Neuropsychological test performances of paranoid schizophrenic and brain-damaged patients.

Predicted that simple tests that require attention and motor speed would be able to differentiate paranoid schizophrenics from brain-damaged patients better than more complex, problem-solving neuropsychological tests. The strategy was to improve discrimination between schizophrenic and brain-damaged patients by selecting a schizophrenic subgroup with a recognized cognitive strong point. Fourteen organic, 14 paranoid schizophrenic, and 14 nonpsychotic psychiatric patients matched for sex, education, and IQ were tested. As predicted, the attention and speed measures differentiated the brain-damaged and paranoid groups, while the four more complex measures from the Halstead-Reitan Battery did not separate the groups. There were no significant differences between the two psychiatric groups.     

MMPI profiles of brain-damaged and schizophrenic subjects

MMPI mean profiles for matched groups of 50 brain-damaged and 50 schizophrenic Ss from a short-term hospital were compared. The profiles are quite different. F tests demonstrated that the Sc scale best differentiated the two groups at far beyond the .01 level, and scales F, PA and PT also differentiated the two groups beyond the .01 level. A cut-off point of 80 on the SC scale correctly classified 78% of the two groups. Neither the 2-9 nor the 1-3-9 profile occurred a sufficient number of times in either group to be of any help in diagnosis.     

Relative efficacy of the Sc-O, P-O, P-N, and Sc MMPI scales in differentiating brain-damaged, brain-damaged schizophrenic, schizophrenic, and somatoform disorders in an outpatient setting

This study examined the efficacy of the Schizophrenic-Organicity (Sc-O), Psychiatric-Organic (P-O), the Pseudo-Neurological (P-N), and the Schizophrenia (Sc) MMPI subscales in differentiating the following four groups of outpatients: brain-damaged (n = 35), brain-damaged schizophrenics (n = 10), non-brain-damaged schizophrenics (n = 15), and somatoform disorders (n = 45). Both unmatched and matched samples were used in the analysis, and cut-off scores were obtained. In an unmatched sample, results suggested that the Sc scale was useful in differentiating brain-damaged schizophrenics from brain-damaged and somatoform disorders. With matched samples, the Sc differentiated brain-damaged schizophrenics well from other clinical groups, while the P-O scale differentiated the non-brain-damaged schizophrenics from brain-damaged and somatoform disorders. Furthermore, the P-N scale discriminated brain-damaged schizophrenics from non-brain-damaged schizophrenics, while the Sc-O scale was no longer significant. Results suggest that caution should be used in generalizing from previous studies (which used inpatient samples) to outpatient populations.     

Event-related potentials and item recognition in depressed, schizophrenic and alcoholic patients

Auditory event-related potentials (ERPs) to pure tones and performance on a measure of item recognition were compared in 20 controls, 14 alcoholics, 20 depressed and 21 schizophrenic patients. Compared with normal controls, P2 and N2 were delayed and of diminished amplitude in the psychopathological groups. Increased amplitude of P1 in alcoholics, diminished N1 in depressed patients, increased latencies of N1 in schizophrenics and N2 in alcoholics were pathology-specific. Unusual patterns of response in the item recognition test (elevated intercept and flattened slope) and its relationship with ERPs distinguished the diagnostic groups from the controls. Support for the preferential involvement of the left hemisphere in schizophrenia and of the right hemisphere in depression was found. Disinhibition of CNS activity in the response of alcoholics (increased P1 and delayed P3) was indicated. The findings suggested that discriminant analysis of auditory ERPs to simple, pure tones, in conjunction with psychometric data significantly differentiated pathologic groups from each other and from controls.     

A process approach to the Bender-Gestalt test and its use in differentiating schizophrenic, brain-damaged, and medical patients

Developed a processing model that would account for the shifting of attention that occurs as individuals copy Bender-Gestalt designs. Process-oriented variations of the Bender-Gestalt test were designed that emphasized each of the three processes hypothesized to contribute to Bender-Gestalt performance: Perceptual-motor integration, attentional factors, and short-term memory. A standard Bender-Gestalt and the three variations were administered to 24 schizophrenics, 24 brain-damaged patients, and 24 medical patients, matched for intelligence and sex. Protocols were scored blindly by the Pascal-Suttell and Hain methods. Discriminant function analysis based upon the four versions of the Bender-Gestalt test classified patients as schizophrenic or brain-damaged at a significantly higher rate than the standard Bender-Gestalt scored by either the Pascal-Suttell or Hain system.     

A comparison of the effectiveness of MMPI indices in the discrimination of brain-damaged and schizophrenic patients

Assessed the effectiveness of 22 published MMPI procedures to differentiate organic brain syndrome (OBS) from schizophrenic (Sc) patients. Generally, each procedure previously has been suggested to have some effectiveness in making this differentiation. When assessed across studies, however, the S groups have differed on so many relevant variables (age, sex, clinical setting, etc.) that direct comparisons of their relative effectiveness cannot be made. In the current study the accuracy rates are presented for each of the 22 discrimination procedures with a sample matched on age, education, and IQ and also with an unmatched sample, all selected from the patient population at a neuropsychiatric setting. With the matched sample the Hs-Pt Index (Watson, Plemel , & Jacobs, 1978) and the Sc-O Scale, Unweighted Long form (Watson, 1971) reached statistical significance (p less than .10). With the unmatched sample both of the above procedures plus the OBS Signs procedure ( Markowitz , 1973) and P-O Scale (Watson & Plemel , 1978) reached statistical significance (p less than .10). Overall accuracy rates of those procedures found to be statistically significant ranged from 61.5 to 70.0%. These accuracy rates compare favorably to those obtained with more complex and time-consuming neuropsychiatric batteries.     

Differential relationships of age and education to WAIS subtest scores among brain-damaged and control groups.

The 11 subtests of the WAIS were compared to the attribute variables of age and education in a brain-damaged group and a non-brain-damaged (control) group. Because of the validity information available for the WAIS, the subtests for the WAIS rather than the WAIS-R were studied. Data analyses compared the level of age and education (each group subdivided at the median) on WAIS subtest scores and the correlations between attribute variables and subtest scores. The results revealed a number of differences between the two groups, with age and education having a weaker and less consistent relation to WAIS subtest scores in the brain-damaged group than in the control group. The findings suggest that the relationships between attribute variables and psychological test scores are complex, and that adjusting or transforming raw scores for brain-damaged subjects according to tables based upon non-brain-damaged subjects may produce erroneous data.     

Random number generation by normal, alcoholic and schizophrenic subjects

Controls (N = 45), schizophrenics (N = 20) and alcoholics (N = 23) were asked to choose at random a number between 1 and 10, 100 times. The correlation matrices of five different randomization indices were used to study within group variation; these matrices were similar for the normal and alcoholic groups, but very different for the schizophrenic group. The differences between the three groups were studied by canonical analysis and, in terms of the canonical variables, the mean performance of the normal group is clearly discriminated from that of the alcoholic and schizophrenic subjects.     

Further evidence that concerns the validity of an MMPI key for separation of brain-damaged and schizophrenic patients

This study attempted to cross-validate an MMPI Key for the separation of brain-damaged and schizophrenic inpatients. MMPI profiles generated by 20 males with a variety of documented brain dysfunctions were compared to those of 20 heterogenous male schizophrenics. The groups were matched on the variables of age and education. The procedure provided 82.5% correct classification, which included 85% correct schizophrenic identification and 80% correct brain-damage identification. The Key was recommended for use as a rough screening device or as a supplement to appropriate neuropsychological procedures.     

Performance of alcoholic and brain-damaged subjects on the Luria memory words test

Verbal memory was evaluated in groups of 36 community controls, 50 pseudoneurological controls, 50 alcoholics, and 50 brain-damaged patients. All participants were men between the ages of 22-61. Groups did not differ in age or educational levels (F < 1). Groups were compared on their performance on the Luria Memory Words Test. Dependent variables included the number of correct words over learning trials, the trial of best performance, and the number of words recalled at three delayed trials (2, 8, and 30 min after learning). Brain-damaged subjects were inferior to community controls on all measures. Pseudoneurological controls were inferior to community controls on delayed recall, but were equivalent on measures of learning. Alcoholics were inferior to controls on measures of learning but did not differ on measures of recall. Implications regarding the underlying deficit in alcoholics' verbal memory, the use and interpretation of the Luria Memory Words test, and the use of pseudoneurological patients as controls are discussed.