[Truncated abstract] Auditory hallucinations (AHs) are one of the most common symptoms of schizophrenia, and are associated with high levels of distress, functional impairment, and need for care. However, current understanding of the exact causes and thus treatment of AHs is still in its infancy. Recently, Badcock and colleagues proposed a cognitive dual-deficit model of AHs, which stipulates that intentional inhibition deficits underlie the intrusive and unintentional nature of AHs, while context memory binding deficits explain the source misattribution (Waters, Badcock, Michie, & Maybery, 2006). While this model seems to best explain the different features of AHs, the precise components of inhibitory control involved, and the evident role of negative affect in the production of AHs, have not been empirically examined. Thus, the first two aims of this thesis were to clarify the critical component(s) of inhibitory control specifically related to AHs, and to examine the relationships between negative affect (chiefly anxiety), AHs and inhibitory control. Finally, AHs are also commonly reported by individuals in the general population, consistent with a continuum approach to AHs. Accordingly, the third aim of this thesis was to investigate whether similar relationships exist between hallucinatory-type experiences, inhibitory processes and negative affect in both hallucination predisposition and schizophrenia. The first study presents the findings from two related investigations of hallucination predisposition. ... However, the study revealed a significant relationship between intentional inhibition and trait anxiety (which was independent of hallucination predisposition) allowing the possibility that more severe or longer lasting changes in anxiety may indeed exacerbate difficulties with intentional inhibition. The final study sought to determine whether the pattern of relationships between AHs, inhibitory impairments and anxiety in schizophrenia are similar to those found in hallucination predisposition. The same three cognitive tasks previously employed (ICIM, B-P, and DI) were administered to schizophrenia (N = 61) and healthy control (N = 34) participants. Schizophrenia participants overall exhibited difficulties intentionally resisting interference from distracting stimuli, however did not have difficulties [intentionally or unintentionally] inhibiting task-irrelevant memory traces. Consistent with the continuum approach, AHs were related only to difficulties with intentional inhibition, and these difficulties existed independently from anxiety (although anxiety was related to intentional inhibition) and were unrelated to other schizophrenia symptoms. Together, the studies support the first component of Badcock et al.'s dual-deficit model of AHs, with hallucinatory experiences in both hallucination predisposition and schizophrenia associated with specific intentional inhibition impairments. The findings also suggest that while anxiety may contribute to the production of AHs by exacerbating v existing intentional inhibition impairments, it is likely that anxiety has additional routes of influence. These findings provide strong support for the continuum approach to AHs. The implications of these findings and possible avenues for future research are discussed.

Texte remanié de: th. doct.--München--Universität, 2000. / Bibliogr. p. [455]-508.

The aim of this project was to study the phenomenology of auditory hallucinations in Indians. The sample investigated consisted of thirty adult Indian males domiciled in the Durban area, attending neuroclinics, who had been diagnosed as having suffered from a psychosis and who had experienced auditory hallucinations. The patients were examined by the author and in addition relevant data was extracted from their case files. This included religion, previous diagnosis, age at onset of illness and present age, mother tongue, language of daily usage, language of hallucinations, source of hallucinations, comprehensibi1ity of hallucinations, content of hallucinations, patient's initial reaction to hallucinations, time when hallucinations were experienced, media of transmission, direction of voices and whether the patient had consulted a traditional healer. The findings were that a significant majority of patients: 1) described their hallucinations as being voices coming from supernatural beings (84%). 2) did not attribute their hallucinations to being voices belonging to their deceased ancestors (88%). 3) did not attribute their hallucinations to voices which were being relayed by technical transmitting apparatuses (88%) . 4) diagnosed as suffering from schizophrenia initially, found their hallucinations to be distressful (89%) whereas 80% of the patients diagnosed as suffering from manic depressive psychosis found their hallucinations to be pleasant. 5) did not ascribe their hallucinations to animals (100%). 6) had visited a traditional healer (100%). Hallucinations were generally thought by the majority of patients to have occurred as a result of being possessed by spirits and that the possession had occurred following some "evil" done to them by enemies, rivals, or other persons who wanted the patient to come to harm. Their belief in spirits was derived both from religion and from folk-lore. Its connection with auditory hallucinations arose from the notion that evil spirits can invade human beings causing abnormal behaviour and also symptoms of mental illness including auditory hallucinations. All the patients had visited traditional healers presumably to exorcise the spirits that had possessed them. The Durban Indian community has been reported to be a deculturing community with many of its members adopting Western cultural attitudes and values. The following factors (religion, language grouping, and beliefs derived from folk-lore), specific to Indian culture, appear to have an important influence in shaping some aspects of the phenomenology of auditory hallucinations of psychotic Indian males. / Thesis (M.Med.)-University of Natal, Durban, 1985.

Access to abstract permanently restricted to Ball State community only / Access to thesis permanently restricted to Ball State community only / Department of Psychological Science

Thesis (M. Div.)--Talbot School of Theology, Biola University, 1992. / Includes bibliographical references (leaves [68-72]).

Thesis (M. Div.)--Talbot School of Theology, Biola University, 1992. / Includes bibliographical references (leaves [68-72]).

Schizophrenia (SZ) is a complex and chronic psychotic disorder that affects approximately 1% of the world's population and is associated with positive, negative, and cognitive symptoms. Auditory verbal hallucinations (AVHs) are a key symptom of SZ that cause functional impairments and distress. Despite antipsychotic medication treatments, 25% of patients experience medication resistant AVHs. Additional research into the underlying neuronal mechanisms of AVHs is needed to develop alternative treatments. The mismatch negativity (MMN) is an auditory event-related potential that represents pre-attentive detection of stimulus deviance. MMN deficits are prominent in SZ and are associated with greater AVH frequency. MMN deficits may also be related to qualitative features of AVHs, which have yet to be extensively assessed. The primary aim of this work was to assess differences in MMN features (amplitude and latency) between SZ patients and healthy controls (HCs) using two different versions of the MMN five deviant multi-feature task (pure tone and speech-based sounds). The second aim was to examine relationships between MMN features, clinical ratings of AVH severity (The Psychotic Symptom Rating Scale [PSYRATS] total score, Positive and Negative Syndrome Scale [PANSS] item 3 ["hallucinatory behaviour"]) and self-report measures of AVH features in SZ patients (i.e., the Beliefs About Voices Questionnaire-Revised [BAVQ-R], Voice Acceptance and Action Scale [VAAS] and the Voice Power Differential Scale [VPDS]), the latter has yet to be assessed. The secondary aim was to directly compare differences in the MMN responses between SZ and HC groups across the two tasks. Finally, exploratory aims included examining differences in MMN responses to low and high frequency and intensity deviants in the tone task and assessing differences in the MMN response between groups at the mastoid sites (TP9/TP10), where the polarity reversal of the MMN occurs. These more methodological aims have not been previously assessed, to our knowledge. The SZ group (n = 16) had significantly smaller MMN amplitudes to the frequency, gap and intensity deviants compared to the HC group (n = 17) in the MMN tone task. In the MMN speech task, the SZ group had significantly smaller MMN amplitudes to the frequency, intensity, vowel duration and consonant deviants compared to the HC group. The correlation analysis revealed that the most pronounced relation was a positive association between MMN amplitudes to the intensity deviant (tone task) and total scores on the VPDS (i.e., smaller/less negative MMN amplitudes were associated with higher VPDS scores). For the secondary analyses, the SZ group had smaller MMN amplitudes to the frequency deviant in both the tone and speech MMN tasks. Finally, the exploratory mastoid analysis in the tone task revealed that the SZ group had smaller MMN amplitudes to the frequency deviant at both mastoid sites. In the speech task, MMN amplitudes were larger at the left mastoid site (TP9) compared to the right mastoid site (TP10) across all deviant types. The HC group also had larger MMN amplitudes at the left mastoid site (TP9) compared to the SZ group. This study revealed MMN deficits in SZ patients across a variety of deviant types, including both pure tone deviants and speech-based deviants. MMN deficits were most pronounced for the frequency and intensity deviants across both tasks, suggesting that SZ patients with persistent AVHs may have more generalized deficits in the automatic processing of basic units of speech and pure tones, rather than impaired processing of specific acoustic features. Associations between MMN features and subjective measures of AVHs revealed that impaired processing of pure tone intensity deviants is related with a greater perceived "power" of the voice, impaired processing of speech-based frequency deviants is related to greater clinical AVH severity, and that impaired and less efficient processing of both vowel and pure tone deviants are related to a higher perceived hostility of the voice. This study adds valuable information to the literature regarding relationships between MMN features and subjective aspects of the AVH experience in SZ patients. Importantly, this work is novel as it is the first to directly compare MMN responses across two tasks (speech and sound) in SZ patients with persistent AVHs. This thesis emphasizes the importance of examining subjective aspects of the AVH experience in the context of the MMN to gather a more complete understanding of how AVHs are impacting brain responses.

No description available.

Hearing voices is a well researched experience, found in both schizophrenia and the general population. Previous research investigating the unusual experience has reinforced cognitive psychology concepts such as beliefs, power, core beliefs about the self, intent and identity. It has been suggested that these factors all mediate individual coping with the experience. Coping with voices is a clinically significant area of research pioneered by Romme and Escher and requires careful consideration. Kelly‘s Personal Construct Psychology and the repertory grid technique were used in the study to compare two ways of coping with voices: engaging and resisting coping. The groups were compared on the repertory grid measures of construed distance between the self and the voice, salience of the self and voice, and tightness of the overall construct system. In a sample of 18 voice hearers, the Beliefs about Voices Questionnaire- Revised (BAVQ-R), a measure of psychological distress (OQ45.2) and Kelly‘s repertory grid were administered. The study also used three case examples and content analysis of construct poles applied to the dominant voice and the self as coper to supplement the quantitative analysis with a more in-depth exploration. Resisting coping was found to be associated with a greater construed distance between the self and the voice, a more salient view of the voice, and a tighter construct system. However, neither resisting nor engaging coping was associated with psychological distress. In addition, voice malevolence was associated with distancing oneself from the voice, suggesting that distancing was an adaptive coping strategy used, possibly as a way to preserve selfhood. The study therefore added to the list of mediating factors between the voice hearing experience and the coping strategy adopted. As a result, the repertory grid showed some scope in assessing the three areas of interest. The findings suggest that clinically, voice hearers can best be supported by adopting the appropriate relational approach with the voice (closeness or distance), reducing the salience of the voice and moving through Kelly‘s Creativity and Experience Cycle.

Les hallucinations visuelles (HV) sont un symptôme psychotique commun retrouvé de manière transdiagnostique dans les troubles de la vision, les troubles neurologiques et les troubles psychiatriques. Les différents modèles cognitifs des HV s’accordent sur la présence d’une perturbation du traitement de l’information visuelle bottom-up et des processus tardifs top-down pour expliquer la survenue des HV. Dans un première partie de notre travail, nous avons étudié les caractéristiques communes entre les pathologies caractérisées par la présence d’HV et avons constaté que toutes présentent des anomalies structurales ou fonctionnelles de la rétine mais que peu d’études ont exploré le lien entre anomalies fonctionnelles de la rétine et HV. Nous avons ensuite étudié le fonctionnement de la rétine chez des patients souffrant de schizophrénie présentant ou non des HV. Nos résultats ont montré la présence d’anomalies fonctionnelles touchant le système des photorécepteurs et les cellules ganglionnaires de la rétine chez les patients souffrant de schizophrénie et des anomalies fonctionnelles du système des bâtonnets spécifiquement chez les patients présentant des HV. Les anomalies du traitement sensoriel sont une condition nécessaire mais insuffisante pour expliquer la survenue des HV. Ainsi nous avons exploré l’influence du traitement des émotions dans les HV, par une tâche d’amorçage émotionnel sur le traitement de stimuli ambigus chez des sujets sains prônes aux hallucinations et des patients souffrant de schizophrénie. Les premiers résultats intermédiaires présentés montrent en partie que la manipulation d'une amorce émotionnelle pourrait influencer la perception de stimuli ambigus chez les sujets sains prônes aux hallucinations. Ces arguments sont à confirmer par un nouveau protocole de recherche à adapter. Nos résultats nous permettent de discuter l’adaptation d’un modèle des HV dans la schizophrénie. / Visual hallucinations (VH) are a common psychotic symptom present in eye disease, neurological disorders and psychiatric disorders. Cognitive models of VH postulate the disruption of both bottom-up visual information processing and late top-down processes to explain the emergence of VH. In the first part of our work, we have reviewed the common characteristics between pathologies characterized by VH. We have found that structural or functional abnormalities of the retina were systematically present, but few studies have explored the link between these abnormalities and VH. Hence, we have explored the retinal functions in schizophrenia patients with or without VH. We have found photoreceptors and retinal ganglion cells abnormalities in patients with schizophrenia and abnormalities of the rod system specifically in patients with VH. Abnormalities of sensory processing are a necessary but insufficient condition to explain the occurrence of VH. Thus, we have explored the influence of emotion processing in healthy hallucinations prone subjects and schizophrenia patients in an emotional priming task requiring the treatment of ambiguous stimuli. We expose intermediate results which show that the manipulation of an emotional primer can influence the perception of ambiguous stimuli in healthy hallucinations prone subjects. These results need replications in a new research protocol. Our results allow us to discuss the adaptation of a model of VH in schizophrenia.