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PubMed2004

Thinking and hallucinating: reciprocal changes in sleep.

Internal deliberations (focused thoughts) and endogenous percepts (hallucinations) vary in a reciprocal manner across the states of waking and sleep, paralleling changes in regional brain activation. As subjects go from waking through sleep onset to NREM sleep and then to REM sleep, they report progressively more hallucinoid imagery and progressively less thinking. We have investigated whether this reciprocity in cognition between NREM and REM is maintained throughout the night. To do so, we analyzed 229 REM and 165 NREM reports collected with the Nightcap sleep monitoring system from 16 participants in their homes over 14 nights. The reports were scored for the presence of hallucinations and directed thinking by external judges. As predicted, hallucinations were more frequent in REM than in NREM for each segment of the night, and directed thinking was more frequent in NREM in the first 5 h of the night. Late in the night, directed thinking was equally infrequent in NREM and REM. At the same time, hallucinations increased within both NREM and REM as the night progressed, whereas directed thinking decreased in NREM and remained at a stable, low level in REM. These findings suggest that a reciprocal shift in focused thinking and hallucinating is a general property of cognitive activity across the wake-sleep cycle. Biological evidence supports the hypothesis that these cognitive changes are governed by specific state regulatory and neurocognitive processes at several levels of the brain.

Adult↗
PubMed1983

Hallucinations in Kenyan schizophrenic patients.

Eighty Kenyan 'psychotic' patients were screened using the New Haven Schizophrenic Index (NHSI) and were all studied for hallucinations using standardised definitions. Fifty-one of the patients were NHSI positive and the rest NHSI negative. Sixty-one percent of the NHSI positive had hallucinations in one or more modalities as compared with 31% of the NHSI negative group. Of the NHSI positive 51% had auditory hallucinations directly to the patient, 43% had visual hallucinations and 25% had olfactory hallucinations. These results are compared and contrasted with the very few similar observations made elsewhere.

Adolescent↗
PubMed1986

Lateralization phenomenon of complex auditory hallucinations.

A case is described of a patient who developed a transient verbal hallucination, lateralized to the right ear, and fluent aphasia after a hemorrhagic infarction in the left superior temporal gyrus. On the basis of this patient and the cases in the literature showing unilateral complex auditory hallucinations, the clinical significance of the lateralization phenomenon of complex auditory hallucinations was investigated. As a result, the lateralization phenomenon of complex auditory hallucinations could be considered a significant clinical sign indicating the existence of a lesion in the superior temporal gyrus opposite the hallucination side.

Aphasia↗
PubMed1998

A comparison of the long-term effectiveness of distraction and focusing in the treatment of auditory hallucinations.

Cognitive-behavioural interventions for patients experiencing neuroleptic resistant auditory hallucinations have fallen into two main categories: those which encourage distraction as a coping strategy, and those which encourage patients to focus on or expose themselves to their hallucinations. A 20-session distraction treatment was compared with an equal length focusing treatment for 19 patients who were experiencing chronic auditory hallucinations. Patients were followed-up for approximately 2 years. No differences were observed between the groups for outcome on symptom severity overall, although the focusers showed a greater belief that their voices were their own thoughts at the final follow-up point. When the two groups were combined, there was a significant reduction in the frequency of hallucinations and the disruption to life caused by them during treatment, although this was not maintained at follow-up. During treatment, there was a significant increase in self-esteem for focusers but a significant decrease for distracters. At 2-year follow-up, both focusers and distracters showed a reduction in self-esteem in comparison to the end of therapy. The results show no overwhelming advantage of one treatment over the other and confirm previous observations of the difficulty of treating hallucinations with cognitive-behaviour therapy (CBT). However, there was some indication that CBT influenced some important clinical variables and further investigation is warranted.

Adaptation, Psychological↗
PubMed2002

The neural basis of Charles Bonnet hallucinations: a hypothesis.

OBJECTIVES: To describe the hallucinations occurring as a result of a macular hole in each eye and to investigate the neural basis. METHODS: Psychophysical observations including sketches of the hallucinations calibrated for size. RESULTS: All the hallucinations were of the geometric (patterned) type and lasted for only a few days. CONCLUSIONS: The observations can be explained on the basis of a "deafferentation" model, which is described in some detail. It is proposed that the hallucinations result from activation of the "blobs" of area V1 and the "stripes" of area V2 in the visual cortex. A theory is proposed to account for the disappearance of the hallucinations by a "filling in" mechanism.

Animals↗
PubMedDate not supplied

Command hallucinations: who obeys and who resists when?

The impact of auditory command hallucinations on the behaviour of schizophrenic patients sometimes appears to be unpredictable. In order to tackle this problem, the psychopathological characteristics of command hallucinations in 31 schizophrenic patients were assessed using a 24-item questionnaire. Using binary data and relative risk analysis methods, predictors were determined for obeying or resisting command hallucinations. Characteristics of voices and the attitude toward the voices appear equally important for prediction. A set of three psychopathological characteristics comprising a voice known to the patient, emotional involvement during the hallucinations, and seeing the voice as real provides significant predictivity of behaviour following command hallucinations. These results are interesting for clinical and forensic psychiatrists.

Adolescent↗
PubMedDate not supplied

Seeing visual hallucinations with functional magnetic resonance imaging.

We have used blood oxygenation level dependent imaging with functional magnetic resonance imaging (fMRI) to investigate the visual cortex response to photic stimulation during and in the absence of continuous visual hallucinations. A patient with cortical Lewy body dementia who experienced persistent and vivid complex hallucinations underwent fMRI on and off treatment with risperidone. When he was not hallucinating, photic stimulation produced a normal bilateral activation in striate cortex. During hallucinations, very limited activation in striate cortex could be induced. We interpret this result as indicating that at least part of the activity in the brain responsible for the experience of visual hallucinations is located in the primary visual cortex.

Hallucinations↗
PubMed1987

The clinical significance of command hallucinations.

Patients with command hallucinations (voices ordering particular acts, often violent or destructive ones) are commonly assumed to be at high risk for dangerous behavior. The authors reviewed 789 consecutive inpatient admissions. Of 151 patients with auditory hallucinations, 58 (38.4%) heard commands. The presence of auditory hallucinations was significantly associated with diagnosis, demographic variables, and use of maximal observation and seclusion. However, patients with command hallucinations were not significantly different from patients without commands on demographic and behavioral variables, including suicidal ideation or behavior and assaultiveness. These findings suggest that command hallucinations alone may not imply greater risk for acute, life-threatening behavior.

Adult↗
PubMed1999

Selective speech perception alterations in schizophrenic patients reporting hallucinated "voices".

OBJECTIVE: The authors tested a model of hallucinated "voices" based on a neural network computer simulation of disordered speech perception. METHOD: Twenty-four patients with schizophrenia spectrum disorders who reported hallucinated voices were compared with 21 patients with schizophrenia spectrum disorders who did not report voices and 26 normal subjects. Narrative speech perception was assessed through use of a masked speech tracking task with three levels of superimposed phonetic noise. A sentence repetition task was used to assess grammar-dependent verbal working memory, and an auditory continuous performance task was used to assess nonlanguage attention. RESULTS: Masked speech tracking task and sentence repetition performance by hallucinating patients was impaired relative to both nonhallucinating patients and normal subjects. Although both hallucinating and nonhallucinating patients demonstrated auditory attention impairments when compared to normal subjects, the two patient groups did not differ with respect to these variables. CONCLUSIONS: Results support the hypothesis that hallucinated voices in schizophrenia arise from disrupted speech perception and verbal working memory systems rather than from nonlanguage cognitive or attentional deficits.

Adult↗
PubMed2005

Duration of untreated psychosis and time to treatment response for delusions and hallucinations.

OBJECTIVE: Duration of untreated psychosis is associated with time to treatment response among patients with schizophrenia. However, individual psychotic symptoms have not been investigated in this context. The authors examined the relationship between duration of untreated psychosis and time to response for hallucinations and delusions. METHOD: Data were available for 118 patients with first-episode schizophrenia in a longitudinal treatment study. Patients received open-label treatment with conventional antipsychotics and were followed for up to 5 years. Duration of untreated psychosis was correlated with time to response for delusions and hallucinations, and predictors of time to response were examined. RESULTS: Time to response for delusions was significantly longer than that for hallucinations. Duration of untreated psychosis was significantly correlated with time to response for delusions but not for hallucinations. In regression analyses, duration of untreated psychosis was the only predictor for time to response for delusions; it was not a predictor for hallucinations. CONCLUSIONS: The results suggest that duration of untreated psychosis may be specifically associated with time to response for delusions. This association may have clinical implications.

Adult↗
PubMed2000

The relationship between command hallucinations and violence.

OBJECTIVE: The purpose of this study was to describe the relationship between command hallucinations and violent behavior. METHODS: One hundred and three psychiatric inpatients completed measures of command hallucinations, other psychotic symptoms, violent behavior, and social desirability response biases. RESULTS: Thirty percent of the patients reported having had command hallucinations to harm others during the last year, and 22 percent of the patients reported they complied with such commands. Logistic regression analyses suggested that patients who experienced command hallucinations to harm others were more than twice as likely to be violent, even when the analysis controlled for demographic variables, history of substance abuse, and social desirability response biases. CONCLUSIONS: The results support the clinical utility of asking about command hallucinations when assessing the risk of violence in patients with major mental disorders.

Adolescent↗
PubMed1991

Hallucinations and associated factors in Alzheimer's disease.

In a consecutive sample of 230 community-dwelling patients with probable Alzheimer's disease, a structured interview yielded evidence of current hallucinations in 29.1% and misperceptions in another 11.3%. Visual and auditory modalities were similarly represented in apparent hallucinations. Hallucinations prior to the current monitoring period were rare among patients with misperceptions or with no perceptual abnormality. The probability of hallucinations was associated with the severity of cognitive dysfunction, the degree of other behavioral disturbances, and the presence of extrapyramidal signs. A logistic regression model predicting hallucinations based on these diverse clinical features accurately classified 87.0% of the sample.

Activities of Daily Living↗
PubMed2002

Effect of culture and environment on the phenomenology of delusions and hallucinations.

BACKGROUND: The present study was conducted to compare the influence of culture and immediate environment on the phenomenology of schizophrenic symptoms by examining the actual content of delusions and hallucinations in three groups of schizophrenic patients. METHOD: Pakistanis living in Britain (BP; N = 53), Pakistanis in Pakistan (PP; N = 98) and British White (BW; N = 50). The content of the patients' delusions and hallucinations was obtained from medical records and key-workers' reports from All-Saints Hospital, Birmingham and two psychiatric units in Lahore. All references to delusions and hallucinations were coded in accordance with the classification scheme developed for the Present State Examination (Wing et al., 1974). RESULTS: Comparisons indicated greater differences in phenomenology of delusions and hallucinations between the Pakistani pair (BP vs. PP) than between the British groups (BP vs. BW). The findings suggested a stronger influence of the immediate environment on the pathogenesis of delusions and hallucinations. CONCLUSIONS: The results are discussed with reference to the cultural and religious values of the ethnic groups.

Adult↗
PubMed1997

A cross-cultural study of the attitudes of mental health professionals towards auditory hallucinations.

The usefulness of psychological interventions for auditory hallucinations is becoming increasingly accepted in Western cultures, but there are few data concerning the views of professionals working in non-Western societies. In this study, 195 psychologists and psychiatrists working in Saudi Arabia (SA) and Britain (UK) responded to a questionnaire regarding their (a) attitudes towards various clinical aspects of auditory hallucinations, (b) perceptions of the clinical value of psychological and pharmacological treatments and of the inputs of the two professions and (c) levels of social distance from people who experience auditory hallucinations. UK staff believed that there is a greater range of possible causes and diagnoses for auditory hallucinations than SA staff, who in turn had more confidence in the efficacy of psychological and pharmacological treatments. UK staff reported significantly less social distance from this group of patients. The results suggest that the use of psychological approaches to helping people with auditory hallucinations could be affected by cultural views of the causes and treatment.

Attitude of Health Personnel↗
PubMed1989

True hallucinations in non-psychotic states.

While hallucinations are known to occur as conversion symptoms in non-psychotic psychiatric states such as hysteria and grief, there is a lack of distinction between true and pseudo-hallucinations in such cases. We discuss the rationale which has necessitated this distinction, affirm that true hallucinations can occur in non-psychotic states, discuss the characteristics of such hallucinations, and postulate certain factors which may lead to hallucinations in non-psychotic states being judged as "true."

Adolescent↗
PubMed1983

Cognitive vulnerability to auditory hallucination. Preferred imagery mode and spatial location of sounds.

Goldstone and Sarbin proposed that auditory hallucinations occur because imagery in a non-preferred sensory mode is more easily misinterpreted as having an external origin. This led to the hypothesis that auditory hallucinators would show less preference for auditory than for visual imagery. Our results suggest that this is true. We also compared the vividness of internally-generated auditory imagery with that of visual imagery, independently of preference, to see whether vividness was impaired in the nonpreferred mode in hallucinators. The evidence suggested that this was not the case, but we did find a significantly deficient capacity for creating vivid images of either kind in process patients (i.e. those with poor premorbid status) compared with reactive (good premorbid) patients, regardless of any history of hallucinations. The withdrawal of external attention which characterizes process patients might also be expected to impair their ability to confirm or disconfirm the external origin of an auditory stimulus. We predicted therefore that process hallucinators would be particularly incompetent in spatial location of sounds: our experimental results confirmed this to be the case.

Adult↗
PubMed1984

Visual hallucinations and sensory delusions in the elderly.

One hundred and fifty successive referrals to a psychogeriatrician were assessed for visual hallucinations. Forty-four (29.33 per cent) patients reported visual perceptual disturbances. No differences between hallucinators and non-hallucinators were found in terms of sex, age, length of illness, underlying psychiatric diagnosis or cognitive score. There was a significant correlation between presence of hallucinations and eye pathology (less than .001) and delusions (less than .001). The phenomenological characteristics of the visual hallucinations are analyzed. The "picture" sign is described in 7 patients and the Charles Bonnet syndrome in two. The significance of these findings is discussed.

Aged↗
PubMed1984

Psychotic children with hallucinations.

In a retrospective study, 20 psychotic children and adolescents with hallucinations were compared with 15 psychotic controls without hallucinations. In the former, auditory hallucinations predominated, which tended to be localised in the internal space of the child. Subjects with hallucinations had significantly more symptoms of depression and anxiety, more precipitants of illness and problems in reading ability. There was a trend for increased laconic speech in them. The findings suggest a link between hallucinations and mood and cognitive changes in children and adolescents with psychoses of late onset.

Adolescent↗