from the full range of disciplines conceivably involved, (including psychiatry, psychology, neuro-anatomy, neuro-physiology, neuro-chemistry, general medicine, neurology and pharmacology) are subtly conceptualized by Neppe, and thereafter exhaustively explored with the utmost scientific rigor and acumen before his setting out of his original study - both on Normal subjects (subjective paranormal non-experients and experients) and on Neuropsychiatric categories (chiefly temporal lobe epilepsy and schizophrenia). The clinical elucidation of this case material is enlivened by apt and vivid illustrative vignettes.

In transforming his doctoral thesis, intended primarily for specialized medical readers, to this book, for perusal also by scholars of other disciplines and the general public comprising intelligent laymen, attracted by a theme of such universal appeal, Dr. Neppe has gone to great pains to promote intelligibility through a Glossary of medical and technical terms, and readability by printing matters of subordinate allows a unitary detail (e.g., the foreign terms for variants of déjà vu) in smaller type. Moreover the statistical analysis has been compressed, in the knowledge that the original doctoral work can be consulted for the fuller treatment of the data.

Neppe's main theoretical conclusion of this work merits quotation in full - 'déjà vu is the epiphenomenon underlying numerous different phenomenologies. This would imply that Temporal Lobe Epileptic Déjà Vu is associated with a specific pattern of cerebral firing, that Schizophrenic Déjà Vu is symptomatic of the underlying reality distortion, that Subjective Paranormal Experience Déjà Vu should be classified as a kind of subjective paranormal experience with heteropsychic origins and that Associative Déjà Vu is due to a redintegrative restricted paramnesia mechanism, possibly learnt "as an unconscious reassurance-type ego-defense."

Further research avenues envisaged are:

  1. The application of Neppe's structured questionnaire as a projective test in schizophrenia.
  2. The induction of déjà vu (or restricted paramnesias) in temporal lobe epileptics, subjective paranormal experients and schizophrenics.
  3. A prospective study on subjects who frequently experience déjà vu.
  4. Extension of the investigation to larger populations particularly of normal subjects.
  5. Transcultural studies of the phenomenon.
  6. Psychopharmacological trials on déjà vu in temporal lobe epileptics and schizophrenics.
  7. Study of the implications of the occurrence of déjà vu in affective illness, implying less specificity for schizophrenia.
  8. Prospective examination of frequency of déjà vu in relation to his setting out of dream recall, in view of the preliminary impression from the present study of an association.
  9. Further study is necessary to ascertain whether there is a correlation of déjà vu with age, and what its prevalence is in children. This book describes the two youngest cases in the literature and raises the question as to whether 5 is the lowest age limit for déjà vu, as providing the cognitive and affective developmental prerequisite.

A final synthetic formulation of Neppe's achievement with its profound theoretical and practical potential enshrined in this book, is that his classification of déjà vu experience based on the medical model, allows a unitary conceptualization of diagnosis, follow-up and prognosis as well as incidence, pathogenesis, etiology, clinical features and for the fuller response to treatment.

Dr. Neppe concludes in terms of the imagery of Plato's Allegory of the Cave, with true philosophical and scientific humility asking the questions: How many shadows have been perceived in this research? Has this study just looked at an epiphenomenon?

20 June 1982
Professor Lewis A. Hurst

BA B.Sc. MB ChB PhD (Cape Town)
MD (Pretoria) FRCPsych (London)
Professor Emeritus (Psychiatry)
Hon. Research Professorial Fellow (Genetics)
University of the Witwatersrand, Johannesburg



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