Wisconsin Card Sorting Test dimensions in schizophrenia: factorial, predictive, and divergent validity

Psychometric Properties of Two Tasks in the Allen Cognitive Level Screen-Sixth Edition for Community-Dwelling People Living With Schizophrenia

IMPORTANCE

Empirical evidence is needed on the psychometric properties of the Allen Cognitive Level Screen-Sixth Edition (ACLS-6), an instrument that assesses cognitive functions and is commonly used for people living with schizophrenia.

OBJECTIVE

To examine the convergent validity, discriminative validity, and test-retest reliability of two tasks, stitching and copying, in the ACLS-6 for community-dwelling people living with schizophrenia.

DESIGN

Prospective observational study.

SETTING

Psychiatric center.

PARTICIPANTS

110 people living with schizophrenia.

OUTCOMES AND MEASURES

To examine convergent validity, we calculated correlations (Pearson's r) between the two tasks and between these two tasks and three cognitive measures. We checked for floor and ceiling effects and conducted independent t tests to evaluate discriminative validity. We calculated intraclass correlation coefficients (ICCs) to investigate test-retest reliability.

RESULTS

We found a strong correlation (r = .88) between the two tasks and moderate correlations (rs = .32-.52) between the two tasks and the three cognitive measures. No floor or ceiling effects were observed for the two tasks, and t tests showed significant differences between two participant groups with marginal and mild clinical symptoms (p < .001). The ICC values for the two tasks were .71-.74.

CONCLUSION AND RELEVANCE

The stitching and copying tasks of the ACLS-6 have good convergent validity, discriminative validity, and test-retest reliability for community-dwelling people living with schizophrenia. The copying task showed a strong correlation with the stitching task and a similar score range, so practitioners can consider using the copying task as a substitute for the stitching task. What This Article Adds: The stitching and copying tasks of the ACLS-6 have sound psychometric properties for measuring cognitive functions in community-dwelling people living with schizophrenia.

A network analysis and empirical validation of executive deficits in patients with psychosis and their healthy siblings

BACKGROUND

Psychopathological symptoms and cognitive impairment are core features of patients with psychotic disorders. Executive dysfunctions are commonly observed and typically assessed using tests like the Wisconsin Card Sorting Test (WCST). However, the structure of executive deficits remains unclear, and the underlying processes may be different. This study aimed to explore and compare the network structure of WCST measures in patients with psychosis and their unaffected siblings and to empirically validate the resulting network structure of the patients.

METHODS

The subjects were 298 patients with a DSM 5 diagnosis of a psychotic disorder and 89 of their healthy siblings. The dimensionality and network structure of the WCST were examined by means of exploratory graph analysis (EGA) and network centrality parameters.

RESULTS

The WCST network structure comprised 4 dimensions: perseveration (PER), inefficient sorting (IS), failure to maintain set (FMS) and learning (LNG). The patient and sibling groups showed a similar network structure, which was reliably estimated. PER and IS showed common and strong associations with antecedent, concurrent and outcome validators. The LNG dimension was also moderately associated with these validators, but FMS did not show significant associations.

CONCLUSIONS

Four cognitive processes underlying WCST performance were identified by the network analysis. PER, IS and LNG were associated with and shared common antecedent, concurrent and outcome validators, while FMS was not associated with external validators. These four underlying dysfunctions might help disentangle the neurofunctional basis of executive deficits in psychosis.

Age, education and gender effects on Wisconsin card sorting test: standardization, reliability and validity in healthy Argentinian adults

The Wisconsin Card Sorting Test (WCST) is a widely used neuropsychological assessment of executive functioning. The aim of this study was to provide norm values and analyze the psychometric properties of WCST in healthy Argentinian adults aged from 18 to 89 years old (N = 235). Descriptive statistics are reported as means, standard deviations and percentiles, with the effects of age, education and gender being investigated by ANOVA, and with the effect sizes being calculated. The psychometrics were studied using the WCST structure, reliability, convergent validity, and discriminant validity, and WCST norms adjusted for age and educational level are proposed. This instrument is a reliable and valid tool for the assessment of executive functions. However, as the age- and educational-related effects were demonstrated, these characteristics need to be considered before interpreting WCST scores. Regarding gender, no differences were found. Our results expand the geographical and sociocultural applicability of WCST.

Procrastination as evidence of executive functioning impairment in college students

Research addressing procrastination behavior has historically focused upon personality and situational factors to explain the nature of this problematic behavior. Although researchers have identified personality traits that are closely associated with procrastination behavior, the literature is sparse in addressing other possible explanations, particularly those related to brain functioning. Considering that procrastination is described with terms such as "poor time management," "lack of planning," and "poor judgment," amongst others, one might consider whether executive functioning systems are functioning adequately in these individuals. Individuals who demonstrate difficulties with executive functioning tend to share the same characteristics that are applied to those who procrastinate.Preliminary self-report research by Jurado and Rosselli found that undergraduates who reported higher levels of procrastination, also reported high levels of executive functioning difficulties. This research project replicated and extended these findings utilizing three common neuropsychological measures of executive functioning. The results from these measures demonstrated that individuals who showed impairment in executive functioning also reported difficulties with executive functioning and procrastination.

Cognitive abilities underlying performance on the modified card sorting test: novel and traditional scores

The Modified Card Sorting Test (MCST) is a widely used variation of the Wisconsin Card Sorting Test. It is faster to administer, less frustrating for respondents and less ambiguous in its scoring but has been criticized for its task impurity and low discriminability between control participants and clinical groups prone to executive dysfunction. This study aimed to examine the executive functions (EF) underlying traditional (number of categories completed, perseverative errors) and novel scores for the MCST, and compare their ability to differentiate between control and clinical samples. Novel and traditional MCST scores were compared between 94 control participants, 87 with bipolar disorder and 64 with major depression. The relationship between MCST scores and traditional EF tasks was examined through correlation and regression analyses. All MCST scores were associated with at least one measure of EF, the most common of which were the Trail Making or Hayling Tests. IQ predicted most scores on the MCST, save for nonperseverative errors and categorizing efficiency. Traditional and novel scores differentiated between clinical and control groups. These findings support the utility of the MCST in detecting executive dysfunction and highlight the importance of new scoring methods in increasing the specificity and interpretability of this task.

Comparing executive functioning and clinical and sociodemographic characteristics of people with schizophrenia who hold a driver's license to those who do not

BACKGROUND.

Community engagement requires driving. However, there is paucity of research focusing on the potential to drive for people with schizophrenia.

PURPOSE.

This study aimed to characterize people with schizophrenia by comparing clinical signs, executive functions (EF), and sociodemographic aspects of those holding a driver's license to those without one.

METHOD.

This cross-sectional study used convenience sampling to select 60 ambulatory individuals to participate: 31 with a driver's license and 29 without one. They completed the Wisconsin Card Sorting Test (WCST) for evaluation of EF and the Positive and Negative Syndrome Scale (PANSS) for symptoms severity evaluation. Data were analyzed using multivariate analyses of covariance and logistic regression models.

FINDINGS.

Participants with a license had less severe negative symptoms and general psychopathology and better EF and sociodemographic aspects compared to those without a license. Logistic regression revealed significant odds ratios (OR) in general psychopathology (PANSS; OR = 0.963, p = .011) and in the WCST (OR = 0.504, p = .027).

IMPLICATIONS.

This study offers occupational therapists a data-driven perspective on evaluating potential fitness to drive to enable participation in daily life and well-being of people with schizophrenia.

Neurocognitive dimensions characterising patients with first-episode psychosis

Background

Assessment of neurocognitive dysfunction in schizophrenia is hampered by the multitude of tests used in the literature.

Aims

We aimed to identify the main dimensions of an assessment battery for patients with first-episode psychosis and to estimate the relationship between dimension scores and gender, age, education, diagnosis and symptoms.

Method

Eight frequently used neuropsychological tests were used. We tested 219 patients 3 months after start of therapy or at remission, whichever occurred first.

Results

We identified five dimensions: working memory (WM); verbal learning (VL); executive function (EF); impulsivity (Im); and motor speed (MS). Significant findings were that the MS score was higher for men, and the WM and VL scores were correlated with years of education.

Conclusions

Neurocognitive function in first-episode psychosis is described by at least five independent dimensions.

Cognitive remediation for individuals with psychosis: efficacy and mechanisms of treatment effects

BACKGROUND

The popularity of cognitive remediation (CR) interventions for individuals with psychosis is in part based on the well-established link between cognition and functioning and the assumption that by targeting cognition, function can improve. While numerous trials have reported CR's efficacy, it is still not considered an evidence-based treatment. Importantly, little is known about the mechanisms through which it may affect functioning.

METHOD

In this study, we evaluated CR's proximal and distal effects, and examined potential mechanisms. A total of 75 individuals with psychotic disorders were randomized to a combination of strategy-based and drill-and-practice CR or wait-list control, with assessments of training task performance, neurocognition, functional capacity, symptoms and functioning conducted at baseline, end of the 2-month intervention, and 2-month follow-up.

RESULTS

Compared with treatment as usual, CR was associated with large post-training improvements on training tasks targeting attention, visuospatial memory, and verbal learning and memory, with persisting group differences at the 2-month follow-up. These generalized to mostly large improvements on neuropsychological measures targeting visuospatial memory, verbal learning and memory, delayed verbal memory and verbal working memory. While there were no CR-associated improvements on measures of functional capacity, symptoms, or a self-report measure of independent living skills, there was an effect on an interviewer-rated measure of functioning (Quality of Life Scale), which appeared primarily driven by the Intrapsychic Foundations subscale. Finally, for those randomized to CR, there were significant, medium-sized correlations between training task improvement, neuropsychological improvement and functioning measures.

CONCLUSIONS

This suggests a complex, multifactorial relationship between CR, and cognitive and functional change.

A Correlative Classification Study of Schizophrenic Patients with Results of Clinical Evaluation and Structural Magnetic Resonance Images

Patients with schizophrenia suffer from symptoms such as hallucination and delusion. There are currently a number of publications that discuss the treatment, diagnosis, prognosis, and damage in schizophrenia. This study utilized joint independent component analysis to process the images of GMV and WMV and incorporated the Wisconsin card sorting test (WCST) and the positive and negative syndrome scale (PANSS) to examine the correlation of obtained brain characteristics. We also used PANSS score to classify schizophrenic patients into acute and subacute cases, to analyze the brain structure differences. Finally, we used brain structure images and the error rate of the WCST as eigenvalues in support vector machine learning and classification. The results of this study showed that the frontal and temporal lobes of a normal brain are more apparent than those of a schizophrenia brain. The highest level of classification recognition reached 91.575%, indicating that the WCST error rate and characteristic changes in brain structure volume can be used to effectively distinguish schizophrenia and normal brains. Similarly, this result confirmed that the WCST and brain structure volume are correlated with the differences between schizophrenia and normal participants.

Intrinsic motivation as a mediator between metacognition deficits and impaired functioning in psychosis

OBJECTIVE

Poor functioning has long been observed in individuals with psychosis. Recent studies have identified metacognition - one's ability to form complex ideas about oneself and others and to use that information to respond to psychological and social challenges-as being an important determinant of functioning. However, the exact process by which deficits in metacognition lead to impaired functioning remains unclear. This study first examined whether low intrinsic motivation, or the tendency to pursue novel experiences and to engage in self-improvement, mediates the relationship between deficits in metacognition and impaired functioning. We then examined whether intrinsic motivation significantly mediated the relationship when controlling for age, education, symptoms, executive functioning, and social cognition.

DESIGN

Mediation models were examined in a cross-sectional data set.

METHODS

One hundred and seventy-five individuals with a psychotic disorder completed interview-based measures of metacognition, intrinsic motivation, symptoms, and functioning and performance-based measures of executive functioning and social cognition.

RESULTS

Analyses revealed that intrinsic motivation mediated the relationship between metacognition deficits and impaired functioning (95% CI of indirect effect [0.12-0.43]), even after controlling for the aforesaid variables (95% CI of indirect effect [0.04-0.29]).

CONCLUSIONS

Results suggest that intrinsic motivation may be a mechanism that underlies the link between deficits in metacognition and impaired functioning and indicate that metacognition and intrinsic motivation may be important treatment targets to improve functioning in individuals with psychosis.

PRACTITIONER POINTS

The findings of this study suggest that deficits in metacognition may indirectly lead to impaired functioning through their effect on intrinsic motivation in individuals with psychosis. Psychological treatments that target deficits in both metacognition and intrinsic motivation may help to alleviate impaired functioning in individuals with psychosis.

LIMITATIONS

The cross-sectional design of this study is a limitation, and additional longitudinal studies are needed to confirm the direction of the findings and rule out rival hypotheses. Generalization of the findings may be limited by the sample composition. It may be that different relationships exist between metacognition, intrinsic motivation, and functioning in those with early psychosis or among those in an acute phase or who decline treatment.

Cognitive impairment in schizophrenia

Cognitive functioning is moderately to severely impaired in patients with schizophrenia. This impairment is the prime driver of the significant disabilities in occupational, social, and economic functioning in patients with schizophrenia and an important treatment target. The profile of deficits in schizophrenia includes many of the most important aspects of human cognition: attention, memory, reasoning, and processing speed. While various efforts are under way to identify specific aspects of neurocognition that may lie closest to the neurobiological etiology and pathophysiology of the illness, and may provide relevant convergence with animal models of cognition, standard neuropsychological measures continue to demonstrate the greatest sensitivity to functionally relevant cognitive impairment.The effects of antipsychotic medications on cognition in schizophrenia and first-episode psychosis appear to be minimal. Important work on the effects of add-on pharmacologic treatments is ongoing. Very few of the studies completed to date have had sufficient statistical power to generate firm conclusions; recent studies examining novel add-on treatments have produced some encouraging findings. Cognitive remediation programs have generated considerable interest as these methods are far less costly than pharmacologic treatment and are likely to be safer. A growing consensus suggests that these interventions produce modest gains for patients with schizophrenia, but the efficacy of the various methods used has not been empirically investigated.

Executive function in deficit schizophrenia: what do the dimensions of the Wisconsin Card Sorting Test tell us?

Neuropsychological characterization of the schizophrenia deficit syndrome is an unresolved issue. The initial assumption was that patients with deficit syndrome show more definitive impairments on tests sensitive for frontal and parietal functions compared with nondeficit patients,but recent studies failed to confirm this assumption. The fundamental question is whether a more refined delineation of executive dysfunctions is able to yield differences between deficit and nondeficit patients. To investigate this question, we implemented a factor analytic approach to explore potential differences between deficit and nondeficit patients using the Wisconsin Card Sorting Test (WCST). Our paper presents an exploratory factor analysis of the WCST on schizophrenia patients and healthy samples, and a comparison among deficit, non-deficit patients with schizophrenia and control samples using the identified factors. A total of 154 patients with schizophrenia fulfilling the criteria for the deficit syndrome, 121 nondeficit patients, and 130 healthy controls were compared. Factor analysis of the WCST variables using the principal component method resulted in a two-factor solution. Comparison of the diagnostic groups on each of the factors revealed that deficit schizophrenia patients suffer from a more severe degree of impairment on the 'General executive function' factor than nondeficit schizophrenia patients. To our knowledge this is the first study that compared patients with the deficit and non-deficit forms of schizophrenia using WCST factor analytic techniques. Our results provide an insight into the cognitive profile of schizophrenia patients with regard to WCST, which could serve as a framework for future clinical and research endeavors.

Longitudinal alterations of executive function in non-psychotic adolescents at familial risk for schizophrenia

Genetic diathesis to schizophrenia may involve alterations of adolescent neurodevelopment manifesting as cognitive deficits. Brain regions mediating executive function (fronto-striatal circuits) develop during adolescence while those supporting elementary aspects of attention (e.g. sustained focused attention) have a more protracted maturation beginning in childhood. We hence predicted that adolescents at risk for schizophrenia would show a failure of normal maturation of executive function. We prospectively assessed 18 offspring and 6 siblings of schizophrenia patients (HR) and 28 healthy controls at baseline, year-1 and year-2 follow-up using the Continuous Performance Test [visual-d'] and Wisconsin Card Sort Test (WCST). Perseverative errors on the WCST in HR remained stable but decreased in controls over the follow-up (study-group by assessment-time interaction, p=0.01, controlling for IQ). No significant study-group by assessment-time interactions were seen for sustained attentional performance. HR may not improve while healthy subjects progressively improve on executive function during adolescence and early adulthood. Our results suggest an altered maturational trajectory of executive function during adolescence in individuals at familial risk for schizophrenia.

Neurocognition, social cognition, perceived social discomfort, and vocational outcomes in schizophrenia

Social cognition has been suggested to be an important mediating variable in the relationship between neurocognition and functional outcome. The present study tested this model in relation to work rehabilitation outcome and added self-reported social discomfort as a possible mediator. One hundred fifty-one participants with schizophrenia or schizoaffective disorder participated in a 26-week work therapy program. Neurocognition was constructed as a latent construct comprised of selected variables from our intake test battery representing executive functioning, verbal memory, attention and working memory, processing speed, and thought disorder. Social cognition at intake was the other latent construct comprised of variables representing affect recognition, theory of mind, self-reported egocentricity, and ratings of rapport. The 2 latent constructs received support from confirmatory factor analysis. Social discomfort on the job was based on their self-report on a weekly questionnaire. In addition, we constructed a composite rehabilitation outcome that was based on how many hours they worked, how well they worked, and how complex was the job that they were doing. Path analysis showed direct effects of neurocognition on rehabilitation outcome and indirect effects mediated by social cognition and social discomfort. This model proved to be a good fit to the data and far superior to another model where only social cognition was the mediating variable between neurocognition and rehabilitation outcome. Findings suggest that neurocognition affects social cognition and that poorer social cognition leads to social discomfort on the job, which in turn leads to poorer rehabilitation outcomes. Implications for rehabilitation interventions are discussed.

Performance on the Modified Card Sorting Test and its relation to psychopathology in adolescents and young adults with 22q11.2 deletion syndrome

BACKGROUND

Approximately one-third of individuals with 22q11.2 deletion syndrome (22q11DS), a common genetic disorder highly associated with intellectual disabilities, may develop schizophrenia, likely preceded by a mild to moderate cognitive decline.

METHODS

We examined adolescents and young adults with 22q11DS for the presence of executive function deficits using a modified version of the Wisconsin Card Sorting Test (MCST) and assessed whether specific performances were associated with concurrent schizophrenia-prodrome symptoms. We also examined possible relationships between MCST performance and broader indices of psychopathology, including self-reported internalising and externalising behavioural symptoms.

RESULTS

Participants with 22q11DS scored significantly below age-matched controls on seven out of nine MCST measures, and poorer MCST performance was associated with increased positive prodromal and internalising behavioural symptoms.

CONCLUSIONS

The schizophrenia-prodrome in 22q11DS involves executive dysfunction, and longitudinal investigation is necessary to examine if specific executive function impairments precedes or co-occurs with the emergence of behavioural psychopathology.

Neurocognitive enhancement therapy with vocational services: work outcomes at two-year follow-up

Neurocognitive enhancement therapy (NET) is a remediation program for the persistent and function-limiting cognitive impairments of schizophrenia. In a previous study in veterans, NET improved work therapy outcomes as well as executive function and working memory. The present study aimed to determine whether NET could enhance functional outcomes among schizophrenia and schizoaffective patients in a community mental health center receiving community-based vocational services.

METHOD

Patients (N=72) participated in a hybrid transitional and supported employment program (VOC) and were randomized to either NET+VOC or VOC only. NET+VOC included computer-based cognitive training, work feedback and a social information information-processing group. VOC only also included two weekly support groups. Active intervention was 12 months with 12 month follow-up. Follow-up rate was 100%.

RESULTS

NET+VOC patients worked significantly more hours during the 12 month follow-up period, reached a significantly higher cumulative rate of competitive employment by the sixth quarter, and maintained significantly higher rates of employment.

CONCLUSION

NET training improved vocational outcomes, suggesting the value of combining cognitive remediation with other rehabilitation methods to enhance functional outcomes.

Construct Validity of the Wisconsin Card Sorting Test-64 in Patients with Stroke

This study examined the factor structure and contrasted-group validity of the Wisconsin Card Sorting Test-64 (WCST-64) in a stroke sample (n = 112). Confirmatory factor analyses were used to compare five different models suggested by prior factor analyses. The results indicated that the WCST-64 was best represented by a three-dimensional model comprising response inflexibility (factor 1), ineffective hypothesis-testing strategy (factor 2), and set maintenance (factor 3). A significant overall multivariate effect for group (F = 2.87, df = 18,495.46, p <.001) was found in a multivariate analysis of covariance with WCST scores as dependent variables and four different groups (three stroke subgroups with different levels of cognitive function and a normal control group) as independent variable, after controlling for gender. The results of discriminant analysis supported the use of the WCST-64 in stroke patients with cognitive impairment.

Wisconsin Card Sorting Test: factor structure and relationship to productivity and supervision needs following severe traumatic brain injury

PRIMARY OBJECTIVE

The Wisconsin Card Sorting Test (WCST) has been demonstrated to have a relatively stable factor structure in traumatic brain injury (TBI) samples. What is less clear is whether the scores derived from WCST factors are related to functional outcomes. The purpose of the current study was to replicate the WCST factor structure in a sample with severe TBI, and to evaluate the relationship between the factor scores and outcome.

RESEARCH DESIGN

Retrospective correlational study.

METHODS AND PROCEDURES

Participants (n=143) who had suffered severe TBI were administered a battery of neuropsychological tests including the WCST within one month of admission to a brain injury rehabilitation program. In addition, participants were administered supervision (Supervision Rating Scale; SRS) and productivity measures (Community Integration Questionnaire- Productivity subscale; CIQ-P) at admission and following discharge.

EXPERIMENTAL INTERVENTION

None.

MAIN OUTCOMES AND RESULTS

For individuals who were more than one year post injury, more failure to maintain set errors were associated with better occupational outcomes, while more nonperseverative errors were associated with increased supervision needs.

CONCLUSIONS

The WCST factor scales are related to functional outcomes in severe TBI. Specifically, the inability to establish a series of correct responses is associated with poorer outcome.

The frontal hypothesis of cognitive aging: factor structure and age effects on four frontal tests among healthy individuals

With 101 healthy aging adult participants, the authors investigated whether executive functions are a unitary concept. The authors established the factor structure of the Wisconsin Card Sorting Test (WCST; E. A. Berg, 1948), the Stroop color and word test (C. J. Golden, 1978), verbal fluency using the Controlled Oral Word Association Test (COWAT; Benton, 1967), and the Digits Backwards subtest of the Wechsler Adult Intelligence Scale-Revised (WAIS-R; D. Wechsler, 1981). The authors also evaluated the extent to which age and other demographic variables predicted common underlying properties of these frontal tests. Results revealed an age-related decline in executive abilities differentially reflected by the selected tasks. These data suggest caution using the COWAT to evaluate executive abilities in older people. The authors interpret findings to support the unitary view of executive abilities and the executive decline proposed by the frontal hypothesis.

Integrated versus sealed-over recovery in schizophrenia: BORRTI and executive function

Ego functioning of 222 outpatients with a diagnosis of schizophrenia or schizoaffective disorder was evaluated using the Bell Object Relations and Reality Testing Inventory (BORRTI). Sixty-one of these had BORRTI profiles identified as sealed-over recovery style, and 36 had profiles interpreted as integrated recovery style. Groups were compared on demographic characteristics, symptom profiles, and the Wisconsin Card Sorting Test, a performance measure of executive function. Groups had comparably low levels of positive symptoms, but the integrated recovery group had higher scores on the BORRTI uncertainty of perception scale. The integrated recovery group had significantly fewer minority patients, higher IQ, and higher levels of emotional discomfort. The sealed-over recovery group had higher levels of cognitive disorganization. When differences in ethnicity and IQ were controlled for, the integrated recovery group had better executive functioning. Wisconsin Card Sorting Test categories completed emerged as the significant predictor in a logistic regression, explaining 19% of the variance. These findings support the discriminant validity of these two recovery styles and reveal the importance of executive function in a recovery style that allows for investment in relationships, affect tolerance, and acknowledgment of symptoms.

Do schizophrenia patients make more perseverative than non-perseverative errors on the Wisconsin Card Sorting Test? A meta-analytic study

The Wisconsin Card Sorting Test (WCST) is widely used to explore executive functions in patients with schizophrenia. Among other findings, a higher number of perseverative errors has been suggested to implicate a deficit in task switching and inhibitory functions in schizophrenia. Many studies of patients with schizophrenia have focused on perseverative errors as the primary performance index in the WCST. However, do schizophrenia patients characteristically make more perseverative than non-perseverative errors compared with healthy controls? We reviewed the literature where schizophrenia patients were engaged in the WCST irrespective of the primary goal of the study. The results showed that while both schizophrenia patients and healthy participants made more perseverative than non-perseverative errors, the contrast between perseverative and non-perseverative errors is higher in schizophrenia patients only at a marginal level of significance. This result suggests that schizophrenia patients do make a comparable number of non-perseverative errors and cautions against simplistic interpretation of poor performance of schizophrenia patients in WCST as entirely resulting from impairment in set-shifting or inhibitory functions.

Initial and final work performance in schizophrenia: cognitive and symptom predictors

Studies have shown that cognitive functioning may limit the rate, tenure, and type of work performed by people with schizophrenia. The present study tested the hypothesis that cognitive abilities needed for initial improvement in work performance would differ from those needed in later vocational development. Ninety-six outpatients with schizophrenia or schizoaffective disorder who participated in a work rehabilitation program were administered neuropsychological testing at intake. Their work performance was evaluated biweekly for 26 weeks. Cognitive test variables were entered into regressions predicting the slope of individual performance curves from weeks 1 to 13 and 13 to 26. Neuropsychological variables accounted for 28% of the variance in slope during the initial period. The strongest predictor was a Continuous Performance Task variable that measures inattentiveness. Other important variables were measures of idiosyncratic thinking, cognitive flexibility, and verbal memory. Neuropsychological variables accounted for 19% of the variance in the slope during the final period. The strongest predictor was verbal learning, while measures of cognitive impulsivity and psychomotor functioning were also significant contributors. There was no relationship between work performance and symptoms for weeks 1 to 13 or 13 to 26. These findings suggest that while attention is more important for initial success, verbal memory becomes more important for sustained improvement. Remediating or accommodating such deficits in a time-sensitive fashion may be a necessary feature for successful rehabilitation.

Wisconsin Card Sorting deficits in the offspring of schizophrenics in the New York High-Risk Project

It has been suggested that performance on the Wisconsin Card Sorting Test (WCST) may be an indicator of vulnerability to schizophrenia. WCST deficits have been demonstrated in schizophrenic patients and their relatives, but not as yet in their offspring. This study aimed to further establish the indicator potential of WCST deficits by analyzing data collected as part of the New York High-Risk Project (NYHRP), a longitudinal study of attention, cognition and clinical functioning in the offspring of schizophrenic (HRSz, n=73), affective disordered (HRAff, n=61) and normal comparison (NC, n=120) parents. Parental Research Diagnostic Criteria diagnoses were established by semi-structured interview (SADS-L). WCST testing was carried out when offspring were in their mid-20s. HRSz subjects performed significantly more poorly on the WCST than HRAff and NC subjects. High-risk subjects who developed psychotic symptoms prior to or shortly after testing did not differ significantly from HRSz subjects who did not become ill. Thus, WCST performance in the offspring of schizophrenics resembles that of schizophrenic patients and may distinguish HRSz from offspring at risk for nonschizophrenic illness. WCST deficits may be a specific familial indicator of vulnerability, but appear not to distinguish between those subjects at risk for schizophrenia who do or do not become ill.

Memory and executive function impairments in deficit syndrome schizophrenia

The relationship between deficit syndrome schizophrenia, as determined by the Schedule for the Deficit Syndrome, and impairments in memory and executive function was investigated by administering the Wisconsin Card Sorting Test, the Wechsler Adult Intelligence Test, and the Wechsler Memory Scales to outpatients with deficit (n=33) and non-deficit (n=57) syndrome. A factor analysis of test variables revealed three factors: executive functioning; simple verbal memory; and semantic verbal memory. Results indicated that the deficit group performed significantly worse on the executive functioning factor, but not on either of the verbal memory factors. These findings support the hypothesis that deficit syndrome schizophrenia represents a specific cognitive impairment in executive processing and not necessarily graver global cognitive impairment.

Object relations and reality testing in early- and late-onset schizophrenia

One hundred fifty-seven U.S. military veterans with schizophrenia were divided into early-onset (i.e., onset at age 20 or before, n = 36) and late-onset (i.e., onset after age 30, n = 28) groups and completed the Bell Object Relations and Reality Testing Inventory (BORRTI), the Positive and Negative Syndrome Scale, and several representative neuropsychological instruments. Participants were compared on background characteristics and test measures. The early-onset group demonstrated significantly more object-relations and reality-testing deficits than the late-onset group. In contrast, no significant group differences were found on symptom or neuropsychological variables. An a posteriori three-group analysis that included the middle age of onset group (i.e., ages 21 to 30) found that the middle group had mean values that fell between early- and late-onset groups on most variables. No distinct patterns of BORRTI subscale scores distinguished the middle group. The finding that object-relations and reality-testing deficits are more pronounced in early-onset schizophrenia has implications for the treatment and rehabilitation of schizophrenia.

Working memory and Wisconsin Card Sorting Test performance in schizotypic individuals: a replication and extension

The present study examined spatial working memory and Wisconsin Card Sorting Test (WCST) performance in psychosis-prone individuals, either those with extremely high scores on the Social Anhedonia Scale (SocAnh; n = 49) or deviant scores on the Perceptual Aberration-Magical Ideation Scales (Per-Mag; n = 66). Sixty-three individuals with normal scores on the Chapman Psychosis-Proneness Scales served as control subjects. In order to evaluate working memory performance, participants were administered three tasks, namely, sensorimotor, degraded stimulus, and delayed-response tasks. Although the SocAnh and Per-Mag groups displayed poorer performance than control subjects on the working memory task, they did not differ significantly from each other. The SocAnh group exhibited slower reaction times on the working memory task compared to the control group. The groups did not differ in their performance on sensorimotor or degraded stimulus control tasks. Both psychosis-prone groups differed significantly from control subjects in terms of their WCST performance. Working memory performance was inversely associated with the number of perseverative errors (r = -0.17) and the number of trials to complete the first category on the WCST (r= -0.15). These findings extend the literature by indicating that some psychosis-prone individuals with social-interpersonal schizotypal deficits also display subtle spatial working memory impairments.

Wisconsin Card Sorting Test deficits in schizotypic individuals

The present study investigates executive functioning in schizotypic college students and control subjects using the Wisconsin Card Sorting Test (WCST). Inhibitory control and working memory, two aspects of executive functioning, were examined in deviantly high scorers on the Perceptual Aberration and Magical Ideation Scales (n=97), high scorers on the revised Social Anhedonia Scale (n=58), and in control subjects (n=104). The schizotypic groups displayed significantly more perseverative errors and achieved fewer categories than the control group. The two schizotypic groups did not differ from each other. We identified a subset of schizotypic individuals who also produced clinically deviant WCST profiles. The findings support the hypothesis that executive function deficits may precede the onset of schizophrenia and related illnesses.