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Biomedical subjects

L J Chapman

Publications and source records attributed to L J Chapman.

At least 55 records · Page 3Linked to original sources
PubMed1984

Impulsive nonconformity as a trait contributing to the prediction of psychotic-like and schizotypal symptoms.

A 51-item true-false Impulsive Nonconformity Scale was constructed to measure impulsive antisocial behavior of the sort often reported in the premorbid adjustment of some psychotics. Schizophrenics and schizoaffective patients (N = 46) scored higher on the scale than control (N = 76). An experimental group of 120 aberrantly high-scoring (2 SDs above the mean) college students and 176 control subjects were interviewed using modified versions of Weissman and Paykel's Social Adjustment Scale interview and Spitzer and Endicott's Schedule for Affective Disorders and Schizophrenia-Lifetime Version (SADS-L). The experimental subjects reported more antisocial and nonconforming behaviors than control subjects, supporting the construct validity of the scale as a measure of impulsive nonconformity, and reported more psychotic or psychotic-like experiences, more schizotypal experiences, and more depressive and manic or hypomanic symptoms, suggesting that a portion of the experimental subjects may be at elevated risk for psychosis and/or major affective disorder. Subjects who score aberrantly high on both the Impulsive Nonconformity Scale and our earlier Perceptual Aberration-Magical Ideation Scale are more aberrant on several other measures of schizophrenic-like cognitive slippage than are subjects who score high on only one of the two scales.

Adult↗
PubMed1983

Reliability and the discrimination of normal and pathological groups.

The authors of a recent article (Neufeld, R. W. J., and Broga, M. I. Evaluation of information sequential aspects of schizophrenic performance. II. Research strategies and methodological issues. J. Nerv. Ment. Dis., 169: 569-579, 1981) questioned the usefulness of considering reliability and other psychometric characteristics of tasks in the comparison of the pathological and normal groups on the abilities measured by the tasks. They supported their conclusion by a reanalysis of data published by Chapman and Chapman (Chapman, L.J., and Chapman, J.P. Problems in the measurement of cognitive deficit. Psychol. Bull., 79: 380-385, 1973). We contend that their conclusion was based on an inappropriate analysis of the data with a neglect of relevant psychometric principles.

Humans↗
PubMed1980

Physical anhedonia, perceptual aberration, and psychosis proneness.

Two groups of hypothetically psychosis-prone subjects were chosen from among college students who scored deviantly high on scales of Physical Anhedonia (n = 50) or Perceptual Aberration (n = 65). Scores on these two scales had a small negative correlation, indicating that the scales identify different sets of deviant subjects. These experimental subjects and a control group (n = 66) were interviewed using a modification of the Schedule for Affective Disorders and Schizophrenia--Lifetime Version. A second interview covered social and academic adjustment. Psychotic and psychotic-like symptoms (attenuated forms of psychotic experiences) were scored on a recently devised scale of deviancy. The perceptual aberration subjects exceeded the control subjects on each of several psychotic-like experiences (auditory and visual experiences, thought transmission, passivity experiences, aberrant beliefs), as well as on depression, hypomania, social withdrawal, problems of concentration, deviances in communication and speech, and a composite score for schizotypal features. Anhedonics did not differ from controls on psychotic-like experiences but were more socially withdrawn, had less heterosexual interest and activity, and scored higher on the composite score of schizotypal features. The findings support the hypothesis that the scales identify persons who are at risk for psychosis but probably for different psychoses.

Adult↗
PubMed1980

Scales for rating psychotic and psychotic-like experiences as continua.

Although psychotic symptoms are usually viewed as dichotomous events, both patients and nonpatients often report isolated psychotic experiences as well as psychotic-like experiences, the latter being attenuated versions of psychotic experiences. College students, previously identified as probably at high risk for psychosis, were interviewed using a modified Schedule for Affecting Disorders and Schizophrenia--Lifetime Version (SADS L). Eighty types of deviant experiences reported in the interviews fell into six categories: transmission of one's own thoughts, passivity experiences, thought withdrawal, voice and other auditory experiences, aberrant beliefs, and visual experiences. The 80 types of experience were rated on deviancy by six expert judges (coefficient alpha of raters = .94). The median ratings of the six judges were used to construct a manual. Two pairs of raters used the manual to rate excerpts of interview and obtained reliabilities of .78 and .81. This manual should be useful in evaluation of psychotic-like experiences, especially in studies of individuals believed to be at high risk for future development of clinical psychosis.

Adolescent↗
PubMed1979

Recent advances in the study of schizophrenic cognition.

This is a review of some important areas of recent research on schizophrenic cognition. Foci of the review include: (1) The attempt to identify measures of thought disorder that may serve as markers of vulnerability to schizophrenia. (Measures of attention and of cognitive deviancy on the Rorschach have been prominent in this line of work.) (2) Controlled clinical description of schizophrenic thought disorder. (3) Studies of schizophrenic defects of memory.

Adult↗