The effect of African-American acculturation on neuropsychological test performance in normal and HIV-positive individuals. The HIV Neurobehavioral Research Center (HNRC) Group.

Two studies were conducted to examine the relationship of acculturation to neuropsychological test performance among (1) medically healthy, neurologically normal African Americans (N = 170); and (2) HIV positive (HIV+) subgroups of African Americans and Whites (Ns = 20) matched on age, education, sex, and HIV disease stage. Acculturation was measured through self report for all participants, and linguistic behavior (Black English use) was assessed in a subset of medically healthy individuals (N = 25). After controlling for the effects of age, education, and sex, medically healthy African Americans who reported less acculturation obtained lower scores on the WAIS-R Information subtest and the Boston Naming Test than did more acculturated individuals. Black English use was associated with poor performance on Trails B and the WAIS-R Information subtest. HIV+ African Americans scored significantly lower than their HIV+ White counterparts on the Category Test, Trails B, WAIS-R Block Design and Vocabulary subtests, and the learning components of the Story and Figure Memory Tests. However, after accounting for acculturation, ethnic group differences on all measures but Story Learning became nonsignificant. These results suggest that there are cultural differences within ethnic groups that relate to neuropsychological test performance, and that accounting for acculturation may improve the diagnostic accuracy of certain neuropsychological tests.

Motivation: cause or confound in information processing/intelligence correlations?

The goal of the present study was to determine whether correlations between information processing scores and intelligence can be explained in terms of between-subject motivational differences. One hundred and nine male and female volunteer college students were tested on a battery of microcomputerized cognitive tests. One hundred of these subjects returned for a second session in which they were randomly assigned to an incentive or no-incentive condition and then retested. The effort expended on the tests was measured via heart rate, skin conductance, and a self-report questionnaire. Criterion measures, including the Advanced Otis-Lennon Test of Mental Abilities and Advanced Raven Progressive Matrices were also taken. The findings revealed that incentives had relatively modest effects on performance. In no case, however, did incentives affect the overall IQ-performance correlation for the tests used in the battery. These results support the view that correlations between information processing scores and intelligence reflect common mental capacities, rather than some affective variable such as motivation.

Negative and positive cognition in depressed and nondepressed chronic-pain patients.

Several studies have suggested that depressed pain patients evidence more cognitive distortion than nondepressed pain patients and healthy controls. Although these studies have generally supported notions relating cognitive distortion to depressive functioning, other aspects of dysfunctional cognition have not been assessed in the chronic-pain population. The present study examined negative and positive automatic thoughts and attributional style in depressed pain patients, nondepressed pain patients, and healthy controls. Depressed chronic-pain patients were found to exhibit significantly more negative automatic thoughts than nondepressed pain patients and healthy controls. Conversely, nondepressed chronic-pain patients reported significantly more positive automatic thoughts than did depressed patients and healthy controls. No significant differences were found for attributional style. These results suggest that different cognitive-behavioral interventions might be considered for depressed compared to nondepressed chronic-pain patients.

Thought disorder and associative cognitive dysfunction in the first-degree relatives of adult schizophrenics. A reply to Romney.

Contrary to both theoretical and empirical findings, Romney equates associative cognitive dysfunction with other manifestations of thought disorder. Moreover, he overstates the case for the documentation of thought disorder in the families of schizophrenics. We discuss his reaction to Callahan and Saccuzzo in the context of four major issues. We conclude that the evidence for thought disorder in the families of schizophrenics is weak and inconclusive. We call for more rigorous research as well as the exploration of viable alternatives.

MMPI subgroups and affective disorder in chronic pain patients.

Patients with chronic pain syndromes are commonly depressed. Chronic pain populations also contain distinct subgroups of personality profiles as defined by the MMPI. To assess the relevance of personality subtype to affective disorder we determined the relationship of psychiatric diagnoses defined by Research Diagnostic Criteria (RDC) to MMPI subgroups in a sample of hospitalized patients with predominantly chronic low back pain. RDC psychiatric diagnoses for the sample were major depression (44.2%), minor depression (19.2%), other psychiatric disorder (13.5%), and no mental disorder (21.6%). Patients satisfying RDC criteria for major depression were significantly associated with discrete MMPI personality subtypes. No other psychiatric diagnoses were significantly associated with distinct personality subgroups. No relationship was observed between personality profile and presence of demonstrable organic etiology for pain. These findings indicate that behavioral and pharmacological interventions directed at depression as well as pain are important in the treatment of chronic pain populations, especially in selected subgroups.

Associative intrusions in the verbal behavior of the first-degree relatives of adult schizophrenics. A preliminary study.

The first-degree blood relatives of schizophrenics were compared to a matched control group on a psychometrically matched test of responsiveness to associative intrusions. The groups differed on the subtest containing an associative alternative but not on the equally difficult subtest free of associative distractors. Results were consistent with the hypothesis that an overresponsiveness to associative distractors, well documented in schizophrenics, may also be a characteristic of their nondisturbed first degree blood relatives. The possible existence of cognitive markers in the relatives of schizophrenic patients that might indicate familial psychopathology was supported. Limitations of the present preliminary findings, as well as the case for additional investigation of the cognitive behavior of the first-degree relatives of schizophrenics, are discussed.

Information-processing abnormalities: trait- and state-dependent components.

Schizophrenics were compared to schizoaffective, bipolar, and nonpsychotic depressed patients in a visual masking paradigm in which an informational target stimulus was followed at varying intervals by a noninformational masking stimulus. In limiting the availability of the sensory signal provided by the target stimulus, the mask was used to probe how information from the environment enters and is processed by the central nervous system. The use of the masking paradigm was originally based on the hypothesis that thought disorder is a result of a more primary dysfunction in the processes that precede and result in thought. Results confirmed previous findings of a performance deficit in the schizophrenics when compared to nonpsychotic controls. Schizoaffective and bipolar patients also showed evidence of impaired processing, however. Results were interpreted in terms of a trait/state formulation in which impaired information processing is seen as a fundamental trait of schizophrenia spectrum disorders and as a state that can covary with psychotic illness in general. A unifying concept centers on the effects of psychopathological conditions on an individual's processing resources that results in either underprovision or overprovision of information from sensory input to complex cognitive operations dependent on the cerebral cortex. Findings from a variety of paradigms are consistent with those of the masking paradigm in revealing that the processing deficits of schizophrenics are time dependent and occur in the 500 ms following stimulus input.

Schizotaxia, information processing and the MMPI 2-7-8 code type.

The relationship between the 2-7-8 MMPI code type and schizotaxia was investigated. College students whose Minnesota Multiphasic Personality Inventory profiles revealed a 2-7-8 code were compared to an elevation-free group on a visual information-processing task. The 2-7-8 group exhibited a processing deficiency similar to that previously found for schizophrenics and in-patient schizotypal personalities, supporting the construct validity of the 2-7-8 code as a measure of schizotaxia.

Interhemispheric visual masking.

Backward masking functions were evaluated in a paradigm in which target and masking stimuli were presented to opposite cerebral hemispheres using separate peripheral pathways. Backward masking occurred dichoptically when the target and mask were projected to opposite hemispheres. These findings indicated that some effective masking mechanisms are mediated by interhemispheric interactions independent of retinal phenomena.

The time course of information-processing deficits in schizophrenia.

A visual backward masking task was used to specify the time course of the information-processing dysfunction in 19 schizophrenic patients and 15 matched control patients using novel interstimulus intervals. The authors found that the information-processing deficit in schizophrenic subjects occurred at interstimulus intervals of greater than 60 msec and less than 500 msec. These data are compared with the results of evoked-potential and other psychophysiological studies. The visual-processing impairment is specific and time-linked rather than a reflection of the effects of gross psychopathology or medication in schizophrenic individuals.

Information processing in borderline patients.

An experiment was conducted to determine whether depressed borderline patients could be distinguished from normal controls and psychotic patients on the basis of a visual backward masking task that measures speed of information processing. Results showed that a) borderline patients could not be distinguished from normal controls on the information-processing task; b) both the borderline patients and the normal controls were superior to psychotic patients with diagnoses of major depressive, schizoaffective, and manic disorders; and c) among the three psychotic groups, the schizoaffective subjects were the most impaired. The data support the idea that borderline patients have normal-range information-processing functions. In distinction, all three psychotic groups showed disruption of this fundamental ego function by which information is processed. The results of related experiments indicate that schizotypal patients (in distinction to borderline patients) are abnormal information processors. Taken together, these findings support the contention that the schizotypal/borderline distinction is valid.

The schizophrenia spectrum: a study of the relationship among the Rorschach, MMPI, and visual backward masking.

Compared 20 Ss within the schizophrenia spectrum and 20 non-schizophrenia spectrum controls in terms of their MMPI and Rorschach performance. Ss also were studied in terms of their ability to identify a briefly exposed visual stimulus when it was followed by a noninformational mask stimulus and when it was not. Ss did not differ on the MMPI or on their ability to identify an unmasked target stimulus. They differed significantly in the number of deviant verbalizations, a special scoring category of the Rorschach. Ss also differed in their ability to identify the briefly exposed stimulus when it was followed by the noninformational mask. Results indicated a relationship among the deviant verbalization, the masking procedure, and the schizophrenia spectrum.

Speed of information-processing and structural limitations by mentally retarded and dual-diagnosed retarded-schizophrenic persons.

Three experiments were conducted in an investigation of information-processing capabilities of mentally retarded adults, nonretarded children (mental age control), and nonretarded adults (chronological age control). In all experiments, one of two target stimuli was presented to the center and to the right or left of central fixation. Subjects were required to detect the presence of a stimulus in a yes-no forced-choice paradigm (Experiment 1), identify which of the two targets had been presented in a forced-choice discrimination paradigm (Experiment 2), or distinguish between the targets in a forced-choice discrimination task when the target was preceded by, presented stimultaneously with, or followed by a patterned noninformational masking stimulus. The findings support the theory of a structural defect in mentally retarded persons that results in slow information-processing.

Luminance level and onset sequence of a pre- and post-exposure adapting field affects recognition of masked and unmasked stimuli.

Three experiments were conducted to evaluate the effects of the luminance level of a pre-/post-exposure field and onset sequence of a post-exposure field on briefly exposed visual stimuli for 13 male and 13 female undergraduate college students. Results showed that identification of a briefly exposed informational test stimulus as well as masking effects (the minimum interval between an informational test stimulus and non-informational backward visual noise mask) were both influenced by the luminance of the pre-exposure field and onset sequence of the post-exposure field.

The relationship of depression and thought disorder in pain patients.

In the recent literature, the presence of thought disorder occurring with depression has been both supported and contradicted. In order to clarify the relationship of thought disorder and depression this study examined three areas of cognitive function in depressed and non-depressed groups drawn from pain patients and normals. Subjectively, depressed subjects had significant deficits in abstraction, associative tightness, and speed of information processing. Across all subjects, increasing cognitive impairment in all three dimensions correlated significantly with increasing severity of depression. Pain per se and analgesics did not account for the results. There were several significant correlations between the cognitive measures, suggesting a general process mediating the thought disorder associated with increasing levels of depression. The results support and extend the known relationship of thought disorder and depression.

Backward contralateral masking by light and by random pattern.

Letter-stimuli as targets were presented to the right or left visual fields and followed either by a flash of light or by a flash of light plus a patterned mask. The patterned mask always appeared in the opposite visual field of the letter targets. Analysis showed that masking occurred for both types of masks but that subjects produced more errors at each of five intervals between onset of the target and onset of the mask for the flash of light plus a patterned mask in the opposite visual field than for the flash of light alone. A pattern mask, when presented to the opposite visual field of a target stimulus, interferes with target processing at short target-mask intervals. These findings suggest that central backward masking may involve target-mask interactions beyond the visual cortex (Area 17).

Effect of antipsychotic medication on speed of information processing in schizophrenic patients.

The authors evaluated the effects of antipsychotic medication and schizophrenia on speed of information processing. Medicated (N - 20) as well as unmedicated (N = 16) schizophrenic patients showed more evidence of slow information processing than did depressed control subjects (N = 20). The medicated schizophrenic patients had higher levels of general psychopathology but also showed superior information processing speed compared with the unmedicated schizophrenic patients. These data confirm that the schizophrenic patients are slow information processors and that antipsychotic medication probably does not cause, and may actually reverse, slowness of information processing in schizophrenic patients.

Visual masking with presentations in same and opposite visual fields: evidence for contralateral masking.

Three experiments were conducted in a preliminary attempt to study the effects of presentations of an informational target stimulus to the right or left visual fields when the target was either preceded or followed by a noninformational masking stimulus and when the mask was presented to the same or opposite visual field of the target. Results indicated that masking was more effective in the same than in the opposite visual field but that masking of the opposite visual field was feasible for both forward and backward masking. Laterality effects were also found for forward and backward masking, with a modest advantage of the right visual field (left hemisphere) in both cases. Limitations of the data and directions for future research were discussed.

The effect of mental retardation and schizophrenia on information processing.

Research Diagnostic Criteria-diagnosed schizophrenic persons with average intelligence and dual diagnosis mentally retarded schizophrenic persons were tested in a forced-choice letter discrimination task in order to examine the relationship between schizophrenia and retardation from the standpoint of information-processing theory. The subjects consisted of eight schizophrenic persons of average or better intelligence, eight mentally retarded schizophrenic persons, and a control group of eight Research Diagnostic Criteria-diagnosed minor depressive individuals who were matched with the nonretarded schizophrenic group for intelligence. The groups did not differ significantly on the minimum exposure duration needed to identify an unmasked target stimulus at criterion levels of accuracy. When masked stimuli were employed, however, the depressive group obtained significantly more correct detections than both schizophrenic groups. More importantly, the performance of the two schizophrenic groups did not differ significantly. Our data indicated that schizophrenic deficits in information processing are independent of intellectual factors. Thus, vulnerability to a masking stimulus in schizophrenic persons can be attributed to the pathology of schizophrenia. This vulnerability indicates that schizophrenic patients are slow information processors.