The Disembodied Self: An Empirical Study Of Dissociation And The Out-Of-Body Experience - bibliography included

Harvey J. Irwin

ABSTRACT: Recent developments in the study of dissociation prompted a re-examination of the nature of the out-of-body experience (OBE). A questionnaire survey of Australian university students addressed the relation between the OBE and nonpathological dissociation (psychological absorption), pathological mental dissociation, and pathological somatoform dissociation. Both the occurrence of the OBE and the frequency of OBEs were found to be predicted by somatoform dissociation. The findings are discussed with reference to the extent to which the OBE should be considered a pathological phenomenon. A dissociational theory of the OBE is formulated; this depicts the experience as a dissociation between the sense of self and the processing of somatic events.

The out-of-body experience (OBE) is one in which "the center of consciousness appears to the experient to occupy temporarily a position which is spatially remote from his/her body" (Irwin, 1985, p. 5). In the book Flight of Mind, written some 15 years ago (Irwin, 1985), I advanced a theoretical account of the OBE that stressed the involvement of various features of the cognitive--personality construct known as psychological absorption. Absorption is a state of strong engrossment in one's mentation and has been defined formally as "a 'total' attention, involving a full commitment of available perceptual, motoric, imaginative and ideational resources to a unified representation of the attentional object" (Tellegen & Atkinson, 1974, p.274). Most other behavioral scientists at the time were inclined to designate the OBE as an instance of depersonalization (e.g., Whitlock, 1978). Since the late 1980s a resurgence of research interest in the topic of dissociation (D. Spiegel & Cardena, 1991) has served to repositi on both psychological absorption and depersonalization in the broader context of dissociative processes, reinstating their original conceptualization by Pierre Janet in the 19th century (Janet, 1889; van der Hart & Friedman, 1989). It is therefore timely to reconsider the OBE in relation to the concept of dissociation.

Mental processes such as thoughts, memories, feelings, and the sense of identity ordinarily are integrated. D. Spiegel and Cardena (1991) described dissociation as a structured separation of these processes; that is, one cognitive process may appear to proceed independently of another such process when ordinarily one might expect the two processes to be intrinsically linked. By way of illustration, in the relatively common dissociative state known as "highway hypnosis" drivers may become so engrossed in their daydreams or other mentation during a long journey that the mental processes associated with driving evidently are dissociated from consciousness; nonetheless, the "vehicle steering" mental processes evidently continue to be executed, given that the road is successfully navigated. For many people in the general population this type of dissociative experience is reportedly a familiar part of everyday life (Ross, Joshi, & Currie, 1990), although in some cases dissociative processes may become more patholo gical, possibly to the extent that they constitute one of the psychological dysfunctions known formally as the dissociative disorders (D. Spiegel, 1991/1993).

In phenomenological terms the OBE entails an experient's (henceforth, OBE-er's) impression that the self has separated from the body, and on this ground the OBE is designated a parapsychological experience, that is, one in which it seems to the experient that a paranormal phenomenon is involved (Irwin, 1999a). It is uncertain, however, that a paranormal process actually does underlie the OBE. Indeed, despite creative attempts to demonstrate experimentally the paranormality of the experience (e.g., Osis, 1975) it is doubtful that a conclusive study to this end can be designed (Blackmore, 1994). For this reason many researchers have opted to investigate the OBE as a psychological event that coincidentally may or may not be conducive to extrasensory awareness (Alvarado, 1992). It is in this context that there arises the notion of the OBE as a dissociative phenomenon.

In normal circumstances a person's sensory processing of kinesthetic and somaesthetic stimuli may serve to maintain the assumption that consciousness, or the thinking and perceiving self, is "in" the physical body; that is, somatic processing ordinarily is integrated with a sense of self. Such is not the case during an OBE. In this sense the OBE has been deemed a dissociative event simply by definition (e.g., D. Spiegel & Cardena, 1991; Steinberg, 1991/1993). On the other hand, the OBE cannot adequately be explained by declaring it to be an instance of dissociation. Rather, a dissociational theory of the OBE would have to specify how the functional separation of particular cognitive processes might account for all the diverse aspects of the experience's phenomenology. The present study was in part intended to provide some empirical justification for the development of a dissociational theory of the OBE.

In seeking to relate the OBE to dissociation it is important at the outset to appreciate that dissociation is not a unidimensional domain. An adequate acknowledgment of this fact has emerged only in the last few years. Researchers previously had assumed that dissociative tendencies form an intrinsic continuum, ranging from very low levels in some members of the general population to very high levels among dissociative-disordered patients (e.g., Ross, 1989). Although it was evident that some dissociative phenomena (e.g., psychological absorption) were much more common than others (e.g., depersonalization), the concept of a "dissociative continuum" (H. Spiegel, 1963) had long been a premise of the empirical investigation of the dissociative domain. Recent research nevertheless suggests that the assumption of a unitary dissociative continuum is erroneous, or at least an oversimplification.

Waller and his colleagues (Waller, Putnam, & Carlson, 1996; Waller & Ross, 1997) have identified two distinct types of dissociation, only one of which is dimensional. Using the statistical approach of taxometric analysis, Waller et al. (1996) found that pathological dissociative experiences, such as depersonalization and dissociative amnesia, are in fact taxonic; that is, people can be dichotomized into two distinct groups according to whether they have had such experiences. This taxonic form of dissociation does not constitute a continuum. Although scores on Waller et al.'s index of pathological dissociation (the Dissociative Experiences Scale--Taxon) are numerically continuous, the underlying factor is inherently classlike rather than traitlike. In addition, pathological dissociation evidently has no genetic component (Waller & Ross, 1997) and seems at least in part to be a product of severe childhood trauma (Irwin, 1999b; Kroll, Fiszdon, & Crosby, 1996).

Waller et al. (1996) also identified a second, nonpathological type of dissociation that evidently does constitute a continuum. According to Frank Putnam (personal communication, April 19, 1996), this dimensional type of dissociation is best indexed by experiences of psychological absorption. The capacity to achieve this state of high engrossment in experience shows the statistical characteristics of a personality trait or dimension (Tellegen & Atkinson, 1974) and is believed to have a normal distribution in the general population. Psychological absorption is closely related to fantasy proneness (Wilson & Barber, 1983) and indeed, the two constructs might not be truly discriminable (Lynn & Rhue, 1988). Thus, nonpathological dissociation might usefully be thought of as a capacity for imaginative involvement. The nonpathological dissociative trait is also reported to have a substantial genetic component (Finkel & McGue, 1997; Tellegen et al., 1988), although it certainly is not immune from environmental influe nce (Vanderlinden, van Dyck, Vandereycken, & Vertommen, 1993).

Although there is a need for independent replication of Wailer et al.'s (1996) findings, in the present context it may be noted that there is some evidence that the OBE is correlated with these two types of dissociative tendencies. In a series of studies in the 1980s I established that OBE-ers presented with a relatively high capacity for psychological absorption (Irwin, 1980, 1985)--and, conversely, people with high absorption capacity were relatively susceptible to an experimental OBE-induction technique (Irwin, 1981). The link between OBEs and absorption has been replicated by researchers in other countries (Glicksohn, 1990; Myers, Austrin, Grisso, & Nickeson, 1983). In addition, fantasy proneness is reported to be higher among OBE-ers than among nonexperients or "non-OBE-ers"] (Hunt, Gervais, Shearing-Johns, & Travis, 1992; Myers et al., 1983; Wilson & Barber, 1983). It would seem, therefore, that a capacity for nonpathological dissociation is a factor in the occurrence of the OBE. This interpretation ac cords with several aspects of the phenomenology of the experience (Irwin, 1985).

The relation between OBEs and pathological dissociative tendencies has been given scant empirical scrutiny, despite the fact that most psychiatrists and psychologists classify the OBE as an instance of depersonalization, that is, of pathological dissociation (Steinberg, 1995). Thus, generally speaking, researchers have not sought to establish that OBE-ers as a group are marked by pathological dissociative tendencies (apart from the "symptom" of the OBE itself). Alvarado and Zingrone (1997), however, found Waller et al.'s (1996) DES-T index of pathological dissociation to discriminate between OBE-ers and non-OBE-ers better than did a set of mainly absorption items. This is a most important finding for the construction of theories of the OBE, and one of the primary objectives of the present study was to try and replicate the result obtained by Alvarado and Zingrone.

It would seem, however, that there is even more to the dissociation domain than the distinction between pathological and nonpathological dissociation documented by Waller et al. (1996). Contemporary North American researchers construe dissociation in terms of mental functions. Thus, D. Spiegel and Cardena (1991, p. 367) defined dissociation as "a structured separation of mental processes." Janet's (1889, 1907/1965) original formulation of the concept of dissociation, on the other hand, was applicable to both psyche and soma. According to Janet, dissociation could result in an alteration of bodily, or somatic, functions as well as mental processes (Nijenhuis & van der Hart, 1999).

Some European researchers have now revived the notion of dissociative processes related to somatic states and functions. Nijenhuis and his coworkers (Nijenhuis, 1999; Nijenhuis, Spinhoven, van Dyck, van der Hart, & Vanderlinden, 1996, 1998b; Nijenhuis & van der Hart, 1999) have operationalized this facet of dissociative processes in the concept of somatoform dissociation, defined as "dissociation which is manifested in a loss of the normal integration of somatoform components of experience, bodily reactions and functions" (Nijenhuis, Spinhoven, van Dyck, van der Hart, & Vanderlinden, 1998a, p. 713). While acknowledging that mental and physiological processes are intrinsically interrelated, Nijenhuis maintains that there is a clear phenomenological distinction between the manifestations of mental (or psychological) dissociation and those of somatoform dissociation and that researchers' neglect of the latter needs to be redressed. In many instances of somatoform dissociation there is a "deficit symptom," or lo ss of somatic function, that has no evident organic basis; for example, a person may report numbness (anesthesia) in a part of the body or the loss of a sensory function (e.g., so-called hysterical blindness). Somatoform dissociation can also comprise a "positive symptom" or addition to somatic functions, such as psychosomatic pain or tics.

Nijenhuis and his colleagues (Nijenhuis, 1999; Nijenhuis et al., 1996, 1998b) have demonstrated the construct of somatoform dissociation to be psychometrically coherent. In addition, these researchers have gathered evidence to suggest that somatoform dissociation is pathological in nature; for example, somatoform dissociation correlates more strongly with pathological (mental) dissociation than with nonpathological dissociation (absorption) and has been found to be related to a history of severe childhood trauma (Nijenhuis, 1999; Nijenhuis et al, 1996, 1998a). Nonetheless, the correlation between somatoform dissociation and (other) pathological dissociation is about .7 (Nijenhuis et al., 1996); that is, barely half ([7.sub.2] = .49) of the common variance is accounted for. Thus, although somatoform dissociation may be pathological, it seems to be both qualitatively (phenomenologically) and quantitatively distinct from pathological mental dissociation.

An investigation of the relation between the OBE and dissociative tendencies therefore should take due account of somatoform dissociation in addition to both pathological mental dissociation (henceforth referred to simply as pathological dissociation) and nonpathological dissociation (psychological absorption). To date no research has sought to examine the OBE in relation to somatoform dissociation. Nonetheless, there is a clear rationale for undertaking such a project. As indicated earlier, the argument for the potential relevance of dissociative processes to the OBE is that at a phenomenological level the OBE appears to entail a dissociation between sensory processing of somatic (somaesthetic and kinesthetic) events and the sense of self or identity. This interpretation of the OBE seems fundamentally to implicate somatoform dissociative processes. Note there is no necessary suggestion here that somatoform dissociation would be the sole type of dissociative mechanism involved in the OBE, but there is ample justification to include somatoform dissociation in an investigation of the nature of the OBE.

In summary, the objective of the study was to investigate the relation between OBE occurrence and three facets of dissociation, namely, pathological, nonpathological, and somatoform dissociative tendencies.

METHOD

Participants

The study was undertaken as a postal questionnaire survey of adults enrolled in an off-campus introductory psychology course taught through the University of New England, Australia. Students in this course generally are of mature age; most are in paid employment, some are homemakers. Survey forms were completed by 113 students. The sample comprised 28 men and 85 women, ranging in age from 19 to 64 years (M = 35.6, Mdn = 33, SD = 10.34).

Materials

The survey inventory contained three questionnaires. One was a brief form surveying demographic variables and OBEs; the other two were related to dissociative tendencies. Each of these will be described in turn.

The first questionnaire asked respondents for their gender and age; these items were included not only to ascertain basic sample characteristics but also because there are some reports suggesting that proneness to dissociation may vary with gender and age (Irwin, 1994; Ross, Ryan, Anderson, Ross, & Hardy, 1989; Torem, Hermanowski, & Curdue, 1992). Participants also were asked if they had had OBEs and, if so, how many. The item surveying the occurrence of OBEs was one originally devised by Palmer (1979):

I have had an experience in which I felt that "I" was located "outside of" or "away from" my physical body; that is, the feeling that my consciousness, mind, or center of awareness was at a different place than my physical body. (If in doubt, please answer "False" (p. 231).

Proneness to both pathological and nonpathological dissociation was measured by the DES, developed by Bernstein and Putnam (Bernstein & Putnam, 1986; Carlson & Putnam, 1993). The DES is a 28-item self-report measure indexing the frequency of various experiences of dissociative phenomena in the respondent's daily life. For example, one item concerns looking into a mirror and not recognizing oneself (an instance of pathological dissociation); another item concerns lack of awareness of nearby events while watching television or a movie (an instance of psychological absorption). With the version of the DES used in this study, for each item the participant is instructed to circle a number on a 21-point scale (that ranges from 0 to 100 in 5% increments) so as to indicate the percentage of time he or she has the nominated dissociative experience. The DES has been shown to have good reliability (Cronbach's [alpha] = .95, test-retest reliability = .79-.96; Carlson & Putnam, 1993; Frischholz et al., 1990), and its con current and discriminative validity has been extensively documented (Carlson & Putnam, 1993; Frischholz et al., 1991; van IJzendoorn & Schuengel, 1996).

For the purposes of this project the DES was used to generate two scores for each participant. One score, based on eight items of the scale, indexed the pathological form of dissociation (the DES-T; Waller et al., 1996). The second score, derived from 12 DES items in the case of nonclinical samples (Ross, Ellason, & Anderson, 1995), is a measure of psychological absorption, the key nonpathological dimension of the dissociative domain. Scores on both of these facets of dissociation are computed as the mean of responses to the component items and thus can range from 0 to 100. On each scale high scores signify strong (pathological or nonpathological) dissociative tendencies.

Proneness to somatoform dissociation was measured by the Somatoform Dissociation Questionnaire (SDQ-20; Nijenhuis, 1999; Nijenhuis et al., 1996, 1998b). The SDQ-20 comprises 20 items relating to physical symptoms and bodily experiences indicative of somatoform dissociation (e.g., "My body, or a part of it, is insensitive to pain"). On each item respondents are asked to indicate on a 5-point scale (1 = not at all to 5 = extremely) the extent to which the statement is applicable. A total score is computed as the sum of ratings over the 20 items and thus can range from 20 to 100, with high scores taken to indicate substantial proneness to somatoform dissociation. The SDQ-20 has been shown to have good reliability (Gronbach's [alpha] = .95-.96) as well as impressive factorial purity, and its convergent and discriminative validity has been adequately documented (Nijenhuis, 1999; Nijenhuis et al., 1996, 1998b).

Procedure

A "plain language" statement was attached to the front of the inventory mailed to potential participants. This statement described the topic of the study and stressed that participation was voluntary and anonymous. Participants were not required to put their names on any of the survey forms; the plain-language statement explained that the return of the completed form would in itself be taken to signify students' informed consent to participate in the project. An appeal was made to participants to respond to all questionnaire items as spontaneously and openly as possible. Participants returned their completed forms in a stamped envelope supplied by me.

RESULTS

Preliminary comment is appropriate on the scoring of the DES-T as an index of pathological dissociation. One of the items of the DES relating to depersonalization, Item 7, has some affinity with the OBE:

Some people sometimes have the experience of feeling as though they are standing next to themselves or watching themselves do something and they actually see themselves as if they were looking at another person. Circle a number to show what percentage of the time this happens to you (p. 231).

There is some cause for debate as to whether this item should be included in the DES-T index when testing if pathological dissociative tendencies are related to the OBE. On the one hand, inclusion of the item might be seen as using an item about OBEs to predict the occurrence of OBEs. On the other hand, exclusion of the item might be seen to compromise the breadth and the psychometric integrity of the DES-T as a measure of pathological dissociation. In the following statistical analyses Item 7 of the DES was retained as a component of the DES-T score. Two points nevertheless should be noted in this regard. First, and most pragmatically, when this item was excluded from the DES-T score no substantial difference in the pattern of statistical results was found. Second, it may be stressed that the experience addressed by Item 7 of the DES is not identical to the OBE. Thus, the item also accommodates the autoscopic hallucination in which a person sees his or her own "double" but does not have an impression of bei ng outside the body (Dening & Berrios, 1994; Lukianowicz, 1958). Conversely, some OBE-ers do not report seeing their physical body during the experience and would respond in the negative to Item 7. Indeed, for the present sample 59% of OBE-ers gave a rating of zero on Item 7, and 16% of non-OBE-ers gave a rating greater than zero, which is contrary to the view that this item addresses nothing other than the OBE. Although a positive relation certainly obtains between the two variables (for a simplified 2 x 2 contingency table [[chi].sup.2][1, N = 113] = 8.78, Cramer's V = .28, p [less than] .005), there can be no reasonable claim of a simple equivalence between OBEs and the experiences tapped by Item 7 of the DES.

Of the 113 people in the sample 44 acknowledged having had an OBE. This level of incidence (38.9%) is broadly comparable to data for similar samples I have surveyed throughout the 1980s and in the 1990s (Irwin, 1985, 1988, 1996). The estimated number of OBEs reported by experients ranged from 1 to 100. Descriptive statistics (mean and standard deviation) on the independent variables are given in Table 1.

To assess the relation between dissociative tendencies and the occurrence of the OBE, a standard logistic regression analysis was undertaken with DES Absorption, DES-T, SDQ-20, gender, and age as predictors of OBE-er status. A logistic regression determines which variables serve differentially to predict group membership (in this case, OBE-ers and non-OBE-ers) and is especially useful when one or more of the individual predictor variables is not normally distributed (Tabachnick & Fidell, 1996), as is the case here; in a standard logistic regression analysis all predictor variables are entered simultaneously. The analysis, conducted with SPSS software (SPSS, Inc., 1995), evidenced a significant multivariate result (-2 log likelihood = 129.3, goodness of fit = 108.2, [[chi].sub.2][5, N = 113] = 21.75, p = .0006), that is, the set of independent variables predicted group membership to a significantly better degree than a model in which the difference between groups was a simple constant. No problems with multicolli nearity of independent variables were found (Tabachnick & Fidell, 1996, p. 618). A summary of the analysis is given in Table 2; this shows the regression coefficients and their standard errors, the results of Wald's test with the associated degrees of freedom and level of significance, and the multivariate correlations. According to the associated classification matrix, the logistic regression equation correctly identified 34% (15 of 44) of OBE-ers in the sample and 91% (63 of 69) of non-OBE-ers. The only predictor variable independently to discriminate OBE-ers from non-OBE-ers was the SDQ-20 (R = .162, p = .015).

A further analysis was undertaken to assess the extent to which dissociative tendencies predicted the number of OBEs that respondents estimated they had had. To this end, a standard multiple regression analysis was used to assess the predictability of OBE frequency from the independent variables of DES Absorption, DES-T, SDQ-20, age, and gender; all nonexperients of course were scored as having zero OBEs. Because the frequency distributions of OBE frequency and dissociation scores were substantially skewed, an inverse transformation was first applied to these variables. In a standard multiple regression all independent variables enter into the regression equation simultaneously; this is the recommended method when there are insufficient theoretical grounds for controlling the order of entry of variables (Tabachnick & Fidell, 1996). Again, analysis was conducted using SPSS software (SPSS, Inc., 1995).

Table 3 presents the unstandardized regression coefficients and intercept; the standardized regression coefficients; the semipartial correlations; and R, [R.sub.2], and adjusted [R.sub.2]. By way of explanation, a semipartial correlation represents the contribution of a given independent variable to [R.sub.2] when the contribution of other independent variables is removed from both the dependent variable and the particular independent variable; thus, a semipartial correlation coefficient is a useful indicator of the unique contribution of the independent variable to the total variance of the dependent variable (Tabachnick & Fidell, 1996). In addition, given that the various types of dissociative tendencies are likely to intercorrelate, it is important to inspect so-called tolerance statistics (Tabachnick & Fidell, 1996) and ensure that intercorrelations among predictor variables do not compromise the analysis. All tolerance statistics in the regression were well above zero, ranging from .51 to .97; multicoll inearity of transformed predictor variables therefore was of no practical concern (Darlington, 1990).

The multiple correlation R for the regression was significantly different from zero, R= .48, F(5, 107) = 6.38, p [less than].0001; that is, OBE frequency was significantly related to the set of independent variables. Altogether, 23% (or 19% adjusted) of the variability in the number of OBEs was predicted by scores on the measures of dissociation, gender, and age. Only one of the independent variables contributed significantly to the prediction of OBE frequency, namely, the SDQ-20 ([sr.sup.2] = .107, p = .0002).

DISCUSSION

The findings of this study support the view that the OBE is related to dissociative phenomena. The logistic regression analysis of the predictors of OBE occurrence identified somatoform dissociation as the only independently significant contributor to the regression equation. The pivotal role of somatoform dissociation was confirmed in the regression analysis of OBE frequency; here the sole variable independently predictive of OBE frequency was somatoform dissociation.

To the extent that somatoform dissociation is a fundamentally pathological process (Nijenhuis et al., 1998a), the study is broadly supportive of Alvarado and Zingrone's (1997) report that the OBE is related to pathological dissociation. In addition, the latter finding is advanced by the present study in its indications that the particular type of pathological dissociative tendency most pertinent to OBE occurrence is somatoform in nature. This observation is reminiscent of Wickramasekera's (1993) impression that there is a link between parapsychological experiences more generally and susceptibility to stress-related somatic symptoms. In essence, it seems that people who have OBEs, especially those who have many OBEs, tend to be characterized by a persistent proneness to dissociate in the somatic domain.

Caution must nevertheless be exercised against overpathologizing the OBE on the basis of these findings. It would certainly be overstating the case to claim that the OBE represents a deficit somatoform symptom. It must be remembered that the SDQ-20, the index of somatoform dissociation used in this study, was intentionally designed to comprise items about specifically pathological somatoform symptoms (Nijenhuis et al., 1996). Not all somatoform dissociation, however, may be pathological; like mental dissociation, somatoform dissociation might range in form from pathological to nonpathological. The present findings may well implicate pathological dissociation and specifically pathological somatoform dissociation in both the occurrence and frequency of the OBE, but there may also exist some less pathological somatoform dissociative tendencies that underlie cases in which a person only has one or two OBEs or has "milder" forms of OBE. (for more on the latter, see Jacobs & Bovasso, 1996). Further research into t his possibility is impeded by the current unavailability of a measure of nonpathological somatoform dissociative tendencies. In any event, at present it is appropriate to place more emphasis on the somatoform quality than the pathological quality of the dissociative tendencies associated with the OBE.

It must also be emphasized that the effect sizes found in the study are by no means large: For OBE occurrence, only 34% of OBE-ers (but 91% of non-OBE-ers) were correctly classified, and for OBE frequency the multivariate R for the regression equation was .48. The moderate effect sizes might be explained in part by the fact that some nonexperients with high dissociative tendencies might well have an OBE at some time in the future; that is, dissociation might be more strongly related to an individual's capacity to have OBEs than the present research design is able to demonstrate. A more likely explanation, however, is that there are factors in addition to dissociative tendencies that have a bearing on whether a person will have (or will report having) an OBE. A few other personality characteristics and cognitive skills have been identified (for a review see Irwin, 1999a), but there remains a need for substantial further empirical investigation in this regard.

As I have argued elsewhere (Irwin, 1985) a theoretical account of the OBE must comprise more than a mere specification of factors that explain why the person feels as if the self is exteriorized during the experience. There are many other facets of the phenomenology of the OBE, and an adequate theory must address these subjective events, too. With this in mind I now offer an outline of a theory that (somewhat speculatively) reformulates my earlier account (Irwin, 1985) in terms of the dissociative domain. The following model is essentially a dissociational theory of the OBE.

The origins of the OBE are hypothesized to lie in a confluence of dissociative factors. Circumstances associated with extreme (either high or low) levels of cortical arousal evoke a state of strong absorption, particularly in the case of a person with a requisite level of absorption capacity and need for absorbing experiences. Alternatively, high absorption may be induced deliberately by the experient. If this state of absorbed mentation is paralleled by a dissociation from somatic (somaesthetic and kinesthetic) stimuli, an OBE may occur. People who are prone to this type of somatoform dissociation may generally be said to have tendencies toward depersonalization. There may nevertheless be various pathological and nonpathological factors underlying this propensity (Jacobs & Bovasso, 1996), and the OBE therefore should not automatically be construed as a pathological symptom.

In instances where the development of the state of somatic dissociation is gradual, the imminent loss of all somatic contact may be signaled by certain innate biological warning signals, the so-called OBE-onset sensations.

The continued orientation of attention away from both exteroceptive and somatic stimuli effectively suspends support for the socially conditioned assumption that the perceiving self is "in" the physical body, fostering the impression that consciousness no longer is tied spatially to the body. This abstract, nonverbal idea of a disembodied consciousness is coded by the cognitive processing system into a passive, generalized somaesthetic image of a static floating self. Consciousness of that image corresponds to the so-called asensory OBE. By means of the dissociative process of synesthesia the somaesthetic image also may be transformed into a visual image, given a basic level of visuospatial skills in the experient.

Strong absorption in this image is a basis for the OBE's perceptual realism. The somaesthetic image also may be transformed into a more dynamic, kinesthetic form, and the experient will have the impression of being able to move in the imaginal out-of-body environment. The somatic imagery entailed in this transformation is held to underlie the phenomenon of the parasomatic form. A drawing of attention back to the physical body's state also may be expressed synesthetically by way of the image of the astral cord.

The perceived content of the out-of-body environment is governed by short-term needs. A life-threatening situation, for example, may prompt imagery about a paradisial environment; the nature of the latter is held to be a product of social conditioning, although the precise sources of these paradisial stereotypes have yet to be identified fully (see Irwin, 1987). Because dissociation is psi conducive it is possible that the out-of-body imagery could incorporate extrasensory information and thereby feature a degree of veridicality not expected of mere fantasy; empirical documentation of extrasensory elements in spontaneous OBEs, however, is not yet convincing. Eventual dissipation of somatic dissociation or a diversion of attention to somatic or exteroceptive processes brings the individual's OBE to an end.

The above outline of a dissociational theory of the OBE is offered not as a definitive description but as a constructive stimulus to further research effort. One issue for research in this context is the extent to which the three types of dissociative tendencies help to illuminate individual phenomenological features of the OBE.

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            DESCRIPTIVE STATISTICS ON RESEARCH MEASURES FOR THE
             COMPLETE SAMPLE (N = 113), OUT-OF-BODY EXPERIENTS
         (OBE-ERS, N= 44), AND NONEXPERIENTS (NON-OBE-ERS, N = 69)
                    Full sample       OBE-ers       Non-OBE-ers
Variable                 M       SD      M     SD        M       SD
Nonpathological        15.28    14.31  19.51  16.42    12.58    12.17
dissociation
(DES Absorption)
Pathological disso-     4.94     8.91   8.28  12.56     2.80     4.39
ciation (DES-T)
Somatoform disso-      23.36     5.80  25.91   8.13    21.74     2.59
ciation (SDQ-20)
Age (years)            35.64    10.34  33.68   9.74    36.89    10.59
No. OBEs                3.38    13.54   8.64  20.76     0.0      0.0
Note. DES = Dissociative Experiences Scale; DES-T = Dissociative
Experiences Scale - Taxon; SDQ-2O = Somatoform Dissociation Questionaire.
        STANDARD LOGISTIC REGRESSION OF NONPATHOLOGICAL DISSOCIATION
            (DES ABSORPTION), PATHOLOGICAL DISSOCIATION (DES-T),
            SOMATOFORM DISSOCIATION (SDQ-20), GENDER, AND AGE ON
             OBE OCCURRENCE (OBE-ERS VS NON-OBE-ERS) (N = 113)
Variable          B    SE  Wald  df  p    R
DES Absorption  -.021 .027  .569 1  .451 .000
DES-T            .088 .063 1.912 1  .167 .000
SDQ-20           .163 .067 5.940 1  .015 .162
Gender (female) -.648 .483 1.799 1  .018 .000
Age             -.015 .022  .486 1  .486 .000
Note. N = 113. Intercept = -3.605. OBE = out-of-body experience; DES =
Dissociative Experiences Scale; DES-T = Dissociative  Experiences

Scale-Taxon; SDQ-20 = Somatoform Dissociation Questionnaire.
        STANDARD MULTIPLE REGRESSION OF NONPATHOLOGICAL DISSOCIATION
      (DES ABSORPTION), PATHOLOGICAL DISSOCIATION (DES-T), SOMATOFORM
          DISSOCIATION (SDQ-20), GENDER, AND AGE ON OBE FREQUENCY
                                   [sr.sup.2]
Variable          B       ?    p    (unique)
DES Absorption   -.059  -.020 .851
DES-T             .127   .131 .272
SDQ-20          20.129   395  .000    .107
Gender (female)   .123   .149 .086
Age               .0007  .019 .830
Note. N = 113. Intercept = -1.516; [R.sup.2] = .23;
Adjusted [R.sup.2] = .19; R = .48; p [less than] .0001.
DES = Dissociative Experiences Scale; DES-T = Dissociative
Experiences Scale - Taxon; SDQ-20 = Somatoform Dissociation
Questionnaire; OBE = out-of-body experience.

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