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Biomedical subjects

J R Schuck

Publications and source records attributed to J R Schuck.

4 recordsLinked to original sources
PubMed1989

Backward masking, information processing, and schizophrenia.

Many researchers have used backward masking to examine information-processing speed in schizophrenic subjects. The validity of this approach rests upon two main assumptions. One is that the mask effectively limits the time a previously presented stimulus is available for processing. The other is that the components of the masking mechanism in schizophrenic subjects are comparable to those in control groups. It is argued that the masking procedures used in these studies fail to meet either assumption. Alternative interpretations of these investigations, however, suggest important hypotheses for further research in our quest to understand information-processing deficits associated with schizophrenia.

Humans↗
PubMed1985

Construct validity of various memory testing procedures.

The construct validity of Wechsler Memory Scale Logical Memory, Paired Associate Learning and Visual Reproduction subtests was evaluated, as well as the validity of the Benton Visual Retention Test, and the two memory factor scales of the Luria-Nebraska Neuropsychological Battery (LNNB). The results of a series of factor analyses based on test performances of 102 subjects indicated that delayed reproduction measures of visual memory were more valid than the traditional immediate reproduction administrations, which were more closely associated with visual-perceptual-motor abilities. Construct validity was also demonstrated for Logical Memory and Paired Associate Learning. Although both LNNB measures loaded on a memory factor, item heterogeneity and brief sampling of items raised serious questions about the clinical utility of these scales.

Adult↗
PubMed1979

A study of schizophrenics' ability to localize the source of a sound.

Twelve process, nonparanoid schizophrenics, 12 nonschizophrenic psychiatric controls, and 12 normal controls were given an auditory localization task. Performance was measured by the number of correct localizations and was studied as a function of three variables: diagnosis, position of the apparatus in relation to the subject's median plane (right or left), and the degree of displacement of the auditory stimulus from a fixation point (4.5 degrees, 3.0 degrees, and 1.5 degrees). A three-way analysis of variance with two repeated measures resulted in a significant main effect for each of the three independent variables. Orthogonal comparisons indicated no difference in performance between normal and psychiatric controls but a significant difference between schizophrenics and the combined controls. The degree of displacement of the auditory stimulus resulted in a significant linear trend in performance. There were no significant interactions. The present findings strongly suggest that process, nonparanoid schizophrenics suffer from a specific deficit in auditory localization.

Adult↗