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.     

Hallucinations, Negative Symptoms, and Response Bias in a Verbal Recognition Task in Schizophrenia.

Several studies have reported an association between hallucinations and tendency to make false alarms in acoustic signal detection tasks. Previous work on patients with schizophrenia has suggested that false recognitions and other types of memory error were positively associated with hallucinations and inversely associated with certain negative symptoms of withdrawal. In this study, 40 patients with schizophrenia were administered a word recognition task. Mixed lists of high- and low-frequency words were presented, then the target words had to be recognized among distractors in immediate and delayed recognition conditions. Hallucination scores were correlated with an increased bias toward false recognitions of nonpresented words. Affective flattening tended to be correlated with a reduced bias toward false recognitions. Anhedonia was significantly correlated with a reduced response bias. Hallucinations and anhedonia therefore presented an opposite association with the response bias. The influence of word frequency and delay on this association is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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.     

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In neuropsychological vulnerability research the visual backward masking task, the Span of Apprehension, the degraded stimulus Continuous Performance Test (dsCPT), and the Wisconsin Card Sorting Test have been described as putative indicators for the predisposition to develop negative (schizophrenic) symptoms. The present study assesses the stability of the association between neuropsychological tests and negative symptoms by examining clinically improved patients. The interdependence between the four cognitive measures and clinical symptomatology was examined in 31 patients with DSM III-R and ICD-10 schizophrenia suffering predominantly from negative symptoms. Backward masking performance was related to affective flattening and anxiety-depression. False alarm rate on dsCPT was associated positively with affective flattening and hallucinations, and negatively with avolition. Card sorting preseverative errors correlated negatively with anhedonia, non-preservative errors correlated positively with avolition. Correlations notwithstanding, the data provide evidence in support of the relative independence of neuropsychological functions and negative symptoms in clinically improved schizophrenics.     

Olfactory identification deficits in Down's syndrome and idiopathic mental retardation

We investigated olfactory identification in children and adults with Down's syndrome (DS) and idiopathic mental retardation (IMR) and in age-matched normal controls (NC). Identification was assessed with a four alternative-forced-choice task modified from the University of Pennsylvania Smell Identification Test (M-UPSIT) and a yes/no task yielding measures of discrimination and response bias for the same stimulus material. Control tactile identification tasks were also administered. Results were that odor identification performance on both tasks was specifically impaired in DS compared to IMR and NC. Accuracy of identification on the M-UPSIT correlated inversely with age in DS only. When uncertain, DS and IMR subjects guessed "yes" more often than "no" on the Yes/No task (liberal decision bias) and guessed the last response alternative on the M-UPSIT (recent position bias), whereas the normal subjects had neutral decision bias on the Yes/No task and matched the objective position presentation probabilities on the M-UPSIT. Decision bias correlated with accuracy of identification in both tasks for the DS subjects only.     

Slow-wave sleep and symptomatology in schizophrenia and related psychotic disorders

Deficits in slow-wave sleep (SWS), or delta sleep, are frequently seen in schizophrenia, but their relationship with schizophrenic symptomatology remains unclear. We examined the association between visually scored and automated measures of SWS and positive and negative symptoms in a series of unmedicated patients with schizophrenia and related psychotic disorders. Total and average automated delta wave counts were significantly inversely associated with negative symptoms overall, and the psychomotor poverty syndrome in particular. Total delta counts were also inversely related to the disorganization syndrome. No relation was seen between reality distortion or the Brief Psychiatric Rating Scale (BPRS) positive symptoms and SWS. These findings support the view that SWS deficits may be related to negative symptoms of schizophrenia and may perhaps be mediated by impaired functioning of frontothalamic neural circuits.     

Immunoglobulin levels in psychiatric patients

In a study of 19 schizophrenic patients, 7 nonschizophrenic patients, and 31 controls, the authors found significantly higher mean serum levels of 1) immunoglobulin A in schizophrenic women then in control women and in schizophrenic blacks than in either schizophrenic whites or black controls. 2) immunoglobulin D in schizophrenic blacks than in schizophrenic whites, 3) immunoglobulin M in controls than in nonschizophrenic patients, and 4) immunoglobulin G (IgG) in schizophrenics whose urine was positive for phenothiazines than in schizophrenics whose urine was negative for phenothiazines. High serum levels of IgG were associated with no or mild hallucinations and low levels with moderate or severe hallucinations. Black female patients had significantly more severe hallucinaions than white female patients. The authors discuss the possible implications of these findings.     

Serotonergic function and negative and depressive symptomatology in schizophrenia and major depression

BACKGROUND: Serotonergic abnormalities are found in both major depressive disorder (MDD) and schizophrenia. Depressive symptoms commonly occur alongside the negative or defect symptoms in schizophrenia and antiserotonergic drugs may be particularly effective in their treatment. We wished to explore whether these symptoms could be distinguished biologically by directly comparing serotonergic function in these two illnesses. METHOD: Fifteen patients with MDD and 13 patients with schizophrenia underwent testing with the specific serotonin releasing agent D-fenfluramine (D-FEN). Prolactin and cortisol responses were measured to ascertain central serotonergic function. Individual patient results were compared with their own carefully matched control to correct for the effect of age, sex, weight and menstrual cycle, before the two patient groups were then compared. RESULTS: Prolactin responses differed significantly between the two patient groups, being lower in MDD patients and higher in schizophrenia patients than their individually matched controls. Cortisol responses did not differ. Within the schizophrenia group, increased serotonergic function correlated positively with depressive symptoms, but there was no such correlation with defect symptoms. Depressive scores were negatively correlated with the presence of negative symptoms in the schizophrenic group. CONCLUSIONS: Schizophrenia and MDD have distinct and opposite neuroendocrine responses to D-FEN. There is no evidence that depressive symptoms in these two conditions have a common serotonergic basis. Moreover, these responses distinguished between negative and depressive symptoms in our schizophrenic group.     

Schizophrenic symptomatology: Reaction or strategy? A study of contextual antecedents.

Several explanations have been offered in recent research for schizophrenic symptomatology within an interpersonal situation. The purpose of the present study was to separate 2 possible antecedent conditions, contextual emotionality and demand for self-disclosure, to clarify the immediate antecedents of symptomatic expression. A total of 40 schizophrenic and 40 nonschizophrenic (alcohol- and drug-abusing) inpatients were selected for study, and demand for self-disclosure and emotionality were independently manipulated. Each patient was assigned to 1 of 8 possible conditions. These conditions involved 2 levels each of interviewer emotionality, task demand, and diagnosis. Data show that under nonreciprocal conditions, irrespective of specific emotion level or task demand, nonparanoid schizophrenics were more autistic than were paranoid schizophrenics or alcoholics. High emotion and self-disclosure demand under salient reciprocal conditions elicited more autism among paranoid schizophrenics than among any of the other groups on this condition. Although the results do not allow a choice between the intimacy avoidance and emotional intolerance hypotheses, both factors interacted in a complex fashion for each subgroup. Results are discussed in terms of subjective personal risk and differential motivational dynamics of the groups. In addition, implications for therapeutic intervention in terms of interview reciprocity are discussed. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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)     

Intentional inhibition in memory and hallucinations: Directed forgetting and updating.

Hallucinations have been recently associated with inhibitory deficits in memory. In this study, the authors investigated whether hallucinations were related to difficulties to inhibit irrelevant information from episodic memory (Experiment 1) and working memory (Experiment 2). In Experiment 1, a directed forgetting task was used. This task measures participants' ability to intentionally forget some recently learned material, when instructions indicate that it is no longer relevant. In Experiment 2, an updating task was used. This task requires participants to intentionally suppress irrelevant information from working memory. Results showed that patients with schizophrenia with hallucinations presented inhibitory deficits in the directed forgetting task and an increase in the number of intrusions in the updating task, compared to patients without hallucinations and healthy controls. No correlations were found between indices of inhibition and other general, negative or positive symptoms. These findings support the existence of an association between intentional inhibition in memory and hallucinations, and they suggest that problems to suppress memory representations can underlie hallucinations in schizophrenia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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OBJECTIVE: The authors examined the effect of prolonged clozapine treatment on central serotonergic (5-HT) function in schizophrenia. METHOD: Prolactin responses to the 5-HT releasing agent d-fenfluramine were measured in two groups of 10 schizophrenic subjects. The first group was tested twice, before and after a mean of 10 weeks of clozapine treatment. The second group was tested after a mean of 20 months of clozapine treatment. RESULTS: The prolactin response was significantly blunted in these 20 patients treated with clozapine. There was a significant positive correlation between d-fenfluramine-evoked prolactin release and the overall positive symptom score and the hallucination and delusion subscores of the Scale for the Assessment of Positive Symptoms. CONCLUSIONS: Blunted 5-HT-mediated prolactin responses in schizophrenic patients receiving clozapine monotherapy for up to 20 months were correlated with reductions in positive symptoms. This suggests that 5-HT antagonism is relevant to clozapine's efficacy in alleviating hallucinations and other positive schizophrenic symptoms.     

Concurrent and predictive electrodermal correlates of symptomatology in recent-onset schizophrenic patients.

Electrodermal activity and symptomatology were interrelated in a group of 56 male and 13 female recent-onset schizophrenic patients. Electrodermal activity was indexed by the frequency of nonspecific skin conductance responses and the number of trials to habituation of the skin conductance orienting response. Symptomatology was assessed by the Brief Psychiatric Rating Scale (BPRS) on 2 separate test occasions. The 1st test occasion was during the inpatient period when psychotic symptoms were prevalent and medications were variable. The 2nd test occasion was several mo later during an outpatient period when symptoms were stabilized and medications held constant. Electrodermal activity was positively and significantly related to a number of symptoms in male patients, most reliably the BPRS factors Activation and Hostility/Suspiciousness. These relationships were most consistent during the outpatient period. Of particular theoretical interest, greater electrodermal activity during the inpatient period was associated with greater outpatient psychopathology. The results suggest that heightened inpatient electrodermal activity is predictive of poor short-term symptomatic recovery in recent-onset, acute, male schizophrenic patients. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Anti-hallucinatory coping strategies in schizophrenia

Despite the effectiveness of antipsychotic drugs in schizophrenia, many patients continue to have persistent positive symptoms like hallucinations. It has provided new interest for coping strategies used by hallucinated patients. Therefore the aim of the study was to explore the existence of such strategies in 50 schizophrenic patients defined by the presence of hallucinations. A specific questionnaire about coping strategies and a scale for the assessment of positive and negative symptoms were used. Our results showed that each patient developed at least one strategy, even rudimentary. Moreover, whenever the type of hallucinations, they developed specific coping strategies, most of the time logically used: they used them as much as they were efficace. So coping strategies should be taken into account for the clinical management of hallucinated patients. Learning of these strategies through behavioural and cognitive therapy could help patients suffering from resistant hallucinations.     

Forward and backward visual masking of contour by light in positive- and negative-symptom schizophrenia.

Forward and backward masking of contour by light was investigated with stimulus onset asynchronies from 20 to 180 ms in a group of 22 schizophrenic patients and 22 matched normal controls. Individuals with schizophrenia were selected using American Psychiatric Association (1987) criteria and were also assessed using the Andreasen scales for the presence of positive and negative symptoms (N.C. Andreasen, 1981, 1983). The Andreasen scales were used to divide schizophrenic patients into 2 subgroups (positive and negative symptoms). Positive-symptom schizophrenic patients showed no differences in their target duration thresholds or in their backward masking functions. Negative symptom schizophrenic patients showed significantly longer target duration thresholds and experienced significantly more backward masking. There was no difference between schizophrenic patients and controls in forward masking. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Coping with certain symptoms of acute schizophrenic psychosis

Coping attempts with selected symptoms of acute schizophrenic psychosis (delusions, hallucinations, formal thought disorders) are described in 40 patients. Their correlations with basic socio-demographic and clinical variables are also analyzed.     

Assessing declarative memory in schizophrenia using Wisconsin Card Sorting Test stimuli: the Paired Associate Recognition Test

The Paired Associate Recognition Test (PART) was developed to measure declarative memory using Wisconsin Card Sorting Test (WCST) stimuli, so that both tasks could be administered during functional neuroimaging to differentiate memory and executive function, and associated frontal and temporal lobe activation in schizophrenia. The current study was designed to compare PART and WCST performance in schizophrenic patients and to examine effects of medication and symptomatology. The PART, WCST, and standard declarative memory tasks were administered to 30 chronic schizophrenic patients and 30 matched healthy control subjects. Supporting task validity was the finding that patients were equally impaired on the PART and the WCST. Neuroleptics did not appear to affect performance. The effect of anticholinergic medication correlated negatively with WCST performance in a small subsample. Severity of schizophrenia-specific symptoms measured at intake on the Brief Psychiatric Rating Scale correlated negatively with performance on the WCST. These results support the application of the PART and WCST in future functional neuroimaging studies.     

Self-esteem in schizophrenia: Relationships between self-evaluation, family attitudes, and symptomatology.

Participants with schizophrenia (N=59) were assessed on self-evaluation, symptomatology, and positive and negative affect (expressed emotion) from significant others. An interview-based measure of self-evaluation was used and two independent dimensions of self-esteem were derived: negative and positive evaluation of self. As predicted, negative self-evaluation was strongly associated with positive symptoms, a more critical attitude from family members was associated with greater negative self-evaluation, and analyses supported a model whereby the impact of criticism on patients' positive symptoms was mediated by its association with negative self-evaluation. The interview-based method of self-esteem assessment was found to be superior to the questionnaire because its predictive effects remained after depressed mood was accounted for. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Expressed emotion, attributions, and schizophrenia symptom dimensions.

Using a sample of 40 Anglo American family members of schizophrenic patients, the present study replicates and lends cross-cultural support for an attribution–affect model of expressed emotion (EE). Consistent with attribution theory, the authors found that highly critical relatives (high-EE) viewed the illness and associated symptoms as residing more within the patient's personal control as compared with less critical relatives (low-EE). A content analysis classified the types of behaviors and symptoms most frequently criticized by relatives. Symptoms reflecting behavioral deficits (e.g., poor hygiene) were found to be criticized more often than symptoms reflecting behavioral excesses (e.g., hallucinations). In line with an attribution–affect framework, relatives may be less tolerant of behavioral deficits because they are viewed as intentional, whereas behavioral excesses are easily recognized as core symptoms of mental illness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)