Short-term visual memory in schizophrenics.

Hypothesized that the deficit of poor premorbid schizophrenics in backward masking is due to interference in short-term visual memory (STVM) because of the tendency to process a pattern mask as if it were a cognitive mask. The hypothesis was tested in a backward-masking picture-recognition paradigm, using data from 32 male psychiatric patients (aged 18–55 yrs) and 14 hospital personnel. The 12 good premorbid schizophrenics, 7 nonschizophrenic psychotics, and normal Ss all showed differential pattern- and cognitive-mask performance. The performances of 13 poor premorbids were equivalent on both mask types. Findings corroborate the hypothesis. It is suggested that integration of stimuli in poor premorbids' sensory storage was intact and that the disruption in processing caused by a pattern mask at 200–300 msec was due to an interference in STVM. It is concluded that the hypothesis of a deficit in perceptual organization best accounts for the apparent disruptions in poor premorbids' STVM. (70 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Task difficulty and cognitive deficits in schizophrenia.

Investigators of schizophrenic cognition often produce 2 or more tasks of differing difficulty levels by manipulating a variable that affects the accuracy of both normal and schizophrenic individuals; the investigators find that the variable also affects the difference between the groups in accuracy and conclude that the variable taps a schizophrenic differential deficit. An alternative hypothesis is that task differences in true-score variance artifactually produce the finding. For free-response tasks, group differences tend to be larger when difficulty is near 50%. The authors illustrate a new method of controlling this artifact by selecting items for hard and easy tasks on opposite sides of 50% difficulty and equidistant from it. Using this design with an anagram task, they found that schizophrenic and normal individuals differ no more on hard anagrams than on easy ones, and they propose the design for testing hypotheses concerning schizophrenic deficit on tasks that differ in difficulty. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive structure and pathology in associations of process and reactive schizophrenics.

Tested the hypothesis of different schizophrenic thought processes related to premorbid adjustment through analyses of the word associations of 20 process and 20 reactive schizophrenics. The groups (matched for age, sex, and education with scores corrected for differences in institutionalization when relevant) were predicted to show cognitive structure and type-of-deficit differences, despite a prediction of equally severe current symptoms. Significant differences in categories of healthy and pathological associations support (a) the hypotheses of differences in cognitive structure and type of deficit, and (b) the use of the process reactive distinction in research on schizophrenia. (19 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spatial working memory deficits in the relatives of schizophrenic patients

BACKGROUND: Studies in nonhuman primates provide evidence that intact spatial working memory depends on the integrity of specific areas in the prefrontal cortex. Patients with schizophrenia have been shown to be impaired on spatial working memory tasks. Relatives of schizophrenic patients show a range of cognitive deficits in the absence of clinical symptoms (eg, thought disorder, eye tracking dysfunctions). We predicted that a significant proportion of relatives of schizophrenic patients would show deficits in working memory as measured by a delayed response task. METHODS: In experiment 1, we tested 18 schizophrenic patients, 15 first-degree relatives of schizophrenic patients, and 18 normal control subjects on an oculomotor delayed response task. In experiment 2, we assessed the performance of another group of 12 first-degree relatives of schizophrenic patients and 16 different normal control subjects on a visual-manual delayed response task. RESULTS: Relatives of schizophrenic patients showed significant deficits in working memory on both the oculomotor and visual-manual delayed response tasks. CONCLUSIONS: Some relatives of schizophrenic patients are impaired on tasks that tap spatial working memory and that implicate the prefrontal system. The delayed response paradigm may be useful in elucidating the multidimensionality of the schizophrenic phenotype.     

Implementation intentions and efficient action initiation.

Implementation intentions ("If I encounter Situation X, then I'll perform Behavior Y!") are postulated to instigate automatic action initiation (P. M. Gollwitzer, 1993, 1999). In 4 studies, the hypothesis was tested that implementation intentions lead to immediate action initiation once the specified situation is encountered, even under conditions of high cognitive load. First, individuals whose action control is known to be hampered by disruptive cognitive business, such as opiate addicts under withdrawal (Study 1) and schizophrenic patients (Study 2), benefited from forming implementation intentions. Second, the beneficial effect of implementation intentions was also found in 2 experiments with university students (Studies 3 and 4) in which cognitive load was experimentally induced by using dual task paradigms. Results of the 4 studies suggest that forming implementation intentions instigates immediate action initiation that is also efficient. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stimulating transitions in moral reasoning as a function of stage of cognitive development.

Examined L. Kohlberg's proposition that cognitive development is necessary though not sufficient for moral development. The specific hypothesis tested, in a pre–posttest control group design involving 44 female adolescents (mean age 16.2 yrs), was that Moral Stage 3 Ss who have attained "early basic formal operations" are more susceptible to attempts to stimulate moral development than Stage 3 Ss who have attained only "beginning formal operations" and lack the cognitive prerequisites for moral transitions. A series of pretests (verbal reasoning and logico-physical problems, and Moral Judgment Interview) was used to obtain Ss who met the appropriate cognitive and moral criteria. The treatment exposed Ss to Stage 4 reasoning in individual role-playing situations. A moral judgment posttest followed 1 wk later. Results confirm the hypothesis, thus providing evidence for the proposition that cognitive development is necessary for moral reasoning development. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Development of Visuospatial Short-Term Memory in the Second Half of the 1st Year.

Eighty 5.5- to 12.5-month-old infants participated in 4 delayed-response procedures challenging shortterm visuospatial memory (STVM), 2 that varied the time between presentation and search and 2 that varied the number of locations. Within each type of challenge, 1 task required a gaze response and 1 required a reach response. There was little improvement in STVM performance from 5.5 to 8 months and linear improvement in the percentage correct from 8 to 12 months, with overall STVM performance accounting for 66% of the variance in age. Improvement in searching multiple locations lagged behind improvement in spanning longer delays. Memory scores did not vary for the visual and manual tasks. Perseveration was greatest for reach responses, increased with challenge, and decreased with age. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Working memory, attention, and communication disturbances in schizophrenia.

The authors hypothesized that schizophrenic communication disturbances reflect specific cognitive deficits in the areas of working memory and attention. They examined the cognitive correlates of communication disturbances, as measured by linguistic reference performance, in schizophrenic (n?=?48), bipolar (n?=?24), and nonpsychiatric control (n?=?23) individuals. Reference performance ratings in the schizophrenic patients were associated with scores on tests of working memory and attention and were not related to performance on concept formation or verbal fluency tests. In contrast, in the bipolar and nonpsychiatric individuals, reference performance was associated with concept formation and verbal fluency test scores but was not related to performance on tests of working memory. Implications with respect to the processes underlying schizophrenic communication disturbances are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual information-processing deficits in chronic schizophrenic subjects using tasks matched for discriminating power.

Compared the performance of 24 18–52 yr old hospitalized schizophrenics with that of 18–48 yr old normal controls on 3 matched visual information-processing tasks. Each of the 3 tasks involved deciding on the relative magnitude of 2 groups of letters. The 2 experimental conditions, one in which irrelevant distracting stimuli were added and the other in which response demands were increased, were matched for discriminating power with a neutral condition. Results show a significant reaction-time difference between groups on all 3 tasks, implying an overall reduction in processing speed among schizophrenics. However, schizophrenic Ss were not specifically sensitive to the effects of visual distraction or increased response complexity. Data are consistent with theories of schizophrenic deficit that emphasize the generalized nature of the cognitive disturbance and relate the level of deficit on particular tasks to the amount of capacity required to complete processing. (28 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Medial prefrontal lesions in the rat and spatial navigation: Evidence for impaired planning.

Rats with medial prefrontal cortical lesions were tested in a modified water maze navigation task. In Stage 1, the rats were trained to locate a hidden platform from a single start location. They were then subjected to a series of trials during which a second start position was used (Stage 2). In Stage 3, the rats had to navigate to a new goal location from the 2 experienced start positions. Stage 4 required the rats to navigate to the same goal as in Stage 3, starting from 4 distinct positions. Finally, a single probe trial with no platform was conducted. Rats with prefrontal lesions were impaired only during Stage 4. This deficit was specific to the 2 start positions newly introduced during this stage, suggesting a dysfunction of planning processes. This impairment might result from a working memory deficit, precluding the animal from forming an adequate representation of the whole course of movements required to reach the platform. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex differences in olfactory identification and Wisconsin Card Sorting performance in schizophrenia: relationship to attention and verbal ability

We investigated the hypothesis that different prefrontal brain systems (i.e., dorsal vs. ventral) and sex contribute differentially to cognitive deficit in schizophrenia. Performance was assessed among clinically stable, chronic schizophrenic outpatients and matched normal control subjects on olfactory identification [on the University of Pennsylvania Smell Identification Test (UPSIT)] and on executive functions [using the Wisconsin Card Sorting Test (WCST)]. Patients were impaired on both tests compared to controls, and male schizophrenics were impaired on the WCST compared to female schizophrenics. The pattern of results suggests that gender differences on the UPSIT are mildly accentuated in schizophrenia. The data support our previous study indicating that UPSIT performance is largely independent of the executive or attentional deficits typically associated with schizophrenia, with the exception of verbal ability. Further research with larger samples is required to test the hypothesis that there is a severely impaired subgroup of male patients with diffuse prefrontal dysfunctions.     

Scintigraphic assessment of the severity of inflammatory bowel disease using Tc 99m exametazime-labeled leukocytes

This study was designed to determine whether patients with schizophrenia and those with affective disorders display a common pattern of cognitive deficits. Cognitive performance was assessed with a neuropsychological test battery in consecutively admitted in-patients with schizophrenia (n=100) and affective disorders (n=100). The two groups of patients showed a similar pattern of cognitive deficits, especially in tests focusing on attentional capacities. The groups only differed significantly in their performance on the Wisconsin Card Sorting Test (WCST), with the schizophrenic patients performing less well. These results suggest that, with the exception of the deficit as measured by the WCST, similar cognitive impairments exist in schizophrenia and affective disorders, even at very early stages of the illness. Therefore, patients with schizophrenia and those with affective disorders cannot be qualitatively distinguished with sufficient reliability. We postulate that the cognitive deficit pattern represents a final common pathway disorder in the two groups of patients.     

Patterns of ego boundary disturbance in neurotic, borderline, and schizophrenic patients.

As part of a series of articles addressing unresolved conceptual and empirical questions regarding structural diagnosis and the borderline concept, this study examines differences in the representation of interpersonal boundaries among neurotic, borderline, and schizophrenic patients. Drawing on the contributions of Blatt and his colleagues, a Boundary Disturbance Scale was constructed by applying a developmental continuum of boundary representation to a traditional ego psychological analysis of thought disorder on the Rorschach. The results of the study support the hypothesis that severe borderline psychopathology can be conceptualized as a failure to maintain the inner-outer boundary, that schizophrenia involves a deficit in maintaining the distinction between self and others, and that meaningful developmental distinctions between diagnostic groups can be made on the basis of the Rorschach. The findings demonstrate the broad explanatory scope gained by a developmental object relations model in clarifying perplexing diagnostic and conceptual issues involving borderline phenomena on the Rorschach, specifically, (1) the representation of boundaries, (2) the cognitive disturbance involving the inner-outer boundary, and (3) the nature of the short-lived, circumscribed psychotic... (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Broadening dual modality cue utilization in chronic nonparanoid schizophrenics.

Recent evidence suggests that chronic nonparanoid schizophrenics show a narrowed range of cue utilization, especially when cues from more than 1 sensory modality are task relevant. In the present study with 20 male nonparanoid schizophrenic inpatients, it was hypothesized that this deficit can be ameliorated. All Ss were given premeasures of narrowed cue utilization on 2 dual modality tasks. Experimental Ss were then given contingent reinforcement and feedback on 2 tasks, while controls received nonreinforced practice on 1 task and no practice on the other. The major hypothesis was supported; experimental Ss improved (i.e., broadened) significantly more than controls on both tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Signal detection in vigilance tasks and behavioral attributes among offspring of schizophrenic mothers and among hyperactive children.

24 children of schizophrenic mothers, 20 children of mothers with nonpsychotic psychiatric disorders falling outside the schizophrenia spectrum, and 14 hyperactive children were examined relative to groups of individually matched comparison children and to a representatively stratified group of 67 normal children. Ss were 9–16 yrs of age. Children of schizophrenic mothers showed lower mean perceptual sensitivity (PS) than matched and stratified normal children and included an excessive number of extremely poor scorers. Neither children of mothers with nonpsychotic disorders outside the schizophrenia spectrum nor hyperactive children displayed a significant deficit in PS. Hyperactive children scored lower on a beta response criterion factor across vigilance tasks and were rated as higher on an Emotionality factor and lower on a Fearful Inhibition factor than their normal peers. The perceptual sensitivity deficit among children of schizophrenic mothers was found across motivational feedback conditions and was evident throughout the vigilance period. (3? p ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neuropsychological impairment in Tardive dyskinesia.

Tardive dyskinesia (TD) is a movement disorder secondary to neuroleptic treatment. Whether TD is associated with neurocognitive dysfunction is a controversial issue. We reviewed 31 published studies evaluating neuropsychological (NP) test results in schizophrenic patients with and without TD and found that TD was generally reported to be associated with cognitive impairment. Numerous methodological limitations, however, restrict the conclusions made about the relationship between cognition and dyskinesia. We therefore undertook a study in which 143 schizophrenic patients were evaluated on a comprehensive NP test battery. On both global and learning deficit scores, TD patients demonstrated greater impairment than did a matched comparison group. Two aspects of TD (severity and topography) were related to severity of cognitive impairment. These findings suggest that dyskinesia and cognition may share some underlying mechanism in schizophrenia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of weight intensity on discrimination thresholds of normals and schizophrenics.

20 male chronic schizophrenics, 12 chronic disturbed schizophrenics, and 20 normal controls were tested for upper difference limens from both a 40-gm (light) and 400-gm (heavy) standard weight. Weight discrimination thresholds were found to be significantly elevated as a function of severity of pathology in the schizophrenic groups and also at the lighter weight intensity. Both groups of schizophrenics showed significantly greater improvement than normals with the heavy weights. The less disturbed chronic schizophrenics were not significantly different from normals at the heavy intensity. The results support the hypothesis of a schizophrenic deficit in proprioceptive acuity and suggest that this deficit is the result of insufficient proprioceptive feedback. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Concrete operational thinking, diagnosis, and psychopathology in hospitalized schizophrenics.

Assessed the hypothesis that performance on cognitive tests would differentiate among various patient subgroups classified according to diagnosis and chronicity. 66 acute and chronic male schizophrenic inpatients were administered tests of conservation, class inclusion, and geometric drawing. Results show that acute Ss achieved significantly higher scores on 4 cognitive subtests than did chronic nonparanoids, but differences between chronic paranoids and nonparanoids were not significant. Ratings of psychopathology dimensions, especially conceptual dysfunction, discriminated significantly among Ss at 3 levels of performance on conservation tests. (16 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Context-Processing Deficits in Schizotypal Personality Disorder.

Research suggests that schizotypal personality disorder (SPD) is a part of the spectrum of schizophrenia-related illnesses. This article hypothesizes that a deficit in the representation and maintenance of context is a core cognitive disturbance in schizophrenia and that SPD individuals should demonstrate context-processing deficits. To test this hypothesis, the authors administered 3 versions of their AX-CPT task, designed to assess context processing, to 35 healthy controls and 26 individuals with DSM-IV SPD. They also administered working memory and selective attention tasks. SPD individuals displayed context representation deficits similar to those found in schizophrenia but did not show the same additional deficits in context maintenance. Context processing was strongly associated with working memory and selective attention performance in the SPD individuals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Critical interstimulus interval in delusional schizophrenics and normals.

The critical interstimulus interval, the minimum interval between presentation of a test and mask stimulus at which the mask no longer interferes with processing of the test stimulus, was calculated for 10 schizophrenics with delusional symptoms and 10 normal college students. All Ss had previous experience with the masking procedure. Each S's critical interstimulus interval was obtained 4 times in 4 separate sessions. Results indicate a larger critical interstimulus inteval for the schizophrenics. All Ss also showed less masking with practice. Results are consistent with A. J. Yates's (see record 1966-05514-001) hypothesis of a schizophrenic deficit prior to cortical levels of information processing but were inconsistent with A. J. Yates and P. Korboot's (see record 1971-06730-001) findings that slow information processing is unique to chronic nonparanoid schizophrenics. Post hoc analysis suggests the possibility of an additional schizophrenic deficit in preattentive filtering. Directions for future research are discussed. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)