Varieties of Self Disorder: A Bio-Pheno-Social Model of Schizophrenia

Abstract

The self-disorder model offers a unifying way of conceptualizing schizophrenia’s highly diverse symptoms (positive, negative, disorganized), of capturing their distinctive bizarreness, and of conceiving their longitudinal development. These symptoms are viewed as differing manifestations of an underlying disorder of ipseity or core-self: hyper-reflexivity/diminished-self-presence with accompanying disturbances of “grip” or “hold” on reality. Recent revision to this phenomenological theory, in particular distinguishing primary-vs-secondary factors, offers a bio-pheno-social model that is consistent with recent empirical findings and offers several advantages: (1) It helps account for the temporal variations of the symptoms or syndrome, including longitudinal progression, but also the shorter-term, situationally reactive, and sometimes defensive or quasi-intentional variability of symptom-expression that can occur in schizophrenia (consistent with understanding some aspects of ipseity-disturbance as dynamic and mutable, involving shifting attitudes or experiential orientations). (2) It accommodates the overlapping of some key schizophrenic symptoms with certain nonschizophrenic conditions involving dissociation (depersonalization, derealization), including depersonalization disorder and panic disorder, thereby acknowledging both shared and distinguishing symptoms. (3) It integrates recent neurocognitive and neurobiological as well as psychosocial (eg, influence of trauma and culture) findings into a coherent but multi-factorial neuropsychological account. An adequate model of schizophrenia will postulate shared disturbances of core-self experiences that nevertheless can follow several distinct pathways and occur in various forms. Such a model is preferable to uni-dimensional alternatives—whether of schizophrenia or ipseity-disturbance—given its ability to account for distinctive yet varying experiential and neurocognitive abnormalities found in research on schizophrenia, and to integrate these with recent psychosocial and neurobiological findings.

Introduction

Schizophrenia, perhaps the “sacred symbol” of psychiatry, is also one of psychiatry’s most problematic disorders—given the variety, changeability, and sheer strangeness of its manifestations, and the uncertainty of its boundaries (supplementary material note I). One influential attempt to define schizophrenia is the self-disorder or ipseity-disturbance model currently prominent in phenomenological psychopathology.¹ New developments in formulating this phenomenological self-disorder concept make this now particularly attractive: a bio-pheno-social model capable of capturing not only the unity-cum-heterogeneity and distinctive bizarreness of schizophrenia’s developing symptoms, but also its symptomatic overlapping with dissociative conditions, its variability with circumstances, and its reactive, sometimes even quasi-intentional quality.² The model can also integrate recent empirical findings regarding psychosocial as well as neurobiological causes and correlates.

Self-Disorder Model of Schizophrenia

The basic-self-disorder or ipseity-disturbance model postulates an abnormality of basic or minimal self-awareness, of the normal, first-person quality of experience—ie, of ipseity: the core sense of existing as the subject of one’s own experience and agent of one’s own actions. William James called this the “central nucleus of the Self.” Ipseity—which is grounded in the lived body and inner time-consciousness—is experienced not as an entity in one’s field of awareness, but as the unseen point of origin for experience, thought, and action; as a medium of awareness, source of activity, or general directedness toward the world. It grounds the first-person givenness or for-me-ness of subjective life.

The self or ipseity disturbance in schizophrenia is hypothesized to have three main aspects. The first, “hyper-reflexivity,” refers to an exaggerated self-consciousness, a tendency (fundamentally nonvolitional) for focal attention to be directed toward processes and phenomena that would normally be “inhabited” or experienced (tacitly) as part of oneself. The second, “diminished-self-presence,” refers to a decline in the (passively or automatically) experienced sense of existing as a subject of awareness or agent of action. The third, “disturbed grip or hold,” concerns accompanying alterations in the organization or feel of the field of awareness—alterations affecting the tacit-focal structure (salience-pattern), affordance-quality, or reality-status of the world (Figure 1, panel A).^1,2

Fig. 1.

Heuristic diagram of proposed bio-pheno-social model of basic self-disorder in schizophrenia. (A) Three phenomenological aspects of basic self-disorder (ipseity-disturbance) in schizophrenia. Each aspect likely occurs as both a primary and a secondary factor. Arrows can represent causal or quasi-causal processes, but also phenomenological “implication” (complementarity of aspects). (B) Proposed bio-pheno-social model of schizophrenia, incorporating primary and secondary factors, pheno- and neuro- levels.

The intertwining or complementarity of these aspects or processes is apparent: eg, whereas “hyper-reflexivity” emphasizes that something normally tacit becomes focal or explicit, “diminished self-presence” emphasizes the other side of this same process—the fact that what once was tacit can no longer be inhabited as a medium of taken-for-granted selfhood” (supplementary material note II). This basic-self alteration involves alterations at the level of the lived-body.³ It has profound implications for both interpersonal and intersubjective dimensions of existence—given that hyper-reflexivity and altered self-presence distract from and disrupt normal social interaction, while also undermining the individual’s sense of being grounded in a shared, common-sense universe (an intersubjective world) organized in accord with standard human desires and projects. This type of self-disturbance in schizophrenia is distinct from disturbances of narrative selfhood, which are thought to rely on “metacognitive” processes⁴ (though disruptions of basic self can also interfere with construction of a coherent narrative self⁵) (supplementary material note III).

The ipseity-disturbance model offers a novel formulation. It draws, however, on earlier attempts to capture the core disorder in schizophrenia, especially from phenomenological psychopathology.^1,6 These include Karl Jaspers’ emphasis on schizophrenia’s “bizarre” or difficult-to-comprehend essence, which he associated especially with disturbance of the “cogito”; Josef Berze’s positing of a fundamental alteration or “primary insufficiency” of self-awareness; Klaus Conrad’s emphasis on a “constant reflexive attention” or “stepping-back” from experience; Eugene Minkowski’s notion of “loss of vital contact” as the “trouble générateur”; and Wolfgang Blankenburg’s notion of loss of “natural self-evidence” (the latter 2 especially relevant to disturbed “grip”).

Recent Research

The ipseity-disturbance model has received crucial support from a series of studies using the “EASE: Examination of Anomalous Self Experience,” a semi-structured interview that operationalizes the ipseity-disorder model. Such research has clearly demonstrated that self-anomalies consistent with this model are indeed far more common in schizophrenia-spectrum individuals than in severe depression or bipolar illness, or in heterogeneous samples of psychiatric patients.⁷ In addition, clinical/theoretical analyses suggest that, despite some superficial similarities, the severe affective symptoms do not involve the disruption of core-self experience that seems to account for the often “bizarre” quality of schizophrenia’s key symptoms.^8,9 The recently published “EAWE: Examination of Anomalous World Experience” will allow further empirical investigation of world- or object-oriented disturbances/anomalies (concerning space and objects, time and events, other persons, language, and overall “atmosphere”) associated with the ipseity-disturbance model.¹⁰

Recent work has gone beyond these general associations in several ways: (1) through theoretical analysis of self-disorder’s relevance for pathogenetic explanation^2,11; (2) by specifying schizophrenic self-disorder in comparison with several nonschizophrenic conditions whose self-experience can resemble schizophrenia—whether superficially (mania and psychotic depression)⁸ or more profoundly (depersonalization disorder, panic disorder, introspectionism;^12–14 the hyper-reflexivity and alienation of literary and artistic modernism/postmodernism affords particularly revealing analogues¹⁵); (3) by integrating neurobiological and psychosocial theories and findings.^16,17 Crucial to this revised model is a distinction between primary and secondary aspects of the illness and its symptoms.

At the risk of some oversimplification, one might distinguish between more fundamental, enduring, trait-like features that are largely automatic or passively experienced (termed “operative”—as opposed to “reflective”—by the philosopher Merleau-Ponty), versus more consequential or compensatory features that develop largely in response.^11,16,17 It should be noted that both hyper-reflexivity and diminished-self-presence can occur in both a primary and a secondary fashion. Hyper-reflexivity can involve an exaggerated and self-alienating self-scrutiny that occurs in defensive reaction to, or as an attempt to cope with: (1) more primary or “operative” experiential disruptions (but now contributing a largely reflective hyper-reflexivity), or (2) traumatic environmental circumstances. It may, however, also occur more passively and as a component of a more primary affliction, as, eg, when there is a kind of automatic popping-out of kinesthetic or other sensations that would have normally been subsumed as part of the standard, tacit experience of the lived-body (operative hyper-reflexivity). Similarly, diminished self-presence, a kind of depersonalization, can occur as a self-protective or defensive response to trauma (as occurs in PTSD), but may also derive from some more foundational weakness or affliction of self-experience.

All this is congruent with schizophrenia’s pathogenetic complexity, which is known to involve both early and enduring, perhaps inborn, neurocognitive vulnerabilities^16–18 as well as later developments involving responses (both long- and short-term) to these endogenous factors and challenging life circumstances (thus implying 2 pathways—usually interacting—to psychosis¹⁹). (Early trauma can, of course, itself foster a state of vulnerability to later traumatic experiences.) It is noteworthy, in this light, that schizophrenic self-disorder typically comprises prominent dissociative symptoms, particularly depersonalization and derealization, and that (as recently documented)^12,20 schizophrenic and dissociative-disorder symptoms appear to overlap considerably (also, a subset of EASE items are practically identical to symptoms in the Cambridge Depersonalization Scale) (supplementary material note IV).²¹

These associations are especially important in light of recent evidence of the pathogenetic role in schizophrenia of environmental/social stressors, including childhood trauma and abuse, social defeat, and cultural dislocation/alienation.^22,23 It seems likely that some key aspects of the ipseity-disorder found in schizophrenia would involve dissociative reactions to such stressors—though these reactions would also interact with (and be altered by) the earlier or more inborn vulnerabilities (also interpretable as disorder of core self, albeit of a somewhat different kind, as explained below) (supplementary material note V). One recent path-analysis study (of nonclinical subjects) indicated a probable interaction of self-disorder with trauma in creating psychosis proneness.²⁴

Several lines of research support this view.

Depersonalization Disorder and Introspectionism

Two quasi-empirical studies examined the presence of EASE-like self-anomalies in conditions that lie outside the schizophrenia spectrum yet seem to involve either hyper-reflexivity or diminished-self-presence.^12,13 They explored the extent to which conditions incorporating key elements of the postulated self-disorder, but not themselves schizophrenic, might manifest EASE anomalies, thereby suggesting the capacity of the postulated factors to account for cardinal features of schizophrenia involving self-disorder. In these studies, the EASE categories were applied not to interview responses, as in most past research, but to published accounts, first, of depersonalization disorder (which, virtually by definition, is dominated by experiences of diminished self-presence) and, second, of exaggerated introspection (the early 20th-century psychological technique, which clearly involves a deliberate or reflective form of hyper-reflexivity). These conditions would seem to involve largely secondary forms of ipseity anomaly: While the secondary or reflective hyper-reflexivity of introspectionism is volitionally initiated, the loss of self-presence in depersonalization is generally assumed to involve a goal-directed—albeit not usually consciously initiated—process of psychological defence (rather than a more primary, foundational, or “operative” type of diminished self-presence) (supplementary material note VI).

These quasi-empirical studies showed that the majority of EASE items were indeed found in both the depersonalization disorder (72% of items) and introspection (77%) accounts, thereby suggesting considerable experiential overlap with schizophrenia-spectrum (“affinities”).^12,13,25 Prominent in depersonalization and introspection as well as in schizophrenia were EASE items indicating feelings of passivity and alienation (eg, “perceptualization of inner speech or thought”; “constant self-monitoring”) and alienation or fading of self and world (“diminished presence”). However, items more suggestive of severe dislocation, erosion, or dissolution of first-person perspective (such that self and other can seem fused or confused) tended more often to be absent from either depersonalization or introspection. Whereas the first, dissociation-like items (affinities) may reflect more compensatory factors in certain cases, the latter (discrepancies) may primarily reflect something more grounded in earlier, more affliction-like anomalies.

We note that both this methodology and these findings contrast with prior applications of the EASE—which have not examined individual EASE items in a differential fashion, but have treated these items only as diverse indications of a “core Gestalt” of ipseity-disturbance, whose extent is presumably indexed by an overall EASE score.²⁶ We believe it is necessary to consider the structure or component aspects of ipseity-disturbance in order effectively to explore its temporal variability, pathogenesis, and neural correlates (supplementary material note VII).

Panic Disorder

The just-mentioned findings from the quasi-empirical depersonalization and introspection studies were corroborated in a recent empirical study comparing 47 hospitalized panic disorder patients with 47 healthy controls—in this case using, not previously published self-descriptions, but standard EASE interviewing (conducted by experienced psychiatrists with EASE-workshop training).^14,21 Like the depersonalization and introspectionist subjects described just above, the panic disorder patients also reported many EASE items suggesting common forms of derealization and depersonalization—perhaps involving more “secondary” and defensive psychological processes in the development of these disorders. However, they too tended to lack the EASE items suggesting truly profound distortion of subjective life, consciousness, or “basic self” (eg, confusing one’s own subjectivity with that of another person) that might be related to a more “primary” factor in schizophrenia. The overall EASE scores of the panic disorder sample were much higher than those found in previous (and comparable) EASE-interview studies of bipolar psychosis or miscellaneous nonschizophrenia-spectrum psychiatric samples (though lower than in schizophrenia-spectrum patients). All this supports a revised self-disorder model which recognizes that schizophrenic self-disorder may well incorporate defensive or other “secondary” phenomena, some of which may involve forms of depersonalization and derealization that also occur outside the schizophrenia-spectrum. It suggests that the EASE items (at least many of them) are somewhat less specific to schizophrenia-spectrum conditions than is sometimes claimed.

Neuropsychological Dimensions: Salience, Source-Monitoring, Default-Mode

This refined self-disorder model is consistent with current theory and knowledge about neuro-cognition and brain function in schizophrenia, and offers a framework for integrating a plethora of findings. Some prominent neurocognitive theories concern salience anomalies, disturbances of source-monitoring, and abnormalities of default mode network (DMN).

Salience disturbance (involving limbic-system over-activity) manifests as a failure of attention to be automatically directed toward novel or significant stimuli, but to focus on random, habitual, or normally insignificant stimuli, which now stand forth in disconcerting (and sometimes delusion-inspiring) ways. This clearly implies disturbed grip, for it disrupts the normal pragmatic orientation/organization of one’s cognitive/perceptual field. Among the stimuli that stand forth are phenomena of bodily or cognitive experience that would normally be experienced tacitly, and thereby inhabited as the very medium of selfhood; and this implies a kind of alienating hyper-reflexivity now directed toward such phenomena as kinesthetic sensations and inner speech.²⁷ The relevance of disrupted source-monitoring (presumably involving disturbances of corollary discharge and associated prediction errors) for core self-experience is particularly obvious, given that it disturbs the ability to recognize when an action or perceptual change is or is not initiated or produced by the self.^28–30 A third set of findings concerns abnormal activation, in schizophrenia, of the DMN, the coordinated set of brain-activity-patterns that is normally associated with inner-directed rumination (a form of hyper-reflexivity) and diminished practical engagement (implying a form of diminished-self-presence) with external tasks.^31–33

It would be mistaken to treat any of these 3 factors in a static or reductionistic fashion. Each seems likely to represent something more like an orienting tendency, a shifting attitude or experiential stance that varies over time (namely hyperawareness, detachment from active engagement in one’s own actions, ruminative introspection).^2,11 Such tendencies are also found in various disorders outside schizophrenia spectrum, and with and without psychotic symptoms. It is noteworthy, in fact, that the neural correlates at issue closely resemble dissociative states, which are generally recognized as serving defensive functions, as in PTSD (2 recent publications link disrupted source-monitoring to both schizophrenia and dissociative disorders^29,34). These propensities may reflect underlying neurological tendencies (defensive and volitional patterns exploit inherent capacities); but they may also have a goal-directed or quasi-intentional quality consistent with the documented quasi-intentional (also termed “quasi-agentive”) aspects of schizophrenia.^15,35

To appreciate the role of secondary factors, especially those having an intentional or quasi-intentional aspect, requires acknowledging the key role not only of self-anomalies but also of the person or of personhood. In addition to experiencing foundational or primary alterations of ipseity, the patient may also adopt, in more active fashion, certain attitudes toward or orientations within his or her illness—stances involving, eg, active scrutiny of perceptual anomalies, willful withdrawal toward inner fantasy, or exaggerated alienation from or contrarianism toward common-sense ideas or customs. Such person-level attitudes toward, or reflection on, one’s illness and its anomalies may, in turn, have implications for the nature and course of the illness itself.^15,36–38

It seems plausible, then, that several key processes (hyperawareness, detachment from one’s own actions, ruminative introspection) might represent consequential and compensatory responses to a more foundational vulnerability and to environmental stressors. Though “secondary” in the sense of occurring later in time (perhaps only slightly later, or perhaps primarily in adolescence—when capacities for reflection and disengagement mature), these processes might nevertheless be equally necessary for development of a characteristically schizophrenic form of illness, with its typical depersonalization and derealization as well as its distinctive eccentricity.^17,39

Neuropsychological Dimensions: Primary and Secondary

There are various candidates for a more “primary” pathogenetic factor.¹⁸ A particularly strong one involves disturbed “perceptual integration”—found in schizophrenia patients and also (to a milder degree) in children who are at high risk for schizophrenia-spectrum disorders.^16,40–47 Perceptual dys-integration has been repeatedly found in schizophrenia patients and, though not unique, seems relatively specific to it. Also, unlike other neurocognitive abnormalities mentioned above, it seems fairly constant and likely to be an early trait-factor, given that it has been found in children at high risk for schizophrenia-spectrum.^16,41,43,48 Its potential theoretical relevance can be readily explained.

Perceptual integration refers to the synthesizing of information from different sense modalities, perhaps especially between interoceptive and exteroceptive processes, such as kinesthesia/proprioception and visual perception (mediated by medial/lateral prefrontal cortex, temporoparietal junction and/or insular cortex). Successful perceptual integration would, presumably, provide a crucial foundation for establishing normal core-self experience (ipseity, involving body ownership and agency) early in life, contributing to unified object-perception but also to the (complementary) senses of being grounded in one’s own body and of constituting a particular viewpoint on the world.⁴¹ (Normal subjects subjected to “multisensory conflict” were found to have a schizophrenia-like experience involving profound self-disturbance: feeling “as if a virtual body seen in front of them was their own body and mislocalizing themselves toward the virtual body, to a position outside their bodily borders.”)⁴⁹ Indeed, the neural circuitry of perceptual integration might well constitute the neural foundation of basic self-experience and the capacity to differentiate self from other (supplementary material note VIII).^16,50 One intriguing interpretation of ipseity-disorder would postulate disturbed temporality or basic time-experience.^51,52 Such a view, emphasizing decline in the felt temporal flow that normally imbues the “now-moments” of conscious life (perhaps reflecting disturbed linkage between temporal and spatial dimensions in resting-state activity),³³ is consistent with classic phenomenology’s (Husserl’s, for example) linkage of ipseity with inner time-consciousness (supplementary material note IX).

Perceptual dys-integration does seem, in any case, to occur before other features, such as disturbed reality monitoring (a type of source monitoring).⁴³ Such disturbance of multisensory integration is also fairly specific to schizophrenia—more so than salience dysregulation, aberrant source-monitoring, or DMN abnormalities. It is however found also in autism-spectrum disorder, which, interestingly enough, does have some symptomatic and neurocognitive affinities with schizophrenia—eg, connectivity abnormalities—and some shared genetic and perinatal risk-factors.⁵³

It is plausible that such dys-integration might be an early trait-factor underlying foundational, primary, or “operative” forms of disruptive hyper-reflexivity, diminished self-presence, and disturbed cognitive/perceptual “grip” on the world (together with associated “basic symptoms”).^32,54–56 Other factors, more associated with shifting attitudes or orientations to experience, more reactive or defensive (and thus more state-dependent, within psychotic or symptomatic episodes—albeit also grounded in neurocognitive capacities and tendencies) might come into prominence somewhat later in the causal sequence (Figure 1, panel B).¹⁷ There is, in fact, significant evidence of a correlation between the intensity of all 3 of these latter neurocognitive factors and intensity of psychotic symptoms (supplementary material note X).

Both primary and secondary factors may be necessary, but neither sufficient, for creating schizophrenic self-disturbance. Primary factors may be more decisive in so-called “poor premorbid” patients or cases with early or “insidious” onset, who are often dominated by negative symptoms and “nonparanoid” features. Secondary factors may be more crucial for cases with more acute onset and better premorbid functioning, and with more prominent positive and perhaps especially dissociation-like symptoms, as well as for acute exacerbations under conditions of stress.^19,57 This temporally extended approach to self-disturbance is consistent with other recent neuroscientific²⁹ and neurobiological⁵⁸ discussions of the time-dependent evolution of symptoms. It is also compatible with dimensional models of psychosis, providing a phenomenological perspective on the impact of genetic risk and adverse events on foundational processes of basic self-experience.⁵⁹

Two Meta-Issues: Holism, Mind-Body Problem

In conclusion, we will mention 2 meta-issues that arise in offering our integrative account: One concerns the relation between component processes and the possibility of a more foundational or encompassing core disturbance. The other concerns the causal relation between the biological and phenomenological planes: Are these parallel manifestations of the same problem or condition, or does one cause the other?

Both questions pertain to theoretical issues that are difficult or even impossible to settle, such as overall attitudes toward holistic explanation or the enigmatic mind/body problem (generally viewed as utterly insoluble). There is, in any case, no basis for assuming (as sometimes occurs) that component processes must be causally primary, or that physical reductionism is necessarily valid (namely, that causality runs always and only from brain-to-mind rather than in the opposite direction). Indeed there is urgent need for research that explores the variable nature of both neurocognitive and neurobiological trends. Such research would manipulate overall mental orientation or stance (eg, subject adopting a withdrawn/introspective vs practical focus; scrutiny vs a spontaneous orientation) and study the effects of these changes in both schizophrenic and normal subjects—in order to determine the extent to which various symptomatic or sub-symptomatic alterations, including alterations of self and world such as perceptual fragmentation, salience dysregulation, and disturbed sense-of-agency (or their milder equivalents), together with their neural correlates, might alter in accord with such changes (supplementary material note XI).^2,42,60

Two studies have already shown, in fact, that adoption, by normal subjects, of an altered overall experiential orientation—namely, of an intensely introspective/detached stance—can bring about “psychedelic” forms of perceptual experience akin to what occurs in schizophrenia, including diminished agency and body ownership, permeable ego boundaries, and ineffability.^13,60,61 It would be surprising if neuro-level abnormalities were not also produced, at least to some degree, by shifting attitudes or orientations on the subject’s part. Such abnormalities are often ascribed to component processes such as abnormal corollary discharge or salience dysregulation. They may, however, be dependent on (though not entirely the product of) varying defensive or even intentional or quasi-intentional factors—akin to depersonalization defenses, introspectionism, and perhaps some forms of meditative practice,⁶² all of which can be understood as involving an altered overall orientation or attitudinal stance (with obvious relevance to the above-mentioned dimension of personhood). It would be interesting to study, for instance, the extent to which either the experience or neural correlates of auditory-verbal hallucinations might be mimicked (albeit to a lesser degree) by a person who withdraws and focuses attention on his own inner thinking. To what extent would, eg, perception of the concave mask or perceptual fragmentation⁴² be increased under conditions of introversive withdrawal, either in normal or in schizophrenic subjects? Such research could help clarify the complex syntheses of primary and secondary factors in the pathogenesis of schizophrenia. Its potential relevance for devising treatments to alleviate abnormal tendencies could be considerable.

Summary

The ipseity-disturbance hypothesis (postulating hyper-reflexivity/diminished-self-presence with accompanying disturbances-of-grip) offers a unifying way of conceptualizing schizophrenia’s diverse symptoms, and of conceiving their longitudinal development.^1,9 Recent formulation of these self-disturbances, in particular distinguishing primary-vs-secondary factors, offers a bio-pheno-social model consistent with recent empirical findings and offering certain advantages: (1) it helps account for the temporal variations of the symptoms or syndrome—not only longitudinal progression from vulnerability through prodrome into psychosis (already interpreted as a gradual exacerbation of hyper-reflexivity and diminished self-presence), but also the shorter-term and possibly defensive or quasi-volitional variability of symptom-expression that is prominent in schizophrenia (consistent with understanding ipseity-disturbance as dynamic and mutable, involving shifting attitudes or experiential orientations, including person-level attitudes and self-awareness); (2) it accommodates the overlapping of some key schizophrenic symptoms with other psychiatric conditions involving dissociation (thereby acknowledging the existence of both shared and distinguishing symptoms); and (3) it integrates a diversity of neurocognitive, neurobiological, and psychosocial (eg, the influence of trauma and culture) findings into a coherent but multi-factorial neuropsychological account.

An adequate model of schizophrenia may, then, need to postulate shared disturbances of core-self experiences that follow several distinct pathways, and occur in various forms. Such a model is preferable to uni-dimensional alternatives—whether of schizophrenia or of ipseity-disturbance—given its ability to account for the distinctive yet varying types of experiential and neurocognitive abnormalities found in research on schizophrenia.

Supplementary Material

Supplementary data are available at Schizophrenia Bulletin online.