When words and pictures come alive: Relating the modality of intrusive thoughts to modalities of hypnagogic/hypnopompic hallucinations

Hypnagogic and hypnopompic (H&H) hallucinations are those experienced on the borders of sleep and waking. Intrusive thoughts have been proposed to relate to the occurrence of such experiences. In a sample of students (N = 299), the present study investigated the relation between auditory and felt-presence H&H experiences, and specific modalities of intrusive thought (auditory and visual) whilst controlling for age, gender, depression, anxiety and thought suppression. The psychometric properties of the Durham Hypnagogic and Hypnopompic Hallucinations Questionnaire (DHQ) were also examined. Exploratory (N = 299) and, in a second sample, confirmatory (N = 502) factor analyses showed good internal and test-retest reliability for the auditory and felt-presence subscales of the DHQ, but not for the visual subscale. Regression analyses indicated that the sole predictor of auditory H&H hallucinations was intrusive auditory imagery, and the sole predictor of felt-presence H&H experiences was intrusive visual imagery. Explanations for these findings are considered and implications for future research are discussed.     

Intrusive thoughts and auditory hallucinations: a comparative study of intrusions in psychosis

Several theories of auditory hallucinations implicate the involvement of intrusive thoughts and other theories suggest that the interpretation of voices determines the distress associated with them. This study tested the hypotheses that patients who experience auditory hallucinations will experience more intrusive thoughts and be more distressed by them and interpret them as more uncontrollable and unacceptable than the control groups. It also examines whether the interpretation of hallucinations is associated with the distress caused by them and whether there are differences in the way that patients respond to and interpret their thoughts and voices. A questionnaire examining the frequency of intrusive thoughts and the reactions to them was administered to a group of patients with a diagnosis of schizophrenia who experienced auditory hallucinations, a psychiatric control group and a non-patient control group. In addition, the patients in the first group completed a similar questionnaire in relation to their voices. Analyses of covariance showed that patients who experienced auditory hallucinations had more intrusive thoughts than the control groups and that they found their intrusive thoughts more distressing, uncontrollable and unacceptable than the control groups. Correlational analyses revealed that patients' interpretations of their voices were associated with the measures of distress in relation to them. Repeated measures analyses of covariance found no differences between thoughts and voices on the dimensions assessed. The theoretical and clinical implications of these findings are discussed.     

The illusion of reality: a review and integration of psychological research on hallucinations

Hallucinations are among the most severe and puzzling forms of psychopathology. Although usually regarded as first-rank symptoms of schizophrenia, they are found in a wide range of medical and psychiatric conditions. Moreover, a substantial minority of otherwise normal individuals report hallucinatory experiences. The purpose of this article is to review the considerable research into the cognitive mechanisms underlying (particularly psychotic) hallucinations that has been carried out and to integrate this research within a general framework. The available evidence suggests that hallucinations result from a failure of the metacognitive skills involved in discriminating between self-generated and external sources of information. It is likely that different aspects of these skills are implicated in different types of hallucinatory experiences. Further research should focus on specific metacognitive deficits associated with different types of hallucinations and on treatment strategies designed to train hallucinators to reattribute thoughts to themselves.     

Metacognitions in patients with hallucinations and obsessive-compulsive disorder: the superstition factor

On the basis of the analogy between intrusive thoughts and auditory hallucinations established by Morrison et al. [(1995). Intrusive thoughts and auditory hallucinations: a cognitive approach. Behavioural and Cognitive Psychotherapy, 23, 265-280], the present work compares the metacognitive beliefs and processes of five groups of patients (current hallucinators, never-hallucinated people with a diagnosis of schizophrenia, recovered hallucinators, obsessive-compulsive disorder (OCD) patients, and a clinical control group) and a non-clinical group. The results show that of the five metacognitive factors considered in this study, two were found to be different in the current hallucinators group in comparison to any other group in the design. Likewise, it is found that the metacognitive beliefs of the current hallucinators coincide with those of the OCD patients in various factors, particularly that relating to superstition, and this is interpreted as lending support to the model of Morrison et al. (1995). Furthermore, the results are discussed in the light of existing research on Thought-Action Fusion, stressing the role that may be played by superstitious beliefs and magical thinking in auditory hallucinations and OCD.     

An inter-subjective multi-factorial model of auditory verbal hallucinations in schizophrenia

Auditory verbal hallucinations (AVHs) are perceptive-like experiences happening without appropriate stimuli that in individuals with schizophrenia very often feature distressing contents. AVH frequently interfere with social relationships or result in dangerous behaviours. We hypothesize that in schizophrenia several vulnerability factors, especially when a subject is engaged in real or represented interpersonal transactions, lead to the appearance of AVHs, and favour their self-perpetuation over time. We analyse the different psychological factors that, according to empirical studies and clinical experience with persons with schizophrenia, seem involved in the genesis of AVHs. Several vulnerability factors appear to interact with situational ones to trigger AVHs: a) a facilitation of neural transmission from the premotor regions to the perceptual ones; b) a difficulty attuning with others, c) interpersonal schemas, provoking emotional suffering, intrusive thoughts and rumination; d) metacognitive dysfunctions. Once AVHs have appeared, further factors promote their perpetuation over time: a) cognitive factors like ruminative processing on AVHs, b) metacognitive beliefs about AVHs. An integrated theoretical model of AVHs is described and ideas for its empirical testing are suggested.     

Sleep deprivation and hallucinations. A qualitative study of military personnel

Much anecdotal evidence suggests that sleep deprivation not only impairs performance, but also brings about other extraordinary effects like hallucinations. However, knowledge about how sleep deprivation may trigger hallucinations is limited. To qualitatively describe hallucinatory experiences during sleep deprivation 12 male military officers from the Norwegian Armed Forces who all had experienced at least one sleep loss-induced hallucinatory experience were recruited. Data were collected and analyzed by semi-structured interviews and thematic analysis. This resulted in the identification of three distinct main themes: (1) Modalities, (2) circumstances/triggers and (3) reactions to hallucinations. Hallucinations were experienced in several modalities (visual, auditory and multi-modality), although visual hallucinations seemed to dominate. Typical reported circumstances/triggers were sleep loss, physical exhaustion, time-of-day, low calorie intake, mental exhaustion and lack of external stimuli (low sensory and social input, boring situations, and monotonous activity). Negative emotions were dominant during the hallucinatory episodes. Often some reasoning and checking on behalf of the officers were necessary to differentiate between real percepts and hallucinations. In some cases the hallucinations caused erroneous actions. Retrospectively, most officers viewed their hallucinatory experiences in light of positive emotions and several emphasized having learned something from them. The results are discussed in relation to the existing literature and suggestions for future studies are outlined.     

On some types of hallucinatory experience

There are types of non-visual hallucinatory experience which occur in the psychoses other than those which have a critical and derogatory content. Wish-fulfilment plays an important part in the formation of the content of these hallucinations. In others, ‘persecutory’ anxiety also occurs. A comparison is made between hallucinatory and dream content. An hypothesis is presented to account for the perceptual quality of these hallucinatory experiences. The therapeutic implications of these considerations concludes this presentation.     

Rumination, reflection, intrusive thoughts, and hallucination-proneness: Towards a new model

Although rumination has been proposed to play an important role in the creation of hallucinations, direct empirical tests of this proposal have not yet been performed. Employing a distinction between ruminative and reflective self-consciousness, we set out to test a new model of the relations among rumination, reflection, intrusive thoughts, thought suppression, social anxiety, and hallucination-proneness. This model proposed that rumination would be related to hallucination-proneness through the mediating variable of intrusive thoughts, but that reflection would not be related to hallucination-proneness. The model was tested in a student population (N = 296) using path analyses. A modified version of the model was found to be a good fit to the data, once a direct path from reflection to hallucination-proneness had been added. As hypothesized, rumination was related to hallucination-proneness only indirectly, through the mediating variable of intrusive thoughts. Implications for interventions and future directions for research are considered.     

Obsessive intrusive thoughts in nonclinical subjects. Part I. Content and relation with depressive, anxious and obsessional symptoms

The present study reports on the development and preliminary validation of a 52 item self-report instrument designed to assess intrusive thoughts, images and impulses that are similar to the aggressive, sexual and disease-related thinking characteristic of clinical obsessions. Two hundred and ninety-three students completed the Obsessive Intrusions Inventory (OII) as well as standard self-report measures of negative cognitions and obsessive, anxious and depressive symptoms. Regression analysis revealed that intrusive thinking was a significant and unique predictor of obsessional but not anxious or depressive symptoms. Furthermore, intrusive thinking showed a moderate correlation with anxious but not depressive cognitions. The results indicate that the intrusive thoughts assessed by the OII are distinct from other forms of negative thinking and may, in fact, constitute an analogue form of clinical obsessions in nonclinical populations.     

The intuitive case for naïve realism

Naïve realism, the view that perceptual experiences are irreducible relations between subjects and external objects, has intuitive appeal, but this intuitive appeal is sometimes thought to be undermined by the possibility of certain kinds of hallucinations. In this paper, I present the intuitive case for naïve realism, and explain why this intuitive case is not undermined by the possibility of such hallucinations. Specifically, I present the intuitive case for naïve realism as arguing that the only way to make sense of the phenomenal character associated with perceptual experiences is by means of a naïve realist ontology. I then explain why this intuitive argument is not undermined by the possibility of hallucinatory experiences that possess the phenomenal character associated with perceptual experiences but, being hallucinations, do not have the ontological nature specified by naïve realism.     

Connecting neurosis and psychosis: the direct influence of emotion on delusions and hallucinations

Diagnostic classification systems contain a core divide between neurosis and psychosis, leading to their separate study and treatment. The basis for the separation of the disorders is outlined and reassessed. It is argued that the empirical evidence does not support such a sharp distinction between neurosis and psychosis. The frequent occurrence of emotional disorder prior to and accompanying psychosis indicates that neurosis contributes to the development of the positive symptoms of psychosis. Psychological theories and experimental evidence concerning the influence of emotion on the content and form of delusions and hallucinations are therefore reviewed. It is argued that in many cases delusions are a direct representation of emotional concerns, and that emotion contributes to delusion formation and maintenance. The content of hallucinations less often directly expresses the emotional concerns of the individual, but emotion can trigger and contribute to the maintenance of hallucinatory phenomena, although how this occurs is not well understood. It is concluded that study needs to be made of the interaction between psychotic and neurotic processes in the development of delusions and hallucinations, and that neurotic and psychotic disorders may have common maintenance processes.     

Hallucinations in the psychotic state: Psychoanalysis and the neurosciences compared

In this contribution, which takes account of important findings in neuroscientific as well as psychoanalytic research, the authors explore the meaning of the deep‐going distortions of psychic functioning occurring in hallucinatory phenomena. Neuroscientific studies have established that hallucinations distort the sense of reality owing to a complex alteration in the balance between top‐down and bottom‐up brain circuits. The present authors postulate that hallucinatory phenomena represent the outcome of a psychotic's distorted use of the mind over an extended period of time. In the hallucinatory state the psychotic part of the personality uses the mind to generate auto‐induced sensations and to achieve a particular sort of regressive pleasure. In these cases, therefore, the mind is not used as an organ of knowledge or as an instrument for fostering relationships with others. The hallucinating psychotic decathects psychic (relational) reality and withdraws into a personal, bodily, and sensory space of his own. The opposing realities are not only external and internal but also psychic and sensory. Visual hallucinations could thus be said to originate from seeing with the ‘eyes’ of the mind, and auditory hallucinations from hearing with the mind's ‘ears’. In these conditions, mental functioning is restricted, cutting out the more mature functions, which are thus no longer able to assign real meaning to the surrounding world and to the subject's psychic experience. The findings of the neurosciences facilitate understanding of how, in the psychotic hallucinatory process, the mind can modify the working of a somatic organ such as the brain.     

Husserl and externalism

It is argued that Husserl was an “externalist” in at least one sense. For it is argued that Husserl held that genuinely perceptual experiences—that is to say, experiences that are of some real object in the world—differ intrinsically, essentially and as a kind from any hallucinatory experiences. There is, therefore, no neutral “content” that such perceptual experiences share with hallucinations, differing from them only over whether some additional non-psychological condition holds or not. In short, it is argued that Husserl was a “disjunctivist”. In addition, it is argued that Husserl held that the individual object of any experience, perceptual or hallucinatory, is essential to and partly constitutive of that experience. The argument focuses on three aspects of Husserl’s thought: his account of intentional objects, his notion of horizon, and his account of reality.     

Appraisals of obsessional thoughts in normal samples

Cognitive theories of obsessive-compulsive disorder (OCD) posit that appraisals about the significance of thoughts are critical in the development and persistence of obsessions. Rachman [(1997). A cognitive theory of obsessions. Behaviour Research and Therapy, 35, 793-802.] proposes that appraisals of unwanted thoughts distinguish clinical obsessions from normal intrusive thoughts; thoughts appraised as important and personally significant are expected to be upsetting and recur. Appraisals are also expected to be related to symptoms of OCD. To explore the features of normal appraisals of obsession-like thoughts, nonclinical participants in two studies rated the personal significance of intrusive thoughts portrayed in vignettes containing prototypical themes associated with primary obsessions: aggressive, sexual, and blasphemous thoughts. Unwanted intrusive thoughts that were described as occurring more frequently were appraised as more personally significant, but participants appraised these socially unacceptable thoughts similarly whether they imagined having personally experienced them or a friend confiding about having experienced them. Appraisals in both studies were related to subclinical OC symptoms and OC beliefs.     

Laterality effects in perceived spatial location of hallucination-like voices

Aydin and colleagues reported a reversal of physiological 'right-ear advantage' in a group of right-handed patients with schizophrenia, using an auditory acuity test. In schizophrenia, auditory hallucinations may appear to be spatially located inside or outside the patient's head. Here we show, using virtual acoustic space techniques, that normal right-handed subjects have a right-ear advantage for correctly locating the 'source' of hallucination-like voices as from either inside or outside the head. We propose a model for understanding lateralised, external hallucinations in schizophrenia based upon reversal of normal cortical asymmetry for auditory spatial processing.     

Sense of agency over thought: external misattribution of thought in a memory task and proneness to auditory hallucination

Previous studies have suggested that auditory hallucination is closely related to thought insertion. In this study, we investigated the relationship between the external misattribution of thought and auditory hallucination-like experiences. We used the AHES-17, which measures auditory hallucination-like experiences in normal, healthy people, and the Deese–Roediger–McDermott paradigm, in which false alarms of critical lure are regarded as spontaneous external misattribution of thought. We found that critical lures elicited increased the number of false alarms as AHES-17 scores increased and that scores of AHES-17 predicted the rate of false memory of critical lures. Furthermore, we revealed that the relationship between AHES-17 scores and the rates of false alarms to critical lures was strictly linear. Therefore, it might be said that individual differences in auditory hallucination-like experiences are highly related to the external misattribution of thought. We discussed these results from the perspective of the sense of agency over thought.     

Context binding and hallucination predisposition

Patients with schizophrenia and current auditory hallucinations exhibit a combination of deficits in context binding and intentional inhibition. Hallucinations also occur in the general population suggesting an underlying continuity of causal mechanisms, however, these experiences may also differ (e.g., in frequency), indicating some differences in aetiology. The aim of this study was to examine the frequency of hallucinatory experiences in healthy young adults and to assess whether difficulties in context binding characterize individuals highly predisposed to hallucinations. A modified version of the Launay–Slade hallucination scale-revised, including an assessment of the frequency of hallucination experiences, was completed by 615 undergraduates from which sub-samples of high (n = 25) and low (n = 27) scorers were drawn. Context memory ability was assessed using a voice–location binding task. The results showed that the frequency of hallucinations in high LSHS-R scorers was much less than that previously reported for individuals with schizophrenia. Furthermore, no group differences in context memory binding were observed, nor any association between hallucination frequency and context binding difficulties. The continuity model of hallucinations may overlook some important differences in hallucinatory experiences in the general population versus psychosis.     

The monologue of the double: Allocentric reduplication of the own voice alters bodily self-perception

During autoscopic phenomena, people perceive a double of themselves in extrapersonal space. Such clinical allocentric self-experiences sometimes co-occur with auditory hallucinations, yet experimental setups to induce similar illusions in healthy participants have generally neglected acoustic cues. We investigated whether feeling the presence of an auditory double could be provoked experimentally by recording healthy participants’ own versus another person’s voice and movements using binaural headphones from an egocentric (the participants' own) and an allocentric (a dummy head located elsewhere) perspective. When hearing themselves allocentrically, participants reported feeling a self-identified presence extracorporeally, an arguably distinct quality of autoscopy. Our results suggest that participants without hallucinatory experiences localized their own voice closer to themselves compared to that of another person. Explorative findings suggest that distinct patterns for hallucinators should be further investigated. This study suggests a successful induction of the feeling of an acoustic doppelganger, bridging clinical phenomena and experimental work.     

A verbal behavior analysis of auditory hallucinations

A review of recent research on the non-medical control of auditory hallucinations is presented. It is suggested that the decreases in hallucinatory behavior obtained in studies using aversive contingencies may be attributable to the disruption of the chains of behavior involved. The results of several additional studies are interpreted as indicating that methods of stimulus control and the use of incompatible behaviors may be effective in reducing the rate of auditory hallucinations. Research relating auditory hallucinations to subvocalizations is presented in support of the view that hallucinatory phenomena are sometimes related to the subject's own vocal productions. Skinner's views (1934, 1936, 1953, 1957, 1980) are then presented as possible explanations of some hallucinatory behavior. It is suggested that some auditory hallucinations consit of the mishearing of environmental and physiological stimuli as voices in a fashion similar to that which Skinner observed in his work with the verbal summator. The maintenance of long chains of such responses may be largely attributable to self-intraverbal influences (such as are present during automatic writing). With some auditory hallucinations, this progression involves first mishearing ambiguous stimuli as voices and then attributing the voices to some cause (e.g., insanity, the television, radio, or God). Later, the frequent and ongoing chains of such behavior may contaminate other verbal responses. Such verbal behavior may be parasitic on "normal verbal behavior" (and hence, not directly dependent on consquences for maintenance), may be cued by various stimuli (including respiration), and may interfere with other covert and overt behavior. Several studies to investigate this view are presented. It is hoped that such research will lead to a better understanding of the major issues involved in the etiology and treatment of auditory hallucinations in particular and perhaps of psychosis in general.     

Sense of agency over speech and proneness to auditory hallucinations: The reality-monitoring paradigm

This study investigated the effects of imagining speaking aloud, sensorimotor feedback, and auditory feedback on respondents' reports of having spoken aloud and examined the relationship between responses to “spoken aloud” in the reality-monitoring task and the sense of agency over speech. After speaking aloud, lip-synching, or imagining speaking, participants were asked whether each word had actually been spoken. The number of endorsements of “spoken aloud” was higher for words spoken aloud than for those lip-synched and higher for words lip-synched than for those imagined as having been spoken aloud. When participants were prevented by white noise from receiving auditory feedback, the discriminability of words spoken aloud decreased, and when auditory feedback was altered, reports of having spoken aloud decreased even though participants had actually done so. It was also found that those who have had auditory hallucination-like experiences were less able than were those without such experiences to discriminate the words spoken aloud, suggesting that endorsements of having “spoken aloud” in the reality-monitoring task reflected a sense of agency over speech. These results were explained in terms of the source-monitoring framework, and we proposed a revised forward model of speech in order to investigate auditory hallucinations.