Wisconsin Card Sorting Test performance in schizophrenia: the role of working memory

Schizophrenia typically results in reduced performance on the Wisconsin Card Sorting Test (WCST). In the current study, we used a variety of approaches to examine the role of working memory (WM) in this deficit. One approach was to examine patterns of perseverative and non-perseverative errors. A second approach involved the comparison of the standard WCST to a modified version that used visual cues to reduce demands on WM. A third approach was to quantify the impact of WM demands on performance on a trial by trial basis. Consistent with theories of WM, the schizophrenia group showed increases in both perseverative and non-perseverative errors and differences between individuals with schizophrenia and controls were largest when WM demands were high. The visual cues helped the schizophrenia group overcome the high WM demands of the test, although they did not reduce the impairment in terms of standard scoring procedures. All impairments disappeared, however, after controlling for group differences on a measure of the speed of encoding information in WM. The pattern of results supports the conclusion that WM impairment contributes to poor performance on the WCST in individuals with schizophrenia, with additional evidence that this impairment results from generalized slowing of information processing.     

Wisconsin Card Sorting Test performance in schizophrenia: remediation of a stubborn deficit.

OBJECTIVE: Schizophrenic patients typically perform poorly on the Wisconsin Card Sorting Test, which is a putative index of prefrontal functioning. The authors attempted to remediate the deficits of schizophrenic patients on this measure by giving detailed instructions and monetary reinforcement. METHOD: Forty-six inpatients with chronic schizophrenia and 20 control subjects with other psychiatric illnesses were given the Wisconsin Card Sorting Test under four conditions that varied in monetary reinforcement and level of instructions. The schizophrenic patients were given the Brief Psychiatric Rating Scale (BPRS) and three information processing measures (the Continuous Performance Test, Span of Apprehension, and Pin Test). RESULTS: Schizophrenic patients performed worse than psychiatric control subjects across most conditions. Monetary reinforcement had little effect on performance, but detailed instructions significantly improved the scores for both groups. When instructions were withdrawn and monetary reinforcement was maintained, both groups continued to show improved performance over baseline. Symptoms were not significantly associated with Wisconsin Card Sorting Test performance. One measure (the Pin Test) correlated significantly with performance on the Wisconsin Card Sorting Test. CONCLUSIONS: The results suggest the importance of combining motivational with instructional factors for training psychiatric patients in problem solving.     

Wisconsin Card Sorting Test performance in children with developmental coordination disorder

The primary purpose of this study was to investigate and compare the executive functions measured by the Wisconsin Card Sorting Test (WCST) between children with developmental coordination disorder (DCD) and age-matched normal controls. A second purpose was to examine the relations between executive functions and school functions in DCD children. Seventy-one children with DCD and 70 children without motor problems were recruited from 14 public schools. Executive functions and school functions were assessed using the WCST, and the School Function Assessment - Chinese Version (SFA-C) respectively. Univariate analyses demonstrated significant between-group differences in five WCST measures. The logistic regression analysis showed differences between two groups on eight SFA-C subscales, and significant correlation between items measured on WCST and SFA-C was also found. The result of the study provides further evidence of impaired sub-domains of executive functions (i.e., mental shifting, flexibility) in children with DCD. The finding also adds to recent investigations into the relationship between executive functions and school functions in DCD. Implications for rehabilitation professionals and recommendations for further research are discussed.     

Impaired Wisconsin Card Sorting Test performance in first-episode severe depression

An important issue in the practice of clinical neuropsychology is to define the degree to which impaired executive functions associated with severe depression are a result of organic dysfunction or of only current depressive experience, reflecting clinical state. Twenty-eight patients with psychotic depression, 29 with nonpsychotic depression and 30 healthy controls, matched for age and education were tested on WCST, WAIS-R, and the Rorschach according to the Comprehensive System, providing indices of depression (DEPI) and coping deficit (CDI). Patients were impaired in WCST performance. The stepwise regression for WCST scores yielded two significant predictor variables: the DEPI and Digit Symbol as a measure of complex attention and response speed. Within the groups, Picture Completion in patients with nonpsychotic depression and the CDI in patients with psychotic depression emerged as the significant predictors of WCST scores. Patients with severe major depressive disorder have profound executive impairments as assessed by the WCST at early stages of the illness. Intense emotional distress and psychomotor retardation seem to contribute to impaired performance. The depression groups revealed different response patterns, reflecting more severe deterioration and signs of possible organic dysfunction in patients with psychotic depression.     

Wisconsin Card Sorting Test performance before and after temporal lobectomy

Wisconsin Card Sorting Test (WCST) performance was studied before and after patients underwent right (n = 34) or left (n = 34) temporal lobectomy. Patients had hemisphere language dominance judged on intracarotid amobarbital testing and were free of space-occupying lesional pathology by magnetic resonance imaging (MRI). Right and left lobectomy patients did not differ before or after surgery on WCST parameters: categories completed, perseverative errors, total correct responses, total errors, nonperseverative errors, and perseverative responses. There was no relationship between WCST performance and MRI-determined hippocampal volumes or age of recurrent seizure onset. These findings are contrary to previous reports, suggesting the presence of laterality effects on preoperative WCST performance, relationships between WCST performance and age of seizure onset, and association of WCST performance and degree of mesial temporal sclerosis. Data from this study are consistent with a report on a larger group of temporal lobectomy patients, which found no laterality effect on WCST performance. The WCST seems to be of no value when attempting to lateralize seizure onset in nonlesional temporal lobe epilepsy.     

Wisconsin Card Sorting Test: an indicator of vulnerability to schizophrenia?

The Wisconsin Card Sorting Test (WCST) is a neuropsychological test, hypothesized to be an indicator of dorsolateral prefrontal cortex (DLPFC) functioning. The performance of schizophrenic patients in our sample (off medication) was worse than the performance of healthy controls in all variables of the WCST, including perseverative responses (PR) as well as non-perseverative responses (NPR). The rate of perseverative and non-perseverative responses was neither a function of the severity of the illness (measured by SANS/SAPS scales) nor the duration of the disease. Healthy siblings of schizophrenic probands revealed more perseverative responses than healthy controls, but did not show any difference with respect to the non-perseverative responses. This finding suggests that the difficulty to shift a cognitive set, reflected by the frequency of perseverative responses, is in favor of the WCST as a vulnerability marker for schizophrenia, whereas non-perseverative responses presumably indicate a state, but not a trait marker of the disease. However, the usefulness of this indicator may be limited by its association with age, which is worthy of being studied in closer detail.     

A comparison of remediation techniques on the Wisconsin Card Sorting Test in schizophrenia

A wealth of evidence has revealed that deficits on a commonly used measure of executive-function, the Wisconsin Card Sorting Test (WCST), can be improved through a variety of methods of instruction in patients with schizophrenia. Relatively little is known however, which of these remediation methods produce strongest and most durable effects and whether these effects generalize to other, untrained executive-function measures. Two of the most commonly studied methods for remediation on the WCST, step-by-step didactic instruction on the task and utilization of self-monitoring strategies, have both been shown to improve WCST performance, yet have never been directly compared. Thirty-four participants with schizophrenia were randomly assigned to one of three experimental conditions: Condition A consisted of didactic training which incorporated a detailed account of changing sorting principles throughout the test; Condition B consisted of a self-monitoring strategy that required that participants verbalize their strategies out loud after each card sort; Condition C was a non-trained control group that received the same outcome assessments as the two training groups at identical time intervals without intervening training. Patients were assessed with the WCST and two other executive-function tests immediately prior to training, immediately after training and at a 1-month follow-up. Results revealed: (1) participants assigned to the didactic and self-monitoring conditions made significant gains on the WCST relative to a no-intervention control condition; (2) the effects of self-monitoring, but not didactic training, were evident at a one-month follow-up; and (3) only participants assigned to the self-monitoring condition showed generalization to a second, non-trained measure of executive-function. The significance of these results for implementation of strategies for comprehensive and sustained programs of remediation are discussed.     

Performance of patients with schizophrenia on the Wisconsin Card Sorting Test (WCST)

OBJECTIVE: To directly compare the performance of patients with schizophrenia and control subjects on the Wisconsin Card Sorting Test (WCST). Specifically, we sought to verify if there are significant differences on the "classical" WCST measurements (perseverative errors and number of categories), as well as on more rarely reported scores, and assess the extent to which patients with schizophrenia can improve their performance with card-by-card instructions and continuous verbal reinforcement. DESIGN: Prospective cross-sectional study. SETTING: Psychiatry department in a university-affiliated hospital. PARTICIPANTS: 30 patients with schizophrenia, diagnosed according to DSM-IV criteria, and 30 control subjects, matched to patients according to age and education. INTERVENTION: The WCST was administered according to the criteria of Heaton, and a subgroup of the patients with schizophrenia was given a retest after an explanation of the WCST and verbal reinforcements. RESULTS: Patients with schizophrenia succeeded on fewer categories (t = 23.3, p < 0.001), committed more perseverative errors (t = 15.6, p < 0.001), made more perseverative responses (t = 14.6, p < 0.001), needed more trials to succeed at the first category (t = 9.2, p < 0.003) and gave significantly lower conceptual level responses (t = 14.1, p < 0.001) than the controls. However, on retest, patients with schizophrenia committed significantly fewer perseverative errors (t = 5.1, p < 0.001) and showed higher conceptual level responses (t = -3.45, p < 0.003). CONCLUSION: Consistent with a hypothesis of frontal dysfunction in schizophrenia, patients with schizophrenia tend to show a perseverative deficit; however, some are able to partially overcome this deficit when given verbal reinforcement.     

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.     

Wisconsin Card Sorting Test performance in patients with complex partial seizures of temporal-lobe origin

Wisconsin Card Sorting Test (WCST) performance was investigated in patients with complex partial seizures (CPS) of dominant (n = 16) or nondominant (n = 19) temporal-lobe origin as well as in an epilepsy control group (n = 6) which consisted largely of patients with primary generalized epilepsies. Fifty seven percent of the CPS group (39% of dominant and 74% of nondominant temporal-lobe patients) performed in a manner suggestive of frontal-lobe pathology compared to 17% of the epilepsy controls. There were no differences among the groups in the number of categories achieved, but there were substantial qualitative differences in problem-solving efficiency. Nondominant temporal patients manifested more total errors and perseverative errors relative to both dominant temporal and epilepsy controls, and more perseverative responses relative to epilepsy controls. Dominant temporal-lobe patients showed more perseverative errors than epilepsy controls. Finally, a consecutive series of patients who underwent partial temporal-lobe resection were examined 6 months post-surgically and they were found to manifest significantly fewer perseverative responses. The possible reasons for "frontal-like" performance in CPS patients with documented temporal-lobe pathology are discussed and a specific hypothesis is suggested.     

Cross-cultural comparisons on Wisconsin Card Sorting Test performance in euthymic patients with bipolar disorder

We compared executive dysfunction with the Wisconsin Card Sorting Test (WCST) among distinct national and ethnic patients with bipolar disorder in euthymia. Bipolar patients, aged 16-45 years, from the United States (n = 25) and Taiwan (n = 30) did not differ significantly on any measure. The WCST score for number Failure to Maintain Set was significantly positively correlated with residual affective symptoms in Taiwanese and US patients. Selective executive dysfunction in euthymia is inherent to bipolar disorder. Euthymic bipolar patients of various ethnic groups may exhibit similar executive dysfunction.     

Executive performance on the Wisconsin Card Sorting Test in mesial temporal lobe epilepsy

Executive dysfunction assessed by the Wisconsin Card Sorting Test has been observed in patients with mesial temporal lobe epilepsy (TLE); however, the mechanism of executive impairment is unclear. We therefore investigated the potential contribution of the hippocampus toward executive dysfunction in 85 mesial TLE patients, and in a control group of 34 patients with neocortical TLE. Standardized regression-based methodology was used for correcting test-retest bias. We found that 56% of mesial TLE patients had impaired sorting performance, with 30% showing severe impairment. A lower full-scale intelligence quotient, older age, longer duration, and preoperative use of topiramate were significantly correlated with poorer preoperative sorting abilities. However, neither these variables nor postoperative discontinuation/reduction of topiramate were related to postoperative changes in sorting abilities. Only preoperative sorting abilities were negatively correlated with postoperative changes in executive performance. That is, patients with better preoperative executive ability showed greater postoperative deterioration in executive function, whereas those with poorer preoperative sorting ability had greater improvement in executive function after mesial temporal resection. There were no differences in card sorting ability between the mesial and neocortical TLE groups. In conclusion, our results suggest that impairment of card sorting performance in the mesial TLE group cannot be explained only by hippocampal dysfunction, but that other processes (possibly epileptic discharges propagated to the extratemporal area) must play a predominant role.     

Prefrontal cortical dysfunction in depression determined by Wisconsin Card Sorting Test performance.

OBJECTIVE: Neuroimaging studies have demonstrated reduced prefrontal cortical blood flow and metabolism in depression, but the neurobehavioral significance of these observations is not yet established. METHOD: The Wisconsin Card Sorting Test, a widely used neuropsychological index of prefrontal cortical function, was administered to 79 patients with major depression who had been unmedicated for at least 28 days, to 47 patients with schizophrenia who had never received antipsychotic medication, and to 61 healthy comparison subjects. RESULTS: Depressed patients demonstrated significant deficits on multiple Wisconsin Card Sorting Test measures compared with healthy individuals. These deficits were correlated with the severity of depression and were less severe than those demonstrated by patients with schizophrenia. CONCLUSIONS: These results provide neuropsychological evidence for significant prefrontal cortical dysfunction in depression.     

Relationship of good and poor Wisconsin Card Sorting Test performance to illness duration in schizophrenia: a cross-sectional analysis

The authors investigated whether schizophrenic patients with good and poor performance on the Wisconsin Card Sorting Test (WCST) showed cognitive modifications related to duration of illness. Of the 154 patients evaluated with the WCST, 56 subjects had normal or mildly impaired performance and 98 showed impairment on the basis of the number of categories achieved (0-3 categories = poor performance). These subsamples were then cross-sectionally divided into three subsamples depending on length of illness (< 5 years, 6-10 years, > 10 years). The inclusion of 69 healthy controls allowed the effect of age to be taken into account. The schizophrenic group as a whole and the group of poor performers did not show differences in any of the WCST indices related to length of illness. Good performers instead showed improvement on the intermediate length-of-illness group (6-10 years of illness), and then decline in the third one (> 10 years). Good performers only showed a positive significant correlation between age, age at onset, educational level and successful WCST performance. Results for the poor performers support the hypothesis of no progressive 'deteriorating' course of schizophrenia, while good performers show an unstable pattern of cognitive functions. These data support the hypothesis that cognitive deficits associated with schizophrenia cannot be considered a unitary trait, but emerge along different hypothetical trajectories.     

An association study of dopamine receptors polymorphisms and the Wisconsin Card Sorting Test in schizophrenia

Summary. Dopamine (DA), an important neurotransmitter in prefrontal cortex (PFC), is involved in the pathogenesis of schizophrenia. The aim of the study was to test an association between common polymorphism of genes for DA receptors DRD1, DRD2, DRD3, DRD4, and performance on the Wisconsin Card Sorting Test (WCST), measuring various functions of PFC, in 138 schizophrenic patients. Patients with G/G genotype of DRD1 tended to obtain worse results in all domains of WCST compared to patients with remaining genotypes, particularly for number of completed corrected categories, and trials to set the first category. A relationship was also found in female patients between DRD2 polymorphism and number of perseverative errors, while no association between WCST results and DRD3 or DRD4 polymorphism was observed in patients studied. The results may suggest an association between DRD1 gene polymorphism and performance on PFC test in schizophrenia. Also, the gender-dependent role of DRD2 in this process may be presumed.     

Attentional characteristics of schizophrenia patients differing in learning proficiency on the Wisconsin Card Sorting Test

The Wisconsin Card Sorting Test (WCST), a test of concept formation, was given to 49 schizophrenia inpatients in three blocks of 64 cards each with the second block comprising special instructions and trial-by-trial feedback. With the help of a psychometric algorithm based on linear regression analysis, the patients were classified according to their response to these specific interventions. Results yielded 15 high scorers, 23 learners, and 11 nonlearners. This a priori classification was confirmed by cluster analysis. Next, these groups were further analyzed with the Degraded Stimulus Continuous Performance Test (DS-CPT), a test of target discrimination, and the Test of Attentional Style (TAS), which assesses habitual, subjectively experienced attentional problems. A significant difference between high scorers and nonlearners was found for discriminative sensitivity (d'), with the learners achieving intermediate scores. Results for only the DS-CPT response criterion (beta) and a TAS subscale (Distractibility) tended to be significant. Discriminant analysis also revealed that d' is the most powerful variable for discriminating among the subgroups. The article also addresses baseline versus dynamic assessment, specific rehabilitation needs in subgroups of schizophrenia patients different in learner status, and the neurocognitive characteristics of the subgroups.     

以阴、阳性症状为主的精神分裂症患者威斯康星卡片分类测验的比较研究

目的探讨精神分裂症患者认知功能障碍的特点。方法对２３例以阴性症状为主的精神分裂症、３０例以阳性症状为主的精神分裂症和２８名正常人进行了威斯康星卡片分类测验（ＷＣＳＴ）。结果显示以阴性症状为主的精神分裂症患者的总测验次数、持续错误数和非持续错误数明显高于以阳性症状为主的精神分裂症患者和正常人，差异有显著性（Ｐ＜０．０５）。同时发现，ＷＣＳＴ的以上测验指标在两组患者之间差异亦有显著性（Ｐ＜０．０５）。相关分析显示，以阴性症状为主的精神分裂症患者的Ａｎｄｒｅａｓｅｎ阴性症状量表总分与简明精神病评定量表的迟滞因子分和持续错误数呈显著正相关（ｒ分别为０．４３７２和０．４５５１）。结论提示精神分裂症患者存在执行功能障碍，其中阴性症状可能与额叶功能缺陷有关。