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Biomedical subjects

D R Hemsley

Publications and source records attributed to D R Hemsley.

At least 55 records · Page 3Linked to original sources
PubMed1986

The formation of maintenance of delusions: a Bayesian analysis.

This paper argues that recent research on normal-belief formation is relevant to our understanding of the establishment and maintenance of delusions. Bayesian theory provides a normative model of the way in which evidence relevant to normal beliefs may be evaluated: this makes it possible to classify delusional beliefs in terms of deviations from optimal Bayesian inference. Some hypothetical forms of deviation appear to correspond closely to cognitive processes observed in some groups of deluded patients. Theories of the precise nature of the abnormal judgemental processes also have implications for psychological approaches to treatment of deluded patients. The role of hallucinations in the formation and/or maintenance of delusions and the extent to which the distortions of cognitive processes associated with delusions are content-specific or mood-specific are also considered.

Cognition Disorders↗
PubMed1985

Visual feedback of vocal intensity in the treatment of hysterical aphonia.

This case report describes the successful though temporary removal of a hysterical aphonic symptom in a 49-year-old male patient by using visual feedback of changes in vocal intensity. Following symptom removal the patient experienced considerable emotional distress due to a number of factors. His aphonia returned and has proven resistant to subsequent intervention. At a 1-year follow-up his condition was found to be unchanged. The case is discussed in relation to the common controversy over the wisdom of symptomatic treatment for hysterical reactions, and a practical means of resolving the disagreement is considered.

Aphonia↗
PubMed1984

Relationship between subjective self-report of cognitive dysfunction and objective information-processing performance in a group of hospitalized schizophrenic patients.

This study examines the relationships between subjective self-report of cognitive difficulties associated with schizophrenia and performance parameters of an objective choice reaction time task. The predicted relationships did not emerge and the results are discussed with regard to the methodological difficulties of measuring self-report and the features of the CRT task used. One positive finding was the significant relationship between chronicity of illness and the CRT measures.

Adolescent↗
PubMed1984

Illusory correlations in paranoid and non-paranoid schizophrenia.

Paranoid schizophrenics, non-paranoid schizophrenics and normals were assessed on tasks designed to demonstrate their tendency to perceive illusory correlations. It was hypothesized that paranoids would show stronger illusory correlations than normals due to the predominance of their schemata when processing information, and that non-paranoids would show weaker correlations than normals because of their impaired ability to establish conceptual categories. Results were broadly consistent with predictions.

Cognition↗
PubMed1984

Depression: a breakdown of perceptual defence?

The effect of depressed mood on the tachistoscopic recognition of neutral/unpleasant words was investigated in a group of 18 depressed inpatients and in 17 normal controls. A 50% recognition threshold for 30 neutral words was calculated for each subject, in order to exclude the effects of depressive slowness on the experimental task. Each subject was tachistoscopically presented with a series of experimental words (30 neutral/30 unpleasant) at his 50% level, and the ratio of neutral to unpleasant words recognised calculated. Depressed subjects tended to recognise a higher ratio of unpleasant to neutral words.

Adult↗
PubMed1983

Sensory experience as a trigger in Gilles de la Tourette's syndrome.

The case to be reported presented with multiple motor tics. During the course of therapy, directed along behavioural lines, a model of the nature of the movements emerged which was later found to be strikingly similar to that described by Bliss (1980). The patient (J) complained of a "horrible" sensation, similar to an "itch", which always preceded the tic movements and which could be removed by movement. Occasionally, by supreme effort, the "itch" would be resisted and movement avoided. These sensations could thus be viewed as a trigger for the movements. The implications of such an analysis for current conceptualisations of, and intervention with, motor tics are discussed.

Adult↗
PubMed1983

The use of directed masturbation training in the treatment of primary anorgasmia.

This review evaluates the evidence for the effectiveness of the use of directed masturbation training in the treatment of primary anorgasmia. Various methodological problems are discussed but it is clear that some clients can be helped by this form of therapy. As yet it is unclear which clients are likely to benefit from such a programme or what are the most important factors influencing outcome. Some social and cultural implications, including issues relating to the role of the therapist, are briefly discussed.

Adult↗
PubMed1983

Depression and the accessibility of memories. A longitudinal study.

A group of depressed patients and a group of normal subjects were assessed on two occasions. On each they were required to recall past real life experiences associated with a series of stimulus words. Subjects were subsequently required to rate each experience for happiness and pleasantness. The depressives showed an increased probability of recalling sad memories; within this group there was a significant relationship between severity of depressed mood and the percentage of sad memories recalled. The extent of reduction in depressed mood from occasion 1 to occasion 2 was significantly related to the increase in accessibility of happy memories and the decrease in recall of sad memories. For those patients who improved between the two occasions there was a significant reduction in the probability of recall of a very unhappy memory. The results extend the previous findings on the effect of mood state on the accessibility of memories of differing affective tone. The findings are discussed in terms of context specific encoding and retrieval.

Adult↗
PubMed1982

The effects of hyperventilation; individual variability and its relation to personality.

Self-reported affective and somatic disturbances and heart rate changes resulting from a brief period of voluntary hyperventilation are presented and related to individuals' Eysenck Personality Questionnaire (E.P.Q.) scores. Considerable individual variability was observed in the effects of hyperventilation. Neuroticism was significantly correlated with affective but not self-reported somatic or objectively measured heart rate changes. Other possible determinants of observed variability and its possible relevance to the etiology of panic attacks are discussed.

Adult↗
PubMed1982

The stability of personality measures in drug abusers during withdrawal.

The present report is of the stability of personality measures within a group of polydrug abusers during withdrawal. The EPQ (Eysenck and Eysenck, 1975) and a questionnaire assessing disturbances of perceptual and cognitive functioning (Reichenstein, 1976) were the instruments employed. Initial assessments were made within 24 hours of admission and were repeated at 4 weeks and 8 weeks after drug withdrawal. Scores on Psychoticism, Neuroticism, and Extraversion showed considerable stability, although the Lie Score decreased across occasions. Mean scores on the Reichenstein Scale were initially elevated but subsequently normalized. The findings suggest that previously reported scores of drug abusers on the EPQ are not an artifact of drug status.

Adolescent↗
PubMed1981

A psychophysical investigation of auditory functioning in schizophrenia.

The present report is of the application of Treisman's (1964) model of perceptual functioning to the study of schizophrenic hallucinations. It was hypothesized that hallucinators would perform on an auditory threshold task as if possessing a perceptual system showing high levels of spontaneous neural activity (In). Three groups were compared on the Weber functions for pure tone intensity: schizophrenic hallucinators, old people and anxiety neurotics. From these functions, estimates of In were calculated using Barlow's (1957b) method. No group differences were found. An alternative explanation of schizophrenic hallucinations, in terms of increased responsiveness to normal levels of background sensory activity, is proposed.

Adult↗
PubMed1981

The effects of varying auditory input on schizophrenic hallucinations.

The present report is of the effect of variations of auditory input on hallucinatory experiences in seven schizophrenic patients. Nine experimental conditions, each of two minutes' duration were compared with a control condition. At the end of each period subjects were required to rate the duration, loudness, and clarity of hallucinations during that time. Experimental conditions varied according to the amount of structure present in the material and in its attention-commanding properties. One condition required the active monitoring of material presented and resulted in the greatest decrease in hallucinatory experiences. For the passive conditions, findings were broadly consistent with predictions, indicating that it is not stimulation per se, but rather the extent to which structure is present and attended to, that is important in determining the occurrence of hallucinatory phenomena.

Acoustic Stimulation↗
PubMed1980

Genetic influences on measures of selective attention and speed: a twin study.

Measures of selective attention and speed which have been employed in the study of disturbances of cognitive functioning in schizophrenia were used in a study of 20 MZ and 20 DZ normal twin pairs. Results suggest the presence of a genetic contribution to scores on such tasks, particularly for the speed measures.

Attention↗
PubMed1980

Shadowing by context in schizophrenia.

Schizophrenics, depressives, and normal controls were tested on a binaural listening task in which pairs of simultaneous continuous prose passages were presented. Subjects were required to shadow one passage of each pair and ignore th other. The passages in each pair, although differing markedly in content, were inseparable on the basis of their physical features. As predicted, the performance of schizophrenics on such a task was markedly worse than that of the other groups. The results were interpreted within the framework of Broadbent's model of selective attention (Broadbent, D.E. Decision and Stress. Academic Press, London, 1971). This makes a distinction between "pigeonholing" (response set) and "filtering" (stimulus set). The present findings are compatible with a schizophrenic defect at the pigeonholing stage. In contrast, the evidence for a defect in filtering specific to schizophrenia remains weak, due to the use of inappropriate control groups in a number of studies reviewed.

Attention↗