The role of right hemisphere dysfunction in psychiatric disorders.
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Cerebral Cortex↗
Biomedical subjects
J Cutting
Publications and source records attributed to J Cutting.
Soft contact lenses with partial occlusion for prolonged lateralization of visual input.
Techniques for prolonged lateralized presentation of visual material using specially designed contact lenses have been devised but with limited applicability. We have been able to manufacture soft contact lenses which occlude either the right or left visual field by applying a commercially available dye to the relevant portion of the lens. The resultant field defect was confirmed electrophysiologically. The lenses would appear to have numerous applications in experimental psychology in the study of cerebral asymmetries.
Contact Lenses, Hydrophilic↗
Lateralized anomalous perceptual experiences in schizophrenia.
Four cases of schizophrenia are described, in which subjects reported anomalous perceptual experiences confined to one visual field, in all cases the left visual field. The pattern, content and laterality of such anomalous perceptions point to the presence of right hemisphere dysfunction in schizophrenia. Further evidence to this effect comes from examining the type of anomalous perceptual experiences reported by subjects with focal lesions in either hemisphere. Those with right hemisphere damage but not those with left hemisphere damage report almost identical experiences to those seen in the 4 schizophrenics described here.
Adult↗
Delusional misidentification and the role of the right hemisphere in the appreciation of identity.
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Awareness↗
Preference for denotative as opposed to connotative meanings in schizophrenics.
Twenty schizophrenics, 20 manics and 20 subjects with a depressive illness were asked to select the pair of words from a group of three which went together best. The groups of words were arranged such that potential pairings reflected shared denotative (e.g., linked by being antonyms) or shared connotative meaning (e.g., linked at a metaphorical level). The measure "denotative-based--connotative-based selections" was significantly lower in schizophrenics than manics and just failed to significantly distinguish schizophrenics from depressives. In a second experiment schizophrenics were significantly different from the depressives in showing less inclination to select a metaphorical meaning to an ambiguous adjective in a sentence. It is suggested that these results arise because the schizophrenic relies more on their left hemisphere lexicon in carrying out such semantic tasks.
Adult↗
Prosodic comprehension and expression in schizophrenia.
Schizophrenics, manics, depressives and normal subjects (15 in each group) were tested for their ability to understand and express the prosodic quality of speech. Sentences in which one word was stressed (stress prosody comprehension) or in which a particular emotion was conveyed (emotional prosody comprehension) were taped and played to subjects to test their comprehension. Subjects were then asked to read out a list of sentences either stressing a nominated word (stress prosody expression) or conveying a nominated emotion (emotional prosody expression), and their efforts were rated by a panel of normal raters. The main results were 1) that schizophrenics were significantly inferior to the normal group, but equivalent to manics and depressives on emotional prosody comprehension; 2) schizophrenics were significantly inferior to all other groups on emotional prosody expression; and 3) all four groups were equivalently proficient on stress prosody comprehension and expression. The results are interpreted as lending support for the idea that there is an underlying right hemisphere dysfunction in schizophrenia.
Adult↗
Relationship between cycloid psychosis and typical affective psychosis.
This article describes the clinical features and outcome of a series of 73 inpatients who fulfilled Perris' criteria for cycloid psychosis. It is argued that although the cases differ from either schizophrenia or affective psychosis in some ways, the condition of cycloid psychosis is best regarded as an atypical variety of affective psychosis.
Affective Disorders, Psychotic↗
Impaired ability of schizophrenics, relative to manics or depressives, to appreciate social knowledge about their culture.
Twenty schizophrenics, 20 manics, and 20 depressives were given two sets of multiple choice questions, one testing the subject's social knowledge of how people tend to act in a social situation and the other tapping their knowledge of events or objects which are relatively free of a social component. Schizophrenics were significantly impaired on the former set of questions relative to manic, and were significantly worse on both than depressives. It is suggested that these results represent an objective measure of the social naïvete of schizophrenics. The significant difference from manics indicates that the results are not merely the general effects of psychosis, particularly because the manics performed worse on an attentional test than the schizophrenics.
Adult↗
Subjective experience of schizophrenia.
A standardized assessment of the subjective experience of schizophrenia and depression was developed in three stages: (1) An open-ended interview covering changes in nine areas of psychological functioning was given to acute, remitted, and chronic schizophrenic patients, and to depressed patients. (2) On the basis of their replies, a structured interview was given on two separate occasions close in time to 20 remitted schizophrenic patients by two different interviewers to test interrater reliability, and to the same 20 remitted patients 6 months later by one interviewer to test intertemporal reliability. (3) The most reliable items were retained in a final version, from which the replies of a new group of 20 remitted depressed and the 20 remitted schizophrenic patients could be compared. Despite the long interval that usually had elapsed between the first episode of illness and the time of questioning, most patients gave a detailed account of their experiences that did not vary much either 6 months later or in an interview by a different psychiatrist. The most reliable items concerned changes in perception, and these also best distinguished the experiences of schizophrenia from those of depression. Perceptual dysfunction appears to be the most invariant feature of the early stage of schizophrenia, but a qualitative disturbance of thinking also occurs.
Acute Disease↗
Schizophrenic inability to judge facial emotion: a controlled study.
The ability of schizophrenics to judge facial emotion was examined using a new test derived to remedy methodological inadequacies in previous studies. The derivation procedure of the test is described. Five groups of 20 subjects each took part: acute schizophrenics, chronic schizophrenics, schizophrenics in remission, in-patients with depressive illness and normal subjects. They were asked to make a dichotomous emotion judgement ('happy' or 'sad') about a set of photographed faces: and then to make a dichotomous non-emotion judgement ('old' or 'young') on a set of photographs chosen from the same original pool to form a task of equal difficulty and discriminating ability. It was predicted, from previous studies, that acute schizophrenics would be specifically impaired on judging emotional expression in faces. Instead, they were found to be impaired on both an emotion and a non-emotion task on photographs of faces when these tasks were matched for difficulty and discriminating ability. They were significantly worse than remitted schizophrenics and normal subjects for both tasks, and for emotion, significantly worse then depressed subjects as well. The findings are considered in the light of current theories of visual processing in schizophrenia and of the neuropsychology of face processing.
Adult↗
Gestalt theory and psychiatry: discussion paper.
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Europe↗
Schizophrenic thought disorder. A psychological and organic interpretation.
It is suggested that schizophrenic thought disorder comprises four relatively independent components: delusion; intrinsic thinking disturbance; formal thought disorder; and deficient real-world knowledge--a new concept. Schizophrenic and neurotic control subjects were given tests of thinking, perception, appreciation of conversational discourse, and social and practical knowledge. Not all deluded schizophrenics had intrinsic thinking disturbance. Those that did tended to have overinclusive categorisation as the most apparent deficit. Formal thought disorder was associated with a poor performance on the test of conversational discourse. The most striking result was that 75% of schizophrenic patients were markedly deficient, relative to neurotic patients, on their knowledge of everyday social issues.
Adult↗
The nature of overinclusive thinking in schizophrenia.
Schizophrenics were compared with neurotic controls on four tests of categorical thinking in an attempt to discover the nature of overinclusive thinking. The tests provided both verbal and nonverbal measures of conceptual loosening, the proportion of out-of-category items, distortion of the internal structure of a category and any tendency towards overcategorization. The results showed that schizophrenics were relatively worse on nonverbal than on verbal categories with, in particular, a greater degree of conceptual loosening and a tendency towards overcategorization. The most striking abnormality emerged during observation of the actual sorting strategy itself. Schizophrenics tackled the task in a way which suggests that they lack the ability to form a Gestalt of the task.
Adult↗
The phenomenology of acute organic psychosis. Comparison with acute schizophrenia.
The psychopathology of acute organic psychosis was investigated by interviewing 74 patients using the Present State Examination (PSE). Their delusions, perceptual disturbance, thought disorder, and emotional disorder were categorised and then compared with those seen in 74 acute schizophrenics. In acute organic psychosis there was a particular pattern to the delusions, perceptual disturbance, and thought disorder, which was quite unlike that seen in acute schizophrenia. These results have implications for theories claiming that schizophrenia is an organic psychosis. It is suggested that the psychopathology in acute organic psychosis has very different origins from that seen in schizophrenia.
Acute Disease↗
Personality and psychosis: use of the Standardized Assessment of Personality.
The Standardized Assessment of Personality, a semistructured interview for use with an informant, was used with a relative or a close friend to determine the premorbid personality of 100 consecutive patients admitted with major psychiatric disorders - major affective disorders (18 manics, 35 depressives), schizophrenia (28) and other functional psychoses (19). Forty-four per cent of the entire sample had an abnormal personality as defined by the presence of one of 10 prominent traits to a marked degree. A further 6% had the same traits to a lesser degree. The proportion of patients with an abnormal personality (all types) was comparable across the four diagnostic groups (manics 39%, depressives 54%, schizophrenics 39%, other functional psychotics 37%). However, if one included all traits (marked and mild), patients with an affective disorder had more between them than did the non-affective groups. This difference was largely accounted for by cyclothymic, anxious and obsessional traits. The schizophrenics and other functional psychotics had surprisingly few prominent traits and, in particular, a schizoid personality rarely preceded a schizophrenic illness.
Adult↗
The nature of the abnormal perceptual experiences at the onset of schizophrenia.
Sixty schizophrenics and 40 depressives in remission from the floridly psychotic phase were given a semi-structured interview concerning their abnormal perceptual experiences at the onset of their illness. About 50% of each set of subjects had experienced an alteration in the quality of their perception. However, there was a fairly characteristic pattern in each case: emotional tainting of the world around, a sense of unreality and noise sensitivity in depression; and an indefinable, qualitative change in visual perception, particularly affecting the way colours, people, space and facial expression were viewed, in schizophrenia. Of the various theories which have been put forward to explain perceptual change in schizophrenia, a breakdown in gestalt appeared to explain these findings best.
Auditory Perceptual Disorders↗
Picture perception and abstract thought in schizophrenia.
Acute schizophrenics were compared with depressed, normal and brain-damaged subjects on their ability to appreciate a meaningful picture. Their responses were measured for level of abstraction (how well the theme was conveyed), for strategy (whether details were reported before or after a global interpretation) and for appropriateness of content. Schizophrenics were less abstract than normals, more abstract than brain-damaged subjects, but no different from depressives on this measure. Their strategy was different from normals but comparable with that of depressives. The majority of schizophrenics gave inappropriate responses. It is suggested that meaningful picture interpretation might be a useful tool for evaluating the distortion of meaning which characterizes schizophrenia.
Acute Disease↗