Cognitive processes in auditory hallucinations: attributional biases and metacognition

BACKGROUND: Cognitive models suggest that auditory hallucinations are experienced when mental events are misattributed to an external source; therefore, this study was designed to examine attributional biases in patients experiencing auditory hallucinations. The study also examined the role of metacognitive beliefs in the experience of auditory hallucinations, as some theories have implicated metacognition in the development and maintenance of auditory hallucinations. METHODS: Fifteen participants with a diagnosis of schizophrenia experiencing auditory hallucinations were compared with 15 non-hallucinating schizophrenics and 15 non-psychiatric control subjects on several measures, including an immediate source monitoring task and a questionnaire assessing metacognitive beliefs. RESULTS: Results indicated that patients experiencing hallucinations exhibited the predicted bias towards misattributing internal events to an external source, as measured by ratings of internality of responses in a word association task. All groups had lower perceived levels of internality and control for emotionally salient words, which provides further evidence for the importance of emotional content in hallucinations. Patients experiencing hallucinations were found to score higher than the other two groups on metacognitive beliefs about uncontrollability and danger and positive beliefs about worry. In addition, a logistic regression analysis showed that beliefs about uncontrollability and danger were predictive of whether subjects experienced auditory hallucinations or not. CONCLUSIONS: These results offer considerable support to cognitive bias models of auditory hallucinations, particularly those that implicate metacognition.     

Visual hallucinations in schizophrenia: Confusion between imagination and perception.

Objective: An association between hallucinations and reality-monitoring deficit has been repeatedly observed in patients with schizophrenia. Most data concern auditory/verbal hallucinations. The aim of this study was to investigate the association between visual hallucinations and a specific type of reality-monitoring deficit, namely confusion between imagined and perceived pictures. Method: Forty-one patients with schizophrenia and 43 healthy control participants completed a reality-monitoring task. Thirty-two items were presented either as written words or as pictures. After the presentation phase, participants had to recognize the target words and pictures among distractors, and then remember their mode of presentation. Results: All groups of participants recognized the pictures better than the words, except the patients with visual hallucinations, who presented the opposite pattern. The participants with visual hallucinations made more misattributions to pictures than did the others, and higher ratings of visual hallucinations were correlated with increased tendency to remember words as pictures. No association with auditory hallucinations was revealed. Conclusions: Our data suggest that visual hallucinations are associated with confusion between visual mental images and perception. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evaluation of a new radiographic technique: diagnostic accuracy for mandibular third molars

The study of individual symptoms of schizophrenia, such as auditory hallucinations, can contribute to effective treatment strategies. We review existing instruments for the assessment of characteristics and dimensions of auditory hallucinations in schizophrenia and other psychiatric disorders and describe their psychometric properties and implications for their use in clinical research and practice. In addition, three widely used global measurement scales for symptoms of schizophrenia, each of which contain questions that pertain to hallucinations, are included.     

Imagery vividness, reality testing, and schizophrenic hallucinations.

Tested groups of schizophrenics (n = 40) with and without auditory hallucinations and nonpsychotic controls (n = 20) on vividness of auditory imagery. Ss then participated in a listening task and were measured on their ability to assess the accuracy of their auditory perceptions. In accordance with the hypothesis, the hallucinators tended to have high, and the nonhallucinators low vividness of auditory imagery. Furthermore, the 3 groups differed significantly in their ability to assess the accuracy of their auditory perceptions, with the hallucinators demonstrating the greatest inability while the controls were best able to judge the correctness of their auditory perceptions. A model of hallucination formation is proposed in which vividness of auditory imagery and defective reality testing are seen as prerequisite but not necessarily sufficient to produce hallucinations. (19 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Auditory hallucinations inhibit exogenous activation of auditory association cortex

Percepts unaccompanied by a veridical stimulus, such as hallucinations, provide an opportunity for mapping the neural correlates of conscious perception. Functional magnetic resonance imaging (fMRI) can reveal localized changes in blood oxygenation in response to actual as well as imagined sensory stimulation. The safe repeatability of fMRI enabled us to study a patient with schizophrenia while he was experiencing auditory hallucinations and when hallucination-free (with supporting data from a second case). Cortical activation was measured in response to periodic exogenous auditory and visual stimulations using time series regression analysis. Functional brain images were obtained in each hallucination condition both while the patient was on and off antipsychotic drugs. The response of the temporal cortex to exogenous auditory stimulation (speech) was markedly reduced when the patient was experiencing hallucinating voices addressing him, regardless of medication. Visual cortical activation (to flashing lights) remained normal over four scans. From the results of this study and previous work on visual hallucinations we conclude that hallucinations coincide with maximal activation of the sensory and association cortex, specific to the modality of the experience.     

Auditory hallucinations in nonpsychotic children with affective syndromes and migraines: report of 13 cases

This report describes the discovery of a possible association between auditory hallucinations, migraine, and affective/anxiety disorders in nonpsychotic children. The cases were culled by a review of all consultations in an outpatient practice in an 8-month period. Thirteen cases of nonpsychotic children who experienced hallucinations (auditory in 12) were found. All but one suffered from a variety of major affective or anxiety/panic disorders and migraine headaches. The family histories were strongly positive for affective/anxiety disorders and migraine, and four of the parents also had a history of hearing voices. The age of onset of the auditory hallucinations, where known (8 cases), was between 4 and 8 years. In only two cases did the voices accompany the migraine attacks, and these two children also heard voices at other times. Although a strong association between migraine and anxiety, panic, and affective syndromes in adults has been repeatedly found in epidemiologic study, no such association has been studied in children, and this is the first known report of a possible association between migraine, affective/anxiety disorders, and auditory hallucinations in nonpsychotic children. It suggests the need for epidemiologic study.     

Cognitive factors in source monitoring and auditory hallucinations

BACKGROUND: In order to elucidate further the cognitive processes underlying auditory hallucinations, an experiment investigating delayed and immediate source monitoring for positive, negative and neutral verbal material was conducted with schizophrenic patients. METHODS: Patients experiencing auditory hallucinations, patients not experiencing auditory hallucinations and normal subjects participated in a word association task, rating their responses for how much a self-generated thought was their own, how controllable and involuntary it was and their confidence in these ratings. A delayed source monitoring test in which subjects had to recall the source (self or experimenter) of the words from the association task was also administered. RESULTS: Hallucinators showed a greater bias towards external attribution of their thoughts compared with both control groups for immediate attributions of source, but not for delayed attributions. Hallucinators showed a bias towards external attribution of emotional material for immediate source monitoring and all subjects showed a bias towards misattribution of positive material to an external source and negative material to an internal source for the delayed source monitoring task. CONCLUSIONS: These findings appear to be most consistent with theories proposing that hallucinations result from an external attributional bias for internal events. The implications of these results for research and practice are also discussed.     

Platelet monoamine oxidase activity in subgroups of schizophrenic disorders

This article summarizes findings from a series of studies that examined platelet monoamine oxidase (MAO) activity in patients with nonaffective schizophrenic disorders and schizophrenia-related depressions. The findings indicate that mean platelet MAO activity was not different from control values in the subgroup of nonaffective schizophrenic disorders without auditory hallucinations (that is, the S-1 subgroup). However, mean platelet MAO activity was reduced in the subgroup of nonaffective schizophrenic disorders characterized by the presence of auditory hallucinations often occurring in conjunction with paranoid features (that is, the S-2 subgroup). Moreover, we found that mean platelet MAO activity was increased in schizophrenia-related depressions characterized by histories of chronic asocial, eccentric, or bizarre behavior.     

The auditory hallucination: a phenomenological survey

A comprehensive semi-structured questionnaire was administered to 100 psychotic patients who had experienced auditory hallucinations. The aim was to extend the phenomenology of the hallucination into areas of both form and content and also to guide future theoretical development. All subjects heard 'voices' talking to or about them. The location of the voice, its characteristics and the nature of address were described. Precipitants and alleviating factors plus the effect of the hallucinations on the sufferer were identified. Other hallucinatory experiences, thought insertion and insight were examined for their inter-relationships. A pattern emerged of increasing complexity of the auditory-verbal hallucination over time by a process of accretion, with the addition of more voices and extended dialogues, and more intimacy between subject and voice. Such evolution seemed to relate to the lessening of distress and improved coping. These findings should inform both neurological and cognitive accounts of the pathogenesis of auditory hallucinations in psychotic disorders.     

Where the imaginal appears real: a positron emission tomography study of auditory hallucinations

An auditory hallucination shares with imaginal hearing the property of being self-generated and with real hearing the experience of the stimulus being an external one. To investigate where in the brain an auditory event is "tagged" as originating from the external world, we used positron emission tomography to identify neural sites activated by both real hearing and hallucinations but not by imaginal hearing. Regional cerebral blood flow was measured during hearing, imagining, and hallucinating in eight healthy, highly hypnotizable male subjects prescreened for their ability to hallucinate under hypnosis (hallucinators). Control subjects were six highly hypnotizable male volunteers who lacked the ability to hallucinate under hypnosis (nonhallucinators). A region in the right anterior cingulate (Brodmann area 32) was activated in the group of hallucinators when they heard an auditory stimulus and when they hallucinated hearing it but not when they merely imagined hearing it. The same experimental conditions did not yield this activation in the group of nonhallucinators. Inappropriate activation of the right anterior cingulate may lead self-generated thoughts to be experienced as external, producing spontaneous auditory hallucinations.     

Acoustic hallucinations as a symptom of a REM sleep-associated parasomnia

This 52-year-old man suffered from auditory hallucinations that occurred during brief episodes of sleep paralysis at the end of REM sleep periods. During these episodes the patient experienced a dissociated state of consciousness with REM sleep intrusions into wakefulness. The occurrence of this mixed state, and of excessive sleep-onset REM periods during daytime polysomnography (MSLT = Multiple Sleep Latency Test), point to a disorder of REM sleep generation. The existence of narcolepsy could be ruled out. The observation of REM sleep-associated hallucinations has been reported earlier. In the presented polysomnographic sleep studies the existence of a REM sleep associated parasomnia characterised by hallucinations and sleep paralysis could be confirmed.     

Behavioral management of chronic hallucinations and delusions following right middle cerebral artery stroke.

Describes the application of a brief psychotherapeutic intervention with potential utility in the management of hallucinations and delusions following brain damage. The procedure is illustrated with a case study of a 52-yr-old man who developed auditory hallucinations with delusional interpretation after a stroke that damaged the right temporo-parietal region. The intervention was developed based on substantial evidence of the efficacy of cognitive behavioral treatment of medication-resistant hallucinations in schizophrenic patients. Treatment involved cognitive restructuring via education of the patient and family members about the nature of the symptomatology and training in a number of simple behavioral compensatory strategies designed to minimize the impact of the symptoms on daily activities. Follow-up evaluations over a 20-month interval indicated that the intervention may be an efficacious supplement to pharmacological treatment of hallucinations and delusions following stroke. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Patient protection legislation: an oxymoron?

Hearing voices is distressing and frightening, but cognitive psychology can provide a range of interventions that enable people to live with their auditory hallucinations. Liam Clarke looks at ways to empower this patient group.     

Heterogeneity of auditory verbal working memory in schizophrenia.

The heterogeneity of schizophrenia remains an obstacle for understanding its pathophysiology. Studies using a tone discrimination screening test to classify patients have found evidence for 2 subgroups having either a specific deficit in verbal working memory (WM) or deficits in both verbal and nonverbal memory. This study aimed to (a) replicate in larger samples differences between these subgroups in auditory verbal WM; (b) evaluate their performance on tests of explicit memory and sustained attention; (c) determine the relation of verbal WM deficits to auditory hallucinations and other symptoms; and (d) examine medication effects. The verbal WM and tone discrimination performance did not differ between medicated (n = 45) and unmedicated (n = 38) patients. Patients with schizophrenia who passed the tone screening test (discriminators; n = 60) were compared with those who did not (nondiscriminators; n = 23) and healthy controls (n = 47). The discriminator subgroup showed poorer verbal WM than did controls and a deficit in verbal but not visual memory on the Wechsler Memory Scale–Revised (Wechsler, 1987), whereas the nondiscriminator subgroup showed overall poorer performance on both verbal and nonverbal tests and a marked deficit in sustained attention. Verbal WM deficits in discriminators were correlated with auditory hallucinations but not with negative symptoms. The results are consistent with a verbal memory deficit in a subgroup of schizophrenia having intact auditory perception, which may stem from dysfunction of language-related cortical regions, and a more generalized cognitive deficit in a subgroup having auditory perceptual and attentional dysfunction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Early dopaminergic drug-induced hallucinations in parkinsonian patients

OBJECTIVE: To characterize patients who develop hallucinations early in the course of dopaminergic therapy for Parkinson's disease (PD) and contrast them with patients developing hallucinations after chronic drug treatment. METHODS: Parkinsonian patients who met diagnostic criteria for PD, experienced hallucinations, had a detailed hallucination interview at the onset time of their first hallucination, and had a 5-year clinical follow-up or an autopsy in those 5 years were identified and divided into two groups for comparison: 12 patients who developed early hallucinations within 3 months of starting levodopa therapy and 58 PD patients who developed hallucinations after 1 year of dopaminergic therapy. We contrasted the quality, content, diurnal nature, and emotional elements of the hallucinations, as well as the 5-year follow-up data on diagnosis, disease course, community home or nursing home outcome, and mortality. RESULTS: Both groups experienced a predominance of visual hallucinations, visions of people and animals, and vivid colors and definition. Features distinctive to the early onset hallucinating patients included visions that persisted in daytime as well as nighttime, frightening content with paranoia, and accompanying nonvisual hallucinations, either auditory, olfactory, tactile, or combinations thereof. At the 5-year follow-up, none of the early onset hallucinators had PD as their sole disorder. Four of the 12 had an underlying psychiatric illness that included hallucinations or psychosis preceding their parkinsonism by several years. In the other eight patients at the 5-year follow-up, their parkinsonism evolved to include additional signs that were no longer consistent with PD. The primary diagnoses were diffuse Lewy body disease and Alzheimer's disease (AD) with extrapyramidal signs. Patients with early drug-induced hallucinations had significantly greater placement to nursing homes and greater mortality. CONCLUSIONS: Early onset drug-related hallucinations are not typical of PD. Their presence should signal an investigation of two alternative diagnoses, either a comorbid psychotic illness (often unrevealed by the patient initially) or an evolving parkinsonism-plus syndrome.     

Dichotic listening in college students who report auditory hallucinations.

College students were placed in 2 groups, hallucinators and nonhallucinators, on the basis of their responses to a verbal hallucinations questionnaire. Both groups were given a consonant-vowel version of a Dichotic Listening Test under 3 conditions: nonforced, forced-right, and forced-left. When hallucinators were instructed to attend to the left ear stimuli (forced-left condition), they had fewer correct responses to right ear syllables than did nonhallucinators. This resulted in a left ear advantage for hallucinators. When nonhallucinators were instructed to attend to the left ear, they maintained a right ear advantage. Results suggest that auditory hallucinations in college students are associated with differences in hemispheric functioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of postinatal stress on visual and auditory evoked potentials

Maturation of visual and auditory evoked potentials (mainly the P3 wave) of 10 controls and of 10 infants exposed to recurrent postnatal stressful events (crying spells lacking organic basis) have been compared. The sourse of maturation of P3 waves may serve as indicator of growth and nature of cognitive processes (including perception). Recurrent srying spells seemed to delay appearance of visual P3 wave, prolonged its latency, and delayed appearance of visible differences in the shape of visual P3 wave upon exposure of the subjects to different visual experiences. A compensatory increase of maturation of the auditory P3 wave appeared. The results suggest that recurrent exposure to stressful events during the early postnatal period may delay the ability of the memory banks of auditory engrams with unusual contents (including memory traces of stresses), a potential basis for future auditory hallucinations.     

Hallucinatory experience: a personal account

Presents a self-report by a nonpsychotic experimental psychologist of visual, auditory, and kinesthetic hallucinations that occurred during a 3-day period before spinal disc surgery. Probable factors related to the production of the phenomena are described, and the relation between hallucination and diagnosis is briefly discussed. (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)