Note 1: In the following, the term "déjà vu" will be used to stand for all forms of déjà experience, except where a more differentiated treatment is required.
Note 2: There is some overlap with both the history and explanations pages.
Note 3: An online questionnaire collected déjà experience data for 10 years, beginning in December, 2004. It was designed to compare the similarities and differences between incidences of déjà vévu and déjà visité. The results have been published by Funkhouser (2014, 2018). The Excel data file is available at https://figshare.com/articles/dataset/Survey_data_analysis_without_duplicates_as_of_Apr_17_2019_xls/11898474
What has been learned from surveys and questionnaires
Down through the years, several facts about déjà experience have been discovered with the help of questionnaires and surveys. The earliest one that I know of was conducted by H. F. Osborne at Princeton and elsewhere, and mentioned in his 1884 article that he published in the North American Review. Unfortunately he doesn't tell how many persons were interviewed (by questionnaire), or anything else about their ages, sex, education, etc. He does say, though, that about one-half had had some form of déjà vu experience.
In 1898, Bernhard-Leroy submitted his (medical) doctoral thesis on the illusion of false recognition (as it was also called). During his research, he distributed a questionnaire (1000 copies) and published it in a French magazine and in an American one. He received only 67 replies of which 49 were usable. He added to these 36 from the published literature which brought the total to 85. He did manage to ask about and record the aspects which Osborne had neglected but he found only one correlated factor: age. Most of the respondents said that they had had more frequent and more intense déjà vu experiences when they were younger, especially during their adolescence. This fact had already been noted, however, by Sander in 1873 and Kraepelin in 1886 - 87. On the other hand, there seemed to be no correlation with sex, race, class, state of health or energy level (fresh or fatigued).
Heymans, in 1904 and 1906, made a critical review of Bernhard-Leroy's results and extended the data by questioning the students in his classes, young people between 20 and 25 years of age, as he noted. In 88 cases, he found 14 (16%) who had often experienced déjà vu, and 41 (47%) who had experienced it occasionally. There seemed to be not much correlation with experiences of depersonalization, a relationship he had hoped to prove. There was more of a correlation with fatigue (see chapter 5). Probably his most interesting finding was that persons prone to déjà vu tended to have a more emotional, more labile nature than their peers.
With regard to incidence, Chapman and Mensh interviewed 220 patients, ambulatory and in bed, in the hospital and clinics of the Washington University (St. Louis). Their results, published in 1951, showed that 35% of the women and 31% of the men recalled having had déjà vu experiences. This agrees amazingly well with Lalande's 1893 estimate of 30% (see Ellis, 1911, p. 240). There seemed to be a slight positive correlation with intelligence (seen from education and occupation) and with travel (those who never traveled tended to have fewer déjà vu experiences). This may still be intelligence-related.) The clearest correlation was the one with adolescence, the highest incidence occurring between ages 15 and 25. The relationship with intelligence may be a spurious one: persons given to thinking and reflection might be more struck by the unusual nature of the experience so that they remember better their encounters with it. It would, though, explain the higher incidence among students as found in Heymans' study.
In 1967, a similar survey was carried out with 161 neurological and 301 psychiatric patients. Richardson and Winokur discovered that 40% and 44% (respectively) had experiences of déjà vu. They found a slightly higher incidence among women psychiatric patients (48%), but otherwise no significant sex differences. They also found that younger patients tended to experience déjà vu more often than older ones. The correlation with profession, education, and travel was substantiated in their data. They also had some African Americans patients in their sample population and found that the incidence of déjà vu among African Americans is significantly lower (only 19%). In a subsequent paper, they investigated the correlation of déjà vu with various neuro- and psychopathologies. Those results will be discussed on the Explanations page.
A few years later, in 1974, a survey by mail was made of 700 persons, picked at random from a telephone directory of Charlottesville, Virginia, by two students of the university there. Palmer and Dennis also sent out 300 to fellow students. With some effort, they managed to collect useful questionnaires from 89% of the students and 51% of the townspeople. Of those responding, 68% from the town and 88% of the student sample reported having had déjà vu experiences. Of the townspeople under 30, 84% gave positive responses. I suspect, though, that these figures can be brought into agreement with the results of the previous studies if we can assume that persons in the town who had had no experiences didn't bother to return the survey form. 68% of 51% comes to 35%. Similarly, 51% of 84% comes to 43%, reflecting the increased incidence among the young. The intelligence factor may be reflected in the much higher incidence among the students (88% of 89%, or 78% in the worst case). McKellar and Simpson, in a 1954 study of hypnagogic imagery, among 110 subjects chosen from the students at Aberdeen University in Scotland, found that 71% had experienced déjà vu.
The table below provides a synopsis of the information obtained in surveys, arranged chronologically, concerning the incidence of déjà vu in the general, healthy population. The grand average on the last line does not include the pre-1900 survey results.
Author(s) and year of publication | Population | No. of subjects | Incidence |
Wiedemeister (1871) | Normal, healthy adults | (unknown) | 33% to 50% |
Osborne (1884) | Normal, healthy adults | (unknown) | ~ 50% |
Lalande (1893) | Normal, healthy adults | 100 | 30% |
Bernhard-Leroy (1898) | Normal, healthy adults | 85 | 30% |
Harper (1969) | Normal, healthy adults | 91 | 62.2% |
Greeley (1975) | Normal, healthy adults | 1467 | 59% |
Palmer & Dennis (1974) | Normal, healthy adults | 357 | 68% |
McCready & Greeley (1976) | Normal, healthy adults | 1526 | 61% |
Neppe (1979) | female S. A. club members | 84 | 96% |
Kohr (1980) | A. R. E. members | 406 | 83% |
Neppe (1983) | Normal, healthy adults | 28 | 67.9% |
Greeley (1987) | Normal, healthy adults | 1473 | 67% |
Gallup & Newport (1991) | Normal, healthy adults | 1236 | 55% |
Fox (1992) | Normal, healthy adults | 3885 | 66.1% |
Levin (1993) | Normal, healthy adults | 1456 | 67.3% |
McClenon (1994) | American scientists (AAAS) | 339 | 59% |
Sno et al., (1994) | Normal, healthy adults | 59 | 71.2% |
Franze & Koschnitzki (1997) | Normal, healthy adults | 76 | 78.9% |
Adachi et al. (2001) | Normal, healthy adults | 386 | 76.68% |
Adachi et al. (2003) | Normal, healthy adults | 227 | 71.4% |
Total and mean percentage: | 13096 | 64.96% |
More recent surveys (Greeley, 1987; Gallup and Newport, 1991; Probst and Jansen, 1991; Levin, 1993) have also shown that déjà vu is a common occurrence in the general population with frequencies of incidence ranging from 54.6% to 89%, depending on how the question about déjà vu is phrased and which population is queried. It can thus no longer be considered paranormal (Greeley, 1975: Fox, 1992; Ross and Joshi, 1992) nor pathological (Hufford, 1992). As was found in the older surveys, these also found that it seems to be positively correlated with educational attainment (Fox, 1992).
McCready and Greeley (1976) surveyed 1526 persons within seven age ranges about their experiences of déjà vu. The average incidence for all 1526 came to 61%. The age dependence on incidence, as shown in the following table, is clearly seen from their results.
Age range |
No. of subjects |
Incidence |
Teens | 54 | 87% |
20s | 388 | 80% |
30s | 253 | 70% |
40s | 246 | 55% |
50s | 288 | 57% |
60s | 184 | 38% |
70s | 113 | 38% |
Average | 61% |
While they were at it, they looked into the incidence as related to religious convictions and found that déjà vu is claimed less often by Protestants and Catholics (58.5%) than among Jews and others (79.3%). Among 5 so-called mainline Protestant denominations, the Episcopalians were the most frequent experiencers of déjà vu.
A further, very interesting survey has been performed more recently by McClenon (1994) in which he interviewed students of various races and cultures in order to test what effects cultural source might have on so-called anomalous experiences. Based on questionnaire data from Chinese, Japanese and American universities as well as from members of the American Association for the Advancement of Science, he obtained the following frequencies for déjà vu incidence:
From 1984 to 1990, four students in the psychology department of the University of Hamburg under Prof. Paul Probst, conducted investigations about déjà vu in non-clinical populations. 42 students from four faculties at the university were recruited as subjects for the first study, the second was made with 130 police trainees, the third with 86 students, and the fourth with 97 medical students. Two concentrated just on how déjà vu was experienced while the other two were concerned with finding out what relationship there might be between depersonalization/derealization experiences and déjà vu. These have not been published in their entirety, but some of the results they obtained were summarized and made available in a (German) paper by Probst and Jansen (1991). A shorter version appeared in English in "The German Journal of Psychology" (Probst & Jansen, 1994).
Jansen (1991) tested 109 pupils (49 girls and 60 boys) with an average age of 16.1 from five classes in the 9th and 10th grades of a Niedersachsen primary school. They were subjected a battery of tests, including a 13 question déjà vu questionnaire that he had devised which included five questions (taken from Reed, 1979) having to do with Feeling of Knowing, Depersonalization, Tip of the Tongue, Time Gap, and Checking phenomena. A Cognitive Failure Questionnaire, an Everyday Attention Questionnaire, a Self-Attention Questionnaire, two Speed of Pattern Recognition tests, a Visual Memory test, and two Speed of Perception tests were also utilized.
A déjà vu incidence of 87.2% was obtained, but no significant influence of gender was found. A typical déjà vu experience lasted between 1 to 60 seconds for 70.5% of his subjects. 91.6% said it began suddenly, but only 51.6% said it ended suddenly. 36.9% said they found their déjà vu experiences to be pleasant while 48.8% said they were neither pleasant nor unpleasant. Only 4.8% found them to be very pleasant while 14.3% said they were unpleasant.
Like the previous table, the one below provides a synopsis of the information obtained from various surveys (including those of Prof. Probst's students), arranged chronologically, concerning the incidence of déjà vu in college-aged, healthy populations. One notes that the various incidences fall roughly into two groups: those around 70% and those around 85%. This may be due to how the déjà vu question was posed; this needs to be looked into.
Author(s) and year of publication | Population | No. of subjects | Incidence |
Heymans (1904, 1906) | University students | 88 | 62.5% |
McKellar & Simpson (1954) | University students | 110 | 71% |
McKellar (1957) | University students | 182 | 69.2% |
Buck & Geers (1967) | University students | 91 | 96% |
Buck (1970) | University students | 49 | 98% |
Myers & Grant (1972) | University students | 175 | 62.3% |
Palmer & Dennis (1974) | University students | 268 | 88% |
Rauwald (1984) | University students | 42 | 98% |
Berendt (1988) | Police trainees | 130 | 67.7% |
Krafft (1990) | Medicine students | 104 | 66% |
Jansen (1991) | High school students | 109 | 87.2% |
Schmutte (1990) | Psychology students | 86 | 82.6% |
McClenon (1994a) | Univ. of MD students | 214 | 89% |
McClenon (1994a) | Univ. of N.C. students | 532 | 86% |
McClenon (1994a) | ECSU (African-American students) | 391 | 80% |
McClenon (1994a) | Tsukuba Univ. students (Japan) | 132 | 88% |
McClenon (1994b) | Students from 3 Chinese universities | 314 | 64% |
Total and mean percentage: | 3017 | 78.9% |
For comparison, a study was made in Japan in the same year of 104 persons with temporal lobe epilepsy and it was found that 7, or 6.7%, had déjà vu and/or reminiscence (Sengoku, Toichi & Murai, 1997). This is a much lower rate than that found among healthy Japanese university students in the preceding study. The 1963 survey made by Cole and Zangwill produced similarly low values. These results along with those from surveys of other clinical populations are summarized in the table below.
Author(s) and date of publication | Population | No. of subjects | Incidence |
Lennox & Cobb (1933) | All epilepsy patients | 750 | 0.0013% |
Chapman & Mensh (1951) | Hospital patients | 220 | 33% |
Cole & Zangwill (1963) | Temporal lobe epilepsy patients | 110 | 12% |
Richardson & Winokur (1967) | Neurology patients | 161 | 40% |
Richardson & Winokur (1967) | Psychiatric patients | 301 | 44% |
Richardson & Winokur (1968) | Personality disorder patients | 11 | 81% |
Richardson & Winokur (1968) | Situational and adjustment reactions | 5 | 80% |
Brauer, Harrow & Tucker (1970) | Psychiatric patients | 84 | 92% |
Greyson (1977) | Schizophrenic patients | 20 | 65% |
Greyson (1977) | "Nonschizophrenic" patients | 65 | 51% |
Neppe (1983) | "Neuropsychiatric" patients | 48 | 73% |
Sengoku, Toichi & Murai (1997) | Temporal lobe epilepsy patients | 104 | 6.7% |
Sno et al. (1994) | Outpatients with major depression | 48 | 72.9% |
Sno et al. (1994) | Adolescents with schizophrenia | 42 | 76.2% |
Sno et al. (1994) | Temporal lobe epilepsy patients | 64 | 71.9% |
Pevin BN, Koveva OP (1999) | Organic brain disease | 273 | 5.4% |
Adachi et al. (2001) | Schizophrenia patients | 113 | 53.1% |
In 1994 Sno et al. extended Neppe's Screening and Quality questionnaires and included questions from those of Heymann and also Chapman and Mensh to create a standardized scale for investigating déjà vu (IDEA: Inventory for Déjà vu Experiences Assessment). This instrument was then used to compare the occurrence of déjà vu with that of depersonalization in individuals. In their investigation, 48 outpatients suffering from major depression, 42 adolescents with schizophrenic spectrum disorders, 64 outpatients with complex partial seizures (TLE) and 59 healthy subjects were tested. The incidence frequencies of déjà vu among these categories were 72.9%, 76.2%, 71.9% and 71.2%, respectively. They conclude that their results support a link between déjà vu and dissociative phenomena, confirm that it is more frequent among younger people and that there does not seem to be any gender dependence. (English and Dutch versions of the IDEA can be obtained by contacting Dr. Herman N. Sno).
In a survey made using the Internet (Snowden and Ito, 2001), questions from Sno's IDEA questionnaire and the Eysenck EPQ Personality Inventory scale were installed on a web-page and the data obtained from 352 "hits" was analyzed. 35 nations were represented among the respondents and a 97.4% affirmative rate provides further evidence that déjà vu occurs to individuals around the world. As to frequency, 49.6% reported ‘a few times per year’. Other frequencies were reported as: ‘a few times a month’ 27.9%, ‘less than one a year’ 12.5%, and ‘at least weekly’ 7.4%. 81.4% reported that they have had déjà vu incidents in situations that had occurred previously to them in a dream (cf. Funkhouser, 2000). 74.1% reported that while their déjà vu experience was happening, they felt they could predict what was going to happen in the next few minutes. 54.8% of 336 participants reported they had their first déjà vu experience between the age of 6 and 15. 9.8% said that their first experience occurred when they were between 16 and 25. About the same number (8.9%), though, said that their first experiences occurred when they were less than 5 years old. 26.2% said they were not sure. When asked to report at what age they had déjà vu incidents most frequently, 45.5% chose the age between 16 and 25, 12.3% for between 5 and 15, 6.9% for between 26 and 35, 0.8% for between 46 and 55, and 28.5% was not sure. 89.4% of the participants who experienced déjà vu reported their experiences lasted ‘less than a minute’ or a ‘couple of minutes’ and of that number (over half 52.1% claimed it lasted about a few seconds). Over 80% of the participants who reported déjà vu experiences denied having a negative mental condition at the time their déjà vu incidents, such as mental and physical fatigue, depression, nervousness, stress, anger, feeling of being frightened, drowsiness and/or physical illness. 61.9% of 331 reported, in fact, they were relaxed before the déjà vu experiences. 43.5% of 331 noted they were happy and cheerful before the incidents. Also, around 90% of the participants who reported déjà vu experiences noted that they have never had adverse physical conditions during their déjà vu experiences, such as headache, blackout, and epileptic seizures. Only one participant reported having a déjà vu experience during epileptic seizure.
Regarding the EPQ-R scores, a one-way ANOVA analysis demonstrated a highly significant relation between déjà vu incidence and extroversion (p = 0.004), but this probably says more about the type of person who responds to such surveys on the Internet than about some relationship between extroversion and déjà vu. The ANOVA result for the déjà vu incidence and the neurosis dimension, however, is non-significant (p = 0.475) and the psychotic dimension showed non-significance as well (p = 0.138). These results support the hypothesis that N and P scores are not significantly abnormal within a non-clinical population in association with déjà vu incidence. Those wishing more information about this investigation can obtain it by contacting Kei Ito (1999).
Mumoli et al. (2017) carried out a multi-center study with the intention of validating the Italian version of IDEA (I-IDEA) and at the same time of investigating the incidence and subjective qualities of the DV phenomenon in healthy Italian adult individuals. In this study, they reported normative data on the I-IDEA, collected on a sample of 542 Italian healthy subjects aged between 18–70 years (average age: 40) with formal education from 1–19 years. From September 2013 to March 2016, 542 healthy volunteers were recruited from 10 outpatient neurological clinics in Italy. All participants (i.e., family members of neurological patients enrolled, medical students, physicians) had no neurological or psychiatric illness and gave their informed consent to participate in the study. They self-administered the questionnaire and were able to complete I-IDEA test without any support. In total, 396 (73%) of the 542 healthy controls experienced the DV phenomenon. The frequency of DV was inversely related to age as well as to derealisation, jamais vu, precognitive dreams, depersonalization, paranormal activity, remembering dreams, travel frequency, and daydreams (all p < 0.012).
References
1. Adachi N, Adachi T, Kimura M, Akanuma N, Kato M: [Development of the Japanese Version of the Inventory of Deja vu Experiences Assessment (IDEA)] Seishin Igaku [Clinical Psychiatry] 43(11): 1223-1231, 2001.
2. Adachi N, Adachi T, Kimura M, Akanuma N, Takekawa Y, Kato M: Demographic and psychological features of déjà vu experiences in a nonclinical Japanese population. Journal of Nervous and Mental Disease 191(4): 242-7, 2003.
3. Adachi N, Akanuma N, Adachi T, Takekawa Y, Adachi Y, Ito M, and Ikeda H: Déjà vu experiences are rarely associated with pathological dissociation. The Journal of Nervous and Mental Disease 196(5): 417-9, 2008.
4. Berendt R: Déjà-Vu bei Gesunden: Quantative und qualitative Merkmale und der Zusammenhang mit spezifischen Denkweisen (nach Guilford) [Déjà vu in healthy people: Quantitative and qualitative characteristics and the relationship with specific ways of thinking (after Guilford)]. Master’s Theis, Universität Hamburg, 1988.
5. Bernhard-Leroy E: Etude sur l'illusion de fausse reconnaissance [Study of the illusion of false recognition]. Thesis, Faculté de Medecine de Paris. 1898.
6. Brauer R, Harrow M, Tucker GJ: Depersonalization phenomena in psychiatric patients. British Journal of Psychiatry 117: 509-15, 1970.
7. Buck LA: Varieties of consciousness: comparison of some cognitive characteristics. Perceptual and Motor Skills 30: 183-186. 1970.
8. Buck LA, Gears MB: Varieties of Consciousness: I. Intercorrelations. Journal of Clinical Psychology 23: 151-152, 1967.
9. Chapman AH, Mensh IN: Déjà vu experience and conscious fantasy in adults. Psychiatric Quarterly Supplement 25(2): 163-75, 1951-2.
10. Cole M, Zangwill OL: Déjà vu in temporal lobe epilepsy. Journal of Neurology and Neurological Psychiatry 26: 37-38, 1963.
11. Ellis H: Memory in Dreams. NYC: Houghton Mifflin & Co., Chapter IX, 1911.
12. Fox JW: The structure, stability, and social antecedents of reported paranormal experiences. Sociological Analysis 53: 417-431, 1992.
13. Franze M, Koschnitzki S: Déjà-Vu: Eine Studie zu Erforschung von Déjà-Vu-Erlebnissen unter persönlichkeitstheoretischen Aspekten [A study on research into déjà vu experiences from the perspective of personality theory]. Master’s Thesis. University of Koblenz-Landau, 1997.
14. Funkhouser A: The "dream" theory of déjà vu. Parapsychology Journal of South Africa 4:107-123, 1983.
15. Funkhouser A & Schredl M: Déjà vécu and déjà visité similarities and differences: Initial results from an online investigation. Journal of Consciousness Studies 21(11-12): 7 - 18, 2014.
16. Funkhouser A & Purser H: Déjà vécu and déjà visité similarities and differences: Further results from an online investigation. Explore 14(4):277-282, 2018.
17. Gallup GH Jr, Newport F: Belief in paranormal phenomena among adult Americans. The Skeptical Inquirer 15: 137-146, 1991.
18. Greeley AM: Deja vu, extrasensory perception, and clairvoyance. Chapter 2 in: The Sociology of the Paranormal: A Reconnaissance, Beverly Hills, CA: Sage Publications, 1975, pp. 9-33.
19. Greeley A: Mysticism goes mainstream. American Health Jan./Feb. 1987, pp. 47-49.
20. Greyson B: Telepathy in mental illness: deluge or delusion. Journal of Nervous and Mental Disease 165(3): 184-200, 1977.
21. Harper MA: Deja vu and depersonalization in normal subjects. Australian and New Zealand Journal of Psychiatry 3:67-74, 1969.
22. Heymans G: Eine enquete über depersonalisation und fausse reconnaissance [An inquiry concerning depersonalization and false recognition]. Zeitschrift für Psychologie und der Physiologie der Sinnesorgane. 36: 321-343, 1904.
23. Heymans G: Eine enquete über depersonalisation und fausse reconnaissance [An inquiry concerning depersonalization and false recognition]. Zeitschrift für Psychologie und der Physiologie der Sinnesorgane. 43: 1-17, 1904.
24. Hufford D: The Terror That Comes in the Night, Philadelphia: U of Pennsylvania Press, 1982.
25. Ito K: The déjà vu phenomenon in a non-clinical population. Master’s Thesis. The University of Buckingham.Arnzen, 1999.
26. Jansen J: Das Déjà vu-Erlebnis [The Déjà Vu Experience], Frankfurt: Peter Lang, 1991.
27. Kohr RL: A survey of psi experiences among members of a special population. Journal of the American Society for Psychical Research 74: 395-411, 1980.
28. Kraepelin E: Ueber Erinnerungsfälschungen [About memory falsifications]. Archiv für Psychiatrie 17: 830-843, 1886.
29. Krafft R: Déjà Vu und Depersonalisation: Eine empirische Untersuchung an einer nichtklinischen Stickprobe [Déjà Vu and Depersonalization: An Empirical Investigation in a Non-Clinical Population]. Master’s Thesis, University of Hamburg, 1990.
30. Lalande A: Des paramnesies [The paramnesias]. Revue Philosophique 36:485-497,1893.
31. Lennox WG: Cobb S, Aura in epilepsy: A statistical review of 1,359 cases. Archives of Neurology and Psychiatry 30: 374-387, 1933.
32. Levin JS: Age differences in mystical experience. The Gerontologist 33: 507-513, 1993.
33. McClenon J: Surveys of anomalous experience: A cross-cultural analysis. Journal of the American Society for Psychical Research 88(2): ll7-135, 1994.
34. McCready WC, Greeley AM: The Ultimate Values of the American Population. Beverly Hills: Sage, 1976.
35. McKellar P, Simpson L: Between wakefulness and sleep: Hypnagogic imagery. British Journal of Psychology General Section 45: 266-276, 1954.
36. McKellar P: Some Types of Individual Subjective Experience, Chapter IV in: Peter McKellar, Imagination and Thinking: A Psychological Analysis. London: Cohen & West, 1957.
37. Myers DH, Grant G: A study of depersonalization in students. British Journal of Psychiatry 121: 39-65, 1972.
38. Neppe VM: An Investigation of the Relationship between Subjective Paranormal Experiences and Temporal Lobe Symptomatology. Thesis. University of Witwatersrand, Johannesburg, 1979.
39. Neppe VM: The incidence of déjà vu. Parapsychological Journal of South Africa 4(2): 94-106, 1983.
40. Osborn, H F: Illusions of memory. North American Review 138: 476-486, 1884.
41. Palmer J: Dennis M, A community mail survey of psychic experiences. In: Research in Parapsychology, J. D., W. G. Roll and R. L. Morris (eds.), Scarecrow Press, Metuchen, N.J., 1975, pp. 130-3.
42. Piven BN, Koveva OP: [Non-convulsive paroxysmal disorders in exogenous-organic diseases of the brain]. Zhurnal Nevrologii i Psikhiatrii Imeni S.S. Korsakova, 1 Jan., 1999.
43. Probst P, Jansen J: Erlebnisse der Depersonalisation und des Déjà vu: Prävalenzen in nicht-klinischen Stichproben [Experiences of depersonalization and déjà vu: prevalences in non-clinical sample populations]. Zeitschrift für Klinische Psychologie, Psychopathologie und Psychotherapie 39: 357-368, 1991.
44. Probst P, Jansen J: Depersonalization and déjà vu: prevalence in non-clinical samples [Erlebnisse der Depersonalisation und des Déjà vu: Prävalenzen in nicht-klinischen Stichproben. Zeitschrift für Klinische Psychologie, Psychopathologie und Psychotherapie 39: 357-368, 1991]. Abstract No. 124. The German Journal of Psychology 18: 363-364, 1994.
45. Rauwald M: Depersonalisation und Déjà Vu: Eine empirische Untersuchung [Depersonalisation and Déjà Vu: an Empirical Investigation]. Master’s Thesis, University of Hamburg, 1984.
46. Reed G: Everyday Anomalies of Recall and Recognition. In: Functional Disorders of Memory, J.F. Kihlstrom and F. J. Evans (eds.), Hillsdale, NJ: Lawrence Erlbaum Associates, 1979.
47. Richardson TF, Winokur G: Déjà vu in psychiatric and neurosurgical patients. Archives of General Psychiatry 17(5): 622-5, 1967.
48. Richardson TF, Winokur G: Déjà vu -- as related to diagnostic categories in psychiatric and neurosurgical patients. Journal of Nervous and Mental Disease 146(2): 161-4, 1968.
49. Ross CA, Joshi S: Paranormal experiences in the general population. The Journal of Nervous and Mental Disease 180: 211-238, 1989.
50. Sander W: Ueber Erinnerungstäuschungen und Nervenkrankheiten [Concerning memory illusions and nervous diseases]. Archiv für Psychiatrie und Nervenkrankheiten 4: 244-253, 1874.
51. Schmutte K: Auftreten, Erleben und Bewältung von Deja-Vu Erlebnissen in einer nicht klinischen Population: Eine Validierungsstudie [Occurrence, experience and coping with deja vu experiences in a non-clinical population: a validation study]. Master’s Thesis, University of Hamburg, 1990.
52. Sengoku A, Toichi M, Murai T: Dreamy states and psychoses in temporal lobe epilepsy: mediating role of affect. The Journal of Neuropsychiatry & Clinical Neurosciences 51(1): 23-6, 1997.
53. Sno HN, Schalken HF, de Jonghe F, Koeter MW: The inventory for déjà vu experiences assessment. Development, utility, reliability, and validity. Journal of Nervous and Mental Disease 82(1): 27-33, 1994.
54. Snowdon W, Ito K: Déjà vu: Paranormal, pathological or everyday experience. VIIth European Congress of Psychology, Barbicon Centre, London, 2001.
55. Wiedemeister FW: Ueber doppeltes Bewusstsein bei Geisteskranken [Concerning doubled consciousness in the mentally ill]. Allgemeine Zeitschrift für Psychiatrie 27: 711-717, 1871.