Models Of Auditory Verbal Hallucinations Research Articles

Explications cognitives des hallucinations acoustico-verbales dans la schizophrénie : un article de synthèse de la littérature scientifique

AimsOur article consists in both analysis and synthesis of contemporary cognitive models of auditory verbal hallucinations (AVHs) in schizophrenia. Our work is based on the analysis of the scientific literature including original articles, literature reviews as well as meta-analysis. MethodologyIn order to identify the most pertinent studies in the electronic search, the three following databases were systematically searched: PubMed, PsycINFO and MEDLINE. For both the analysis and synthesis we selected original articles, literature reviews as well as meta-analysis referring to any cognitive explanation of the auditory hallucinatory experience in schizophrenia. A cognitive model of auditory hallucinations refers to any incorporation of cognitive frameworks and explanations in one's conceptualization of the hallucinatory phenomenon in schizophrenia. We also focused our work on past conceptualization of auditory hallucinations in order to explain the development and the contribution of current cognitive models in the understanding of the onset and the maintaining of AVHs. After a brief review of clinical characteristics and historical conceptualization of auditory verbal hallucinations, contemporary explanations were presented in the area of schizophrenia. These explanations referred to researches into cognitive psychopathology including metacognitive as well as neuroimaging studies. ResultsThe examination of scientific literature highlighted the complexity of AVHs through multifactorial explanations here mostly explained by cognitive and metacognitive deficits. We synthesized former conceptualizations of AVHs, which were sustained on mechanistic or sensory explanations. Esquirol, Baillarger and Briere de Boismont were the first as conceiving AVHs as a perception disorder and introduced the idea that auditory hallucinations resulted from a failure to control one's memories/fantasies. Later, Broca and Wernicke discovered auditory areas in the human brain implicated in language comprehension and production. AVHs began to be conceptualized by the scientific world as being mechanistically brain-related. Sigmund Freud was among the first to study the meaning of AVHs, a domain still being investigated by todays cognitive sciences. More recently, neuroimaging studies allowed the validation of these sensory explanations in considering the onset of AVHs through the deficit of cortical and subcortical areas implicated in the process of languages (e.g. Broca and Wernicke areas) and emotions (e.g. limbic system, amygdala, hippocampus). At a more mechanistic level, contemporary cognitive models of AVHs explained AVHs as an intrusive verbal representation into the awareness which is non-inhibited (i.e. deficit in intentional inhibition) and also non-recognized as one's own experience (i.e. deficit in source monitoring, planning and metacognition), or even attributed to an external source (attribution bias). In terms of inhibitory control, inhibition is a basic cognitive mechanism defined as a collection of processes that allows the suppression of previously activated cognitive contents and the clearing of irrelevant actions or attention from consciousness. Intentional inhibition is effortful and occurs when an individual deliberately suppresses the activation of an item after deciding it is irrelevant. Theoretical support for the suggestion that an inhibitory failure is involved in AVHs in schizophrenia arises from studies that have shown that a failure in inhibition results in intrusive thoughts from long-term memory. Recent findings also found that individuals with AVHs in schizophrenia demonstrated an impaired source monitoring. In episodic memory research, a distinction was made between content (an event) and context (e.g. source or temporal characteristics of an event) information. The context of memories provides cues that allow an individual to differentiate one memory from other memories. AVHs are conceptualized as a failure to access the contextual cues that would allow voice-hearer to form an intact representation of events in memories. Regarding planning, AVHs refer to the intrusion of unwanted memories into the inner speech that are not recognized from one's own representation. Previous cognitive theories highlighted the important role played by metacognitive skills and belief (i.e. thinking about one's thinking) in the explanation of AVHs. Finally, the external attribution bias was extensively studied over the last three decades and refers to the tendency to attribute negative events (situational or cognitive) to an external source. In this framework, AVHs refer to intrusive thoughts externally attributed to a voice. ConclusionFor more than one century, scientific discoveries in (bio)medical science have allowed the validation of former sensory and mechanistic explanations of AVHs. Nevertheless, many explanatory models account for the way AVHs are maintained (source monitoring, deficit in planning, externalizing bias), while they scarcely expose how they are triggered (intrusive thoughts, deficit in inhibition). The relation between AVHs and intrusive thoughts still remain unclear, and further studies are needed for the understanding of a potential causal relationship.

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.

Preliminary Evidence for the Cognitive Model of Auditory Verbal Hallucinations in Youth With Borderline Personality Disorder.

Objectives: This is the first study to explore cognitive, emotional, and behavioral responses to voices in youth with borderline personality disorder (BPD) compared with those with schizophrenia spectrum disorder (SZ), and to examine if negative appraisals of voices predict depression and anxiety across the groups. Methods: The sample comprised 43 outpatients, aged 15–25 years, who reported auditory verbal hallucinations (AVH) and were diagnosed with either Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) BPD or SZ. Data were collected using the Psychotic Symptom Rating Scales, the revised Beliefs About Voices Questionnaire, the Voice Rank Scale, and the Depression Anxiety Stress Scale. Results: Youth with BPD did not differ from youth with SZ in beliefs about the benevolence or malevolence of voices. Youth with BPD appraised their voices as more omnipotent and of higher social rank in relation to themselves, compared with youth with SZ. In both diagnostic groups, beliefs about malevolence and omnipotence of voices were correlated with more resistance toward voices, and beliefs about benevolence with more engagement with voices. In addition, perceiving the voices as being of higher social rank than oneself and negative voice content were both independent predictors of depression, irrespective of diagnostic group. In contrast, negative appraisals of voices did not predict anxiety after adjusting for negative voice content. Conclusions: This study replicated the link between negative appraisals of voices and depression that has been found in adults with SZ in a mixed diagnostic youth sample. It, thus, provides preliminary evidence that the cognitive model of AVH can be applied to understanding and treating voices in youth with BPD.

Active Inference and Auditory Hallucinations.

Auditory verbal hallucinations (AVH) are often distressing symptoms of several neuropsychiatric conditions, including schizophrenia. Using a Markov decision process formulation of active inference, we develop a novel model of AVH as false (positive) inference. Active inference treats perception as a process of hypothesis testing, in which sensory data are used to disambiguate between alternative hypotheses about the world. Crucially, this depends upon a delicate balance between prior beliefs about unobserved (hidden) variables and the sensations they cause. A false inference that a voice is present, even in the absence of auditory sensations, suggests that prior beliefs dominate perceptual inference. Here we consider the computational mechanisms that could cause this imbalance in perception. Through simulation, we show that the content of (and confidence in) prior beliefs depends on beliefs about policies (here sequences of listening and talking) and on beliefs about the reliability of sensory data. We demonstrate several ways in which hallucinatory percepts could occur when an agent expects to hear a voice in the presence of imprecise sensory data. This model expresses, in formal terms, alternative computational mechanisms that underwrite AVH and, speculatively, can be mapped onto neurobiological changes associated with schizophrenia. The interaction of action and perception is important in modeling AVH, given that speech is a fundamentally enactive and interactive process—and that hallucinators often actively engage with their voices.

The Representation of Agents in Auditory Verbal Hallucinations.

Current models of auditory verbal hallucinations (AVHs) tend to focus on the mechanisms underlying their occurrence, but often fail to address the content of the auditory experience. In other words, they tend to ask why there are AVHs at all, instead of asking why, given that there are AVHs, they have the properties that they have. One such property, which has been largely overlooked and which we will focus on here, is why the voices are often experienced as coming from (or being the voices of) agents, and often specific, individualised agents. In this article, we argue not only that the representation of agents is important in accurately describing many cases of AVH, but also that deeper reflection on what is involved in the representation of agents has potentially vital consequences for our aetiological understanding of AVH, namely, for understanding how and why AVHs come about.

Ketamine-Induced Hallucinations

Background: Ketamine, the NMDA glutamate receptor antagonist drug, is increasingly employed as an experimental model of psychosis in healthy volunteers. At subanesthetic doses, it safely and reversibly causes delusion-like ideas, amotivation and perceptual disruptions reminiscent of the aberrant salience experiences that characterize first-episode psychosis. However, auditory verbal hallucinations, a hallmark symptom of schizophrenia, have not been reported consistently in healthy volunteers even at high doses of ketamine. Sampling and Methods: Here we present data from a set of healthy participants who received moderately dosed, placebo-controlled ketamine infusions in the reduced stimulation environment of the magnetic resonance imaging (MRI) scanner. We highlight the phenomenological experiences of 3 participants who experienced particularly vivid hallucinations. Results: Participants in this series reported auditory verbal and musical hallucinations at a ketamine dose that does not induce auditory hallucination outside of the scanner. Conclusions: We interpret the observation of ketamine-induced auditory verbal hallucinations in the context of the reduced perceptual environment of the MRI scanner and offer an explanation grounded in predictive coding models of perception and psychosis - the brain fills in expected perceptual inputs, and it does so more in situations of altered perceptual input. The altered perceptual input of the MRI scanner creates a mismatch between top-down perceptual expectations and the heightened bottom-up signals induced by ketamine. Such circumstances induce aberrant percepts, including musical and auditory verbal hallucinations. We suggest that these circumstances might represent a useful experimental model of auditory verbal hallucinations and highlight the impact of ambient sensory stimuli on psychopathology.

The Spectra of Soundless Voices and Audible Thoughts: Towards an Integrative Model of Auditory Verbal Hallucinations and Thought Insertion

Patients with psychotic disorders experience a range of reality distortions. These often include auditory-verbal hallucinations (AVHs), and thought insertion (TI) to a lesser degree; however, their mechanisms and relationships between each other remain largely elusive. Here we attempt to establish a integrative model drawing from the phenomenology of both AVHs and TI and argue that they in fact can be seen as ‘spectra’ of experiences with varying degrees of agency and ownership, with ‘silent and internal own thoughts’ on one extreme and ‘fully external and clearly audible voices’ in the absence of a speaker on the other. We believe a spectral model will add emphasis to the continuity of experience and help to better understand how one type of psychotic symptom may interact with another, and put forward the argument that the experience of TI itself is not sufficient to classify as a delusion. In addition we aim to discuss some of the conceptual issues surrounding AVHs and TI with first-person accounts and current philosophical and neuropsychological theories in mind. We propose that the mechanisms behind AVHs and TI are more complex than source-monitoring deficits; indeed, to understand such phenomena one must appreciate that their very ‘existence’ and ‘reality’ as experienced by the individual have much deeper implications and meaning, both philosophically and clinically.

Verbal working memory deficits predict levels of auditory hallucination in first-episode psychosis

BackgroundAuditory verbal hallucinations are a characteristic symptom in schizophrenia. Recent causal models of auditory verbal hallucinations propose that cognitive mechanisms involving verbal working memory are involved in the genesis of auditory verbal hallucinations. Thus, in the present study, we investigate the hypothesis that verbal working memory is a specific factor behind auditory verbal hallucinations. MethodsIn the present study, we investigated the association between verbal working memory manipulation (Backward Digit Span and Letter–Number Sequencing) and auditory verbal hallucinations in a population study (N=52) of first episode psychosis. The degree of auditory verbal hallucination as reported in the P3-subscale of the PANSS interview was included as dependent variable using sequential multiple regression, while controlling for age, psychosis symptom severity, executive cognitive functions and simple auditory working memory span. ResultsMultiple sequential regression analyses revealed verbal working memory manipulation to be the only significant predictor of verbal hallucination severity. ConclusionsConsistent with cognitive data from auditory verbal hallucinations in healthy individuals, the present results suggest a specific association between auditory verbal hallucinations, and cognitive processes involving the manipulation of phonological representations during a verbal working memory task.

Stop, look, listen: the need for philosophical phenomenological perspectives on auditory verbal hallucinations

One of the leading cognitive models of auditory verbal hallucinations (AVHs) proposes such experiences result from a disturbance in the process by which inner speech is attributed to the self. Research in this area has, however, proceeded in the absence of thorough cognitive and phenomenological investigations of the nature of inner speech, against which AVHs are implicitly or explicitly defined. In this paper we begin by introducing philosophical phenomenology and highlighting its relevance to AVHs, before briefly examining the evolving literature on the relation between inner experiences and AVHs. We then argue for the need for philosophical phenomenology (Phenomenology) and the traditional empirical methods of psychology for studying inner experience (phenomenology) to mutually inform each other to provide a richer and more nuanced picture of both inner experience and AVHs than either could on its own. A critical examination is undertaken of the leading model of AVHs derived from phenomenological philosophy, the ipseity disturbance model. From this we suggest issues that future work in this vein will need to consider, and examine how interdisciplinary methodologies may contribute to advances in our understanding of AVHs. Detailed suggestions are made for the direction and methodology of future work into AVHs, which we suggest should be undertaken in a context where phenomenology and physiology are both necessary, but neither sufficient.

From mind-pops to hallucinations? A study of involuntary semantic memories in schizophrenia

Involuntary semantic memories or mind-pops consist of isolated fragments of one's semantic knowledge (e.g., a word or a sentence, proper name, image or a melody) that come to mind unexpectedly, without any deliberate attempt to recall them. They can be experienced as alien and uncontrollable, and may share some phenomenological similarities with hallucinations. The aim of the present study was to investigate the nature and frequency of mind-pops in people with schizophrenia (N=37), as well as clinically depressed (N=31) and non-clinical controls (N=31). Results showed that schizophrenia patients reported experiencing mind-pops more frequently than both depressed and non-clinical controls. Schizophrenia patients also reported a wider range of different types of mind-pops than non-clinical controls. The depressed group did not differ from non-clinical controls in the frequency and range of mind-pops, indicating that mind-pops are not characteristic of clinical populations in general, but may be particularly prevalent in patients with schizophrenia. The possible implications of this finding to current models of auditory verbal hallucinations are discussed and the need for future research in this area is emphasized.

Subjective Loudness and Reality of Auditory Verbal Hallucinations and Activation of the Inner Speech Processing Network

One of the most influential cognitive models of auditory verbal hallucinations (AVH) suggests that a failure to adequately monitor the production of one's own inner speech leads to verbal thought being misidentified as an alien voice. However, it is unclear whether this theory can explain the phenomenological complexity of AVH. We aimed to assess whether subjective perceptual and experiential characteristics may be linked to neural activation in the inner speech processing network. Twenty-two patients with schizophrenia and AVH underwent a 3-T functional magnetic resonance imaging scan, while performing a metrical stress evaluation task, which has been shown to activate both inner speech production and perception regions. Regions of interest (ROIs) comprising the putative inner speech network were defined using the Anatomical Automatic Labeling system. Correlations were calculated between scores on the "loudness" and "reality" subscales of the Auditory Hallucination Rating Scale (AHRS) and activation in these ROIs. Second, the AHRS subscales, and general AVH severity, indexed by the Positive and Negative Syndrome Scale, were correlated with a language lateralization index. Louder AVH were associated with reduced task-related activity in bilateral angular gyrus, anterior cingulate gyrus, left inferior frontal gyrus, left insula, and left temporal cortex. This could potentially be due to a competition for shared neural resources. Reality on the other hand was found to be associated with reduced language lateralization. Strong activation of the inner speech processing network may contribute to the subjective loudness of AVH. However, a relatively increased contribution from right hemisphere language areas may be responsible for the more complex experiential characteristics, such as the nonself source or how real AVH are.

S28-04 Inner speech-based models of auditory verbal hallucinations: What can they explain?

The term auditory verbal hallucination (AVH) covers a diverse phenomenological experience. One model of AVHs proposes they result from self-monitoring deficits causing inner speech to be experienced as alien. The experimental evidence for such a model is briefly summarised. The fit of inner speech models with the phenomenology of AVHs is then critically examined. The form, function, and development of private and inner speech is discussed, and contrasted with the phenomenology of a range of AVHs. It is argued that only a subset of AVHs are phenomenologically consistent with inner speech models. Implications for the study of AVHs are discussed.

Do we need multiple models of auditory verbal hallucinations? Examining the phenomenological fit of cognitive and neurological models.

The causes of auditory verbal hallucinations (AVHs) are still unclear. The evidence for 2 prominent cognitive models of AVHs, one based on inner speech, the other on intrusions from memory, is briefly reviewed. The fit of these models, as well as neurological models, to the phenomenology of AVHs is then critically examined. It is argued that only a minority of AVHs, such as those with content clearly relating to verbalizations experienced surrounding previous trauma, are consistent with cognitive AVHs-as-memories models. Similarly, it is argued that current neurological models are only phenomenologically consistent with a limited subset of AVHs. In contrast, the phenomenology of the majority of AVHs, which involve voices attempting to regulate the ongoing actions of the voice hearer, are argued to be more consistent with inner speech-based models. It is concluded that subcategorizations of AVHs may be necessary, with each underpinned by different neurocognitive mechanisms. The need to study what is termed the dynamic developmental progression of AVHs is also highlighted. Future empirical research is suggested in this area.

Inner speech models of auditory verbal hallucinations: Evidence from behavioural and neuroimaging studies

A range of psychological theories have been proposed to account for the experience of auditory hallucinations in patients with psychosis. Influential amongst these theories are those implicating the defective monitoring of inner speech. Furthermore, self-monitoring and inner speech models have been the most studied using functional imaging. The aim of this article is to review the behavioural and neuroimaging evidence for the impaired monitoring of inner speech in patients who experience auditory verbal hallucinations. A comprehensive literature search was conducted for research investigating inner speech and cognitive self-monitoring models of auditory hallucinations in patients with schizophrenia. The evidence is critically discussed and directions for future investigations are suggested.

Thought as action: Inner speech, self-monitoring, and auditory verbal hallucinations

Passivity experiences in schizophrenia are thought to be due to a failure in a neurocognitive action self-monitoring system (NASS). Drawing on the assumption that inner speech is a form of action, a recent model of auditory verbal hallucinations (AVHs) has proposed that AVHs can be explained by a failure in the NASS. In this article, we offer an alternative application of the NASS to AVHs, with separate mechanisms creating the emotion of self-as-agent and other-as-agent. We defend the assumption that inner speech can be considered as a form of action, and show how a number of previous criticisms of applying the NASS to AVHs can be refuted. This is achieved in part through taking a Vygotskian developmental perspective on inner speech. It is suggested that more research into the nature and development of inner speech is needed to further our understanding of AVHs.

Spence, S., & David, A. (Eds.). (2004). Voices in the brain: The cognitive neuropsychiatry of auditory verbal hallucinations. By Sukhi S. Shergill

S.A. Spence - Voices in the Brain. G. Cockshutt - Choices for Voices: A Voice Hearer's Perspective on Hearing Voices. P. Bracken, I. Leudar, P. Thomas - Hearing Voices: A Phenomenological-Hermeneutic Approach. T. Wykes - Psychological Treatment for Voices in Psychosis. M.L. Seal, A. Aleman, P.K. McGuire - Compelling Imagery, Unanticipated Speech and Deceptive Memory: Neurocognitive Models of Auditory Verbal Hallucinations in Schizophrenia. P.W.R. Woodruff - Auditory Hallucinations: Insights and Questions from Neuroimaging. M.D. Hunter, Locating Voices in Space: A Perceptual Model for Auditory Hallucinations? A.S. David - The Cognitive Neuropsychiatry of Auditory Verbal Hallucinations: An Overview. T.J. Crow - Auditory Hallucinations as Primary Disorders of Syntax: An Evolutionary Theory of the Origins of Language.

Compelling imagery, unanticipated speech and deceptive memory: Neurocognitive models of auditory verbal hallucinations in schizophrenia

Introduction. The application of neurocognitive models to study schizophrenia has been influential in understanding the nature of this complex and heterogeneous disorder. However, a comprehensive and empirically validated account of auditory hallucinations remains elusive. The aim of this review was to critically assess the current evidence for specific neurocognitive deficits associated with auditory verbal hallucinations (AVHs) in schizophrenia.Methods. A systematic literature search was conducted of research involving three influential cognitive models of auditory hallucinations: those implicating dysfunction in auditory imagery, verbal self-monitoring, and episodic memory.Results. The findings of the review suggested that AVHs have been associated with impaired verbal self-monitoring, impaired memory for self-generated speech, heightened influence of top-down processing on perception, and an externalising response bias.Conclusions. On the basis of the findings of the review a multidimensional model of AVHs is proposed incorporating the identified cognitive deficits and biases.

Verbal self-monitoring and auditory verbal hallucinations in patients with schizophrenia.

Contemporary cognitive models of auditory verbal hallucinations propose that they arise through defective self-monitoring. We used a paradigm that engages verbal self-monitoring to investigate this theory in patients with schizophrenia. Ten patients with auditory verbal hallucinations and delusions (hallucinators), eight patients with delusions but no hallucinations (non-hallucinators), and 20 non-psychiatric control subjects were tested. Participants read single adjectives aloud, under the following randomized conditions: reading aloud; reading aloud with acoustic distortion of their own voice; reading aloud with alien feedback (someone else's voice); and reading aloud with distorted alien feedback. Immediately after articulating each word, participants identified the source of the speech they heard ('self'/'other'/'unsure'), via a button press. Response choice and reaction time were recorded. When reading aloud with distorted feedback of their own voice, patients in both groups made more errors than controls; they either misidentified its source or were unsure. Hallucinators were particularly prone to misattributing their distorted voice to someone else, and were more likely to make errors when the words presented were derogatory. Both patient groups made faster decisions than controls about the source of distorted or alien speech, but faster responses were only associated with errors in the former condition. Impaired verbal self-monitoring was evident in both hallucinators and non-hallucinators. As both groups had delusions, the results suggest an association between delusions and impaired judgements about ambiguous sensory stimuli. The specific tendency of hallucinators to misattribute their distorted voice to someone else may reflect impaired awareness of internally generated verbal material.