Spatial working memory performance in patients with schizoaffective psychosis versus schizophrenia: a tale of two disorders?

We explored the relationship between schizophrenia and schizoaffective disorder by comparing the two patient groups in terms of their performance on measures of executive functioning (spatial working memory and Wisconsin Card Sorting Test). Patients with schizophrenia (N=34) and those with schizoaffective disorder (N=23) performed significantly poorer than community controls (N=30). However, the schizoaffective and schizophrenia groups did not differ from each other in terms of working memory accuracy or mean response latencies. Similarly, the two patient groups did not differ in terms of the number of categories achieved or number of perseverative errors on the Wisconsin Card Sorting Test. Among the patients, working memory accuracy was associated with number of WCST perseverative errors and number of categories achieved, though working memory performance was not associated with number of WCST nonperseverative errors. These findings indicate that both schizophrenia and schizoaffective disorder are associated with executive functioning deficits. The findings are discussed in the context of the ongoing debate regarding the conceptualization of schizoaffective disorder.     

精神分裂症患者与其健康同胞的注意和执行功能障碍的对照研究

目的　探讨精神分裂症患者及其健康同胞的注意、工作记忆 /执行功能的特点。方法对 5 0例精神分裂症患者 (患者组 )及其健康同胞 5 0名 (同胞组 ) ,以及 4 5名正常对照者 (正常对照组 )采用威斯康星卡片分类测验 (WCST)和持续操作测验 (CPT) ,评估注意、工作记忆 /执行功能。结果　(1)在WCST中 ,患者组及其同胞组的总测验次数 (分别为 83 4± 2 3 2和 74 1± 2 4 6 )、持续错误数 (分别为 2 5 8± 11 7和 2 2 8± 10 7)、随机错误数 (33 4± 19 2和 2 5 9± 17 1)均高于正常对照组 (分别为6 0 0± 2 1 6、14 8± 8 3和 18 1± 16 0 ;P <0 0 1)。 (2 )在CPT中 ,患者组的评分 [(2 8 4± 4 0 )分 ]低于同胞组 [(30 4± 2 3)分 ]和正常对照组 [(30 9± 2 8)分 ],而同胞组与正常对照组的差异无显著性(P >0 0 5 )。(3)患者组及其同胞组发生执行功能障碍 (分别为 2 9例和 2 5例 )和注意缺陷 (分别为 2 2例和 7例 )的例数均多于正常对照组 (分别为 9例和 4例 ;P <0 0 1) ,其中有工作记忆 /执行功能缺陷的精神分裂症患者 ,其同胞出现这一缺陷的比率 (6 6 % )高于无缺陷的精神分裂症患者的同胞 (2 8% )。(4)WCST中的持续错误数与文化程度呈负相关 (r =- 0 32 ,P <0 0 1) ,CPT与性别 (r=- 0 2     

首次发病与复发抑郁症患者执行功能的对照研究

目的:探讨首发和复发抑郁症患者执行功能损害情况。方法:采用威斯康星卡片分类测验(WCST)、Stroop测验、汉密尔顿抑郁量表(HAMD-17)对100例抑郁症患者进行评定,其中首次发病(首发组)患者41例,复发(复发组)患者59例;同时以50名正常人作为对照组进行测评并分析比较。结果:在WSCT的总错误数、分类完成数、持续性错误数及持续性应答数、以及Stroop色词测验的彩色文字阅读(Stroop-c)时间和彩色文字的色彩阅读(Stroop-cw)正确数上,首发组、复发组与对照组之间差异均有统计学意义(P0.05或P0.01);Stroop-c正确数上首发组和复发组之间差异无统计学意义(P0.05)。结论:无论首发还是复发抑郁症患者均存在明显的执行功能损害,复发者更为显著。     

抑郁症患者5-羟色胺转运体启动子区基因多态性和认知功能的听觉事件相关电位的研究

目的 探讨抑郁症患者的5-羟色胺转运体基因启动子区（5-HTTLPR）基因多态性分布特征和认知功能的损害特点.方法 运用聚合酶链反应-限制性片段长度多态（PCR-RFLP）测定60例抑郁症患者（研究组）和60例健康对照者（对照组）的5-HTTLPR基因多态性.应用汉密尔顿抑郁量表（HAMD）、威斯康星卡片分类测验（WCST）、事件相关电位P300对所有被试者进行抑郁和认知功能评定.结果 两组5-HTTLPR基因型频率和等位基因频率差异均无统计学意义（P＞0.05）.SS基因型患者HAMD分值明显高于LS型及LL型（P =0.003,P=0.004）.研究组WCST测评完成分类数低于对照组,持续性错误数、不能维持完整分类数高于对照组（P＜0.05）;研究组P300潜伏期延长、P300波幅降低（P＜0.05）.研究组P300潜伏期与错误应答数呈正相关（r=0.817,P=0.034）.结论 5-HTTLPR基因多态性与抑郁症的发病无相关性,但与抑郁症的严重程度相关;抑郁症患者存在认知功能障碍,其中执行功能和注意功能的降低较为显著.     

Frontal P300 Decrement and Executive Dysfunction in Adolescents with Conduct Problems

This study investigated the cognitive and cerebral function of adolescents with conduct problems by neuropsychological battery (STIM) and event-related potential (ERP). Eighteen adolescents with conduct disorder, and 18 age-matched normal subjects were included. Such cognitive functions as attention, memory, executive function and problem solving were evaluated using subtests of STIM. ERP was measured using an auditory oddball paradigm. The conduct group showed a significantly lower hit rate on the Wisconsin Card Sorting Test (WCST) than the control group. In addition, the conduct group showed reduced P300 amplitude at Fz and Cz, and prolonged P300 latency at Fz, and there was a significant correlation between P300 amplitude and Stroop test performance. These results indicate that adolescents with conduct problems have impairments of executive function and inhibition, and that these impairments are associated with frontal dysfunction.     

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.     

Poor sleep and neurocognitive function in early adolescence

BackgroundEvidence regarding the associations between sleep duration and quality, and neurocognitive function in adolescents remains scanty. This study examined the associations in early adolescence between: sleep duration; efficiency; fragmentation; wake-after-sleep-onset (WASO); catch-up sleep; intelligence; memory; and executive function, including attention.MethodsThis study included 354 girls and boys with a mean age 12.3 years (SD = 0.5) from a birth cohort born in 1998. Sleep was measured with accelerometers for an average of eight nights. Cognitive function was evaluated with subtests from the Wechsler Intelligence Scale for Children-III (WISC-III), the Developmental Neuropsychological Assessment 2 (NEPSY-2), the Wisconsin Card Sorting Task (WCST), Conners' Continuous Performance Task (CPT), and the Trail Making Test (TMT).ResultsIn girls, a higher WASO and fragmentation index were associated with poorer executive functioning (higher number of perseverative errors in the WCST), and longer catch-up sleep was associated with longer reaction times and better performance in one verbal intelligence test (Similarities subtest of the WISC-III). In boys, shorter sleep duration, lower efficiency, higher WASO, higher sleep fragmentation and shorter catch-up sleep were associated with lower executive functioning (more commission errors, shorter reaction times, and had lower D Prime scores in CPT).ConclusionsIn adolescent girls, poorer sleep quality was only weakly associated with poorer executive functioning, while in boys, poorer sleep quantity and quality were associated with an inattentive pattern of executive functioning. The amount of catch-up sleep during weekends showed mixed patterns in relation to neurocognitive function.     

Genetic influences on frontal brain function: WCST performance in twins

The Wisconsin Card Sorting Test (WCST) is one of the most widely used assessments of executive functioning related to prefrontal cortex. However, little is known about genetic and environmental determinants of individual differences in WCST performance. This study assessed heritability of standard WCST scores in a sample of 168 young female twins including 58 monozygotic and 25 dizygotic pairs. Several WSCT indices, including the number and percentage of errors, the number of perseverative responses, and the number and percent of perseverative errors, showed significant heritability ranging from 37 to 46%. The results suggest that selected aspects of frontal executive functioning measured by the WCST are moderately influenced by genetic factors.     

Schizophrenic subjects show deficient inhibition but intact task switching on saccadic tasks.

BACKGROUND: Schizophrenic patients have executive function deficits, presumably on the basis of prefrontal cortex dysfunction. Although they consistently show impaired inhibition, the evidence of a task switching deficit is less consistent and is often based on performance of neuropsychological tests that require several cognitive processes (e.g., the Wisconsin Card Sort Test [WCST]). We investigated inhibition and task switching using saccadic tasks to determine whether schizophrenic patients have selective impairments of these executive functions. METHODS: Sixteen normal and 21 schizophrenic subjects performed blocks of randomly mixed prosaccade and antisaccade trials. This gave rise to four trial types: prosaccades and antisaccades that were either repeated or switched. Response accuracy and latency were measured. Schizophrenic subjects also performed the WCST. RESULTS: Schizophrenic subjects showed abnormal antisaccade and WCST performance. In contrast, task switching was normal and unrelated to either antisaccade or WCST performance. CONCLUSIONS: The finding of intact task switching performance that is unrelated to other measures of executive function demonstrates selective rather than general impairments of executive functions in schizophrenia. The findings also suggest that abnormal WCST performance is unlikely to be a consequence of deficient task switching. We hypothesize that inhibition and task switching are mediated by distinct neural networks, only one of which is dysfunctional in schizophrenia.     

Dissociation of ketamine effects on rule acquisition and rule implementation: possible relevance to NMDA receptor contributions to executive cognitive functions.

BACKGROUND: The demands of the Wisconsin Card Sorting Test (WCST) change with experience. This report contains two studies designed to examine N-methyl-D-aspartate (NMDA) receptor contributions to the executive components of WCST performance. These aspects of WCST performance figure more prominently in the initial completion of this task than in subsequent task repetitions in healthy populations. METHODS: In the first study, healthy subjects (n = 15) completed the WCST on two occasions separated by 1 week. In the second study, healthy subjects (n = 22) completed two test days spaced by approximately 1 week, during which, they completed the WCST and other assessments after administration of the NMDA antagonist ketamine (intravenous bolus 0.26 mg/kg followed by infusion of 0.65 mg/kg/hour) or matched placebo. RESULTS: In the first study, subjects reduced the number of total and perseverative errors with a single repetition of the WCST. In the second study, ketamine significantly increased the number of total errors and the number and percent of perseverative errors on the first, but not the second test day. Similarly, it reduced the number of category criteria met on the first, but not second test day. Ketamine also increased distractibility, impaired recall, produced psychosis, altered perception, and had effects resembling the negative symptoms of schizophrenia. However, only WCST performance showed order dependency. CONCLUSIONS: This order dependency further implicates NMDA receptors in executive cognitive functions associated with the frontal cortex.     

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.     

Caudate atrophy and impaired frontostriatal connections are linked to executive dysfunction in temporal lobe epilepsy

This study tested the hypothesis that executive dysfunction, common in temporal lobe epilepsy (TLE), is associated with an abnormal frontostriatal network. Structural and diffusion tensor MR scans, the Wisconsin Card Sorting Test (WCST) targeting cognitive flexibility, and the Trail Making Test B examining parallel sequencing were obtained from 9 patients with left TLE and 17 healthy controls. The five major findings were: (1) Caudate volume is reduced on the left side in TLE. (2) The atrophy involves the dorsal and ventral head of the caudate. (3) These atrophic caudate regions have a corresponding high probability of connections to dorsal prefrontal, anterior cingulate, and orbitofrontal cortex. (4) Smaller caudate volumes are linked to greater numbers of WCST perseverative errors. (5) Reduced connections between caudate and dorsal prefrontal cortex correlated with poorer scores on the Trail Making Test B. The results suggest that atrophy in the dorsal head of the caudate might disrupt frontostriatal networks that are critical for executive functioning in TLE.     

Performance in the Wisconsin Card Sorting Test and the C957T polymorphism of the DRD2 gene in healthy volunteers

INTRODUCTION: Previous studies have associated a decreased striatal D2 dopamine receptor (DRD2) binding with impaired performance in cognitive tasks. In vivo studies have found a lower DRD2 binding associated with the CC genotype of the C957T single nucleotide polymorphism (SNP) of the DRD2 gene. OBJECTIVE: The aim of this study was to investigate the relationship between executive functions and the C957T DRD2 SNP. We hypothesized that the CC genotype would be associated with a poorer executive functioning. METHODS: Our sample consisted of 83 healthy volunteers (28 males and 55 females; mean age 25.2, SD 1.7 years). To assess executive functions, the Wisconsin Card Sorting Test was used, considering the variables perseverative errors, perseverative responses, and number of categories achieved. The genotype distribution was 13 CC, 41 CT, and 29 TT, satisfying Hardy-Weinberg equilibrium. RESULTS: Carriers of the CC genotype, compared with carriers of the CT/TT genotypes, achieved significantly fewer categories (5.00 vs. 5.81; p = 0.004), made a greater number of perseverative errors (13.46 vs. 8.39; p = 0.018), and had a greater number of perseverative responses (14.92 vs. 8.94; p = 0.014). CONCLUSIONS: Our results support the hypothesis that the C957T DRD2 SNP may influence cognitive performance through its repercussions on central dopaminergic function.     

事件相关电位P300对慢性精神分裂症认知功能的评估

目的：探讨事件相关电位P300在评估慢性精神分裂症认知功能中的价值。方法：应用事件相关电位P300、韦氏记忆量表（WMS）、韦氏成人智力量表（WAIS-RC）及威斯康星卡片分类测验（WCST）分别对60例慢性精神分裂症患者（患者组）与60名健康志愿者（对照组）进行测查,分析P300潜伏期、波幅与神经心理学测验成绩的相关性。结果：患者组P300潜伏期延长及波幅降低,言语智商、操作智商、韦氏记忆商、WCST各项指标均低于对照组（P〈0.05）。P300潜伏期与操作智商、持续性错误百分数、随机错误百分数呈负相关;波幅与短时记忆、随机错误百分数呈正相关。结论：慢性精神分裂症患者存在全面的认知功能损害,P300潜伏期和波幅可作为其客观评估指标。     

Prefrontal executive function and D1, D3, 5-HT2A and 5-HT6 receptor gene variations in healthy adults

OBJECTIVE: The Val158Met polymorphism of the catechol-O-methyltransferase gene has been demonstrated to be associated with prefrontal executive function explaining 4% of variance in perseverative errors on the Wisconsin Card Sorting Test (WCST). Studies suggest that dopamine D(1) and D(3) and serotonin 5-HT(2A) and 5-HT(6) receptors may also be involved in prefrontal cognitive function and that genetic polymorphisms (D(1) A-48G, D(3) Ser9Gly, 5-HT(2A) T102C, and 5-HT(6) T267C) of these receptors may be associated with brain glucose metabolism or neurophysiological function. The current study's objective was to investigate whether executive function varies with these genetic variations. METHODS: A sample of 216 healthy Han Chinese adults were measured with the WCST and genotyped for the 4 genetic polymorphisms. RESULTS: Kruskal-Wallis tests showed a significant difference in WCST perseverative errors among the genotypes D(3) Ser9Gly (p = 0.009), 5-HT(2A) T102C (p = 0.038) and 5-HT(6) T267C (p = 0.010), but not in the genotype D(1) A-48G. Multiple regression analysis for the WCST natural logarithm values (i.e., for fulfilling the normal distribution requirement) showed that subjects' perseverative errors were significantly influenced by D(1) A-48G, D(3) Ser9Gly, 5-HT(2A) T102C and 5-HT(6) T267C polymorphisms after adjustment of other variables. CONCLUSION: The preliminary data suggest that D(1), D(3), 5-HT(2A) and 5-HT(6) genetic mutations may influence prefrontal executive cognition in healthy adults. Further studies in larger samples with other ethnicities or in mentally ill patients are warranted.     

Wisconsin Card Sorting performance in patients with temporal lobe epilepsy: clinical and neuroanatomical correlates

PURPOSE: A sizable proportion of patients with temporal lobe epilepsy (TLE) display impairments on tests of executive function. Previous studies have suggested several factors that may explain such performance, including the presence of hippocampal sclerosis, electrophysiological disruption to extratemporal regions, and early age of seizure onset. However, no clear determinants have been found that consistently explain such executive dysfunction. The present study investigated the contribution of several clinical variables and temporal lobe neuroanatomic features to performance on the Wisconsin Card Sorting Test (WCST) in a series of patients with TLE. METHODS: Eighty-nine patients with lateralized TLE (47 left, 42 right) were examined. Seventy-two patients from this series underwent anterior temporal lobectomy (ATL). Regression analysis was used to examine the effects of age, education, age at seizure onset, seizure duration, seizure laterality, history of secondary generalized seizures, and MRI-based volumes of the right and left hippocampi on preoperative WCST performance (number of categories completed, perseverative errors). Further univariate analyses examined whether the presence of bilateral hippocampal sclerosis, mesial temporal lobe abnormalities beyond the hippocampus, or temporal neocortical abnormalities affected preoperative WCST performance. In addition, we examined whether becoming seizure free after ATL affected change in WCST performance. RESULTS: Overall regression analysis was not significant. However, an examination of individual partial correlations revealed that patients with a history of secondary generalized seizures performed more poorly on the preoperative WCST than did patients without such history. In addition, patients who were seizure free after ATL did not exhibit better WCST outcome than patients who did not become seizure free. The presence of bilateral hippocampal sclerosis, extrahippocampal mesial temporal atrophy, or temporal neocortical lesions did not affect WCST performance. CONCLUSIONS: These results indicate that the presence of temporal lobe structural abnormalities do not significantly affect executive function as measured by the WCST. The present study does suggests that the critical determinants of WCST performance in patients with TLE lie outside the temporal lobe and likely relate to metabolic disruption to frontostriatal neural network systems.     

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.     

The Impact of Executive Function on Emotion Recognition and Emotion Experience in Patients with Schizophrenia

Objective

This study investigated the impact of executive function on the performance of two different affective tasks, the Facial Affect Identification Task (FAIT) and the Iowa Gambling Task (IGT), in patients with schizophrenia.

Methods

Thirty-nine patients with schizophrenia and 33 healthy controls completed the FAIT and the IGT, followed by the Wisconsin Card Sorting Test (WCST) and the intelligence quotient (IQ) test. In addition to correlation analysis, regression analysis was used to determine the extent to which the performance of the WCST, in particular, perseverative error (PE), accounted for the variation in both the FAIT and the IGT.

Results

Relative to normal controls, patients with schizophrenia showed significant impairments in the IGT, the FAIT and the WCST even after controlling for IQ. While normal controls did not show any relationships between the WCST and two affective tasks, patients with schizophrenia showed that variables in the WCST correlated not only with the FAIT total correct score (r=-0.503, p=0.001 for PE) but also with the IGT net score (r=0.385, p=0.016 for PE). The PE score was a better predictor of the performance on the FAIT (R²=0.25) than that of the performance on the IGT (R²=0.15).

Conclusion

Our findings imply that deficits in executive function in schizophrenia can affect performance on facial emotion recognition task more than performance on task based on emotion experience, that is, the feedback from the body. Therefore, more consideration is needed of the impact of executive function when interpreting the result of "conventional" facial affect recognition tests as opposed to interpreting the IGT.     

Reduced hippocampal volume correlates with executive dysfunctioning in major depression

OBJECTIVE: Dysfunction of neuronal plasticity or remodelling seems to contribute to the pathopysiology of major depression and may cause the well-documented hippocampal changes in depression. We aimed to investigate whether reduced hippocampal volumes correlate with executive dysfunctioning or memory dysfunctioning or with depression severity. METHODS: We recruited 34 inpatients with a previous or current episode of major depression from the department of psychiatry at the Ludwig-Maximilians University of Munich, Germany. We examined the 34 patients and 34 healthy control subjects with structural high resolution MRI. We assessed cognitive functions with the Wisconsin Card Sorting Test (WCST) and the Rey Auditory Verbal Learning Test (RAVLT) and severity of depression with the Hamilton Depression Rating Scale. RESULTS: Hippocampal volumes and frontal lobe volumes were significantly smaller in patients, compared with healthy control subjects. Furthermore, lower hippocampal volumes were correlated with poorer performance in the WCST. No significant correlations were found between hippocampal volumes and RAVLT performance or severity of depression. CONCLUSIONS: The present findings emphasize that patients with reduced hippocampal volumes show more executive dysfunctions than their counterparts. Thus, the mechanisms resulting in reduced hippocampal volumes seem to be related to the development of major depression.     

Declarative memory and WCST-64 performance in subjects with schizophrenia and healthy controls

The Wisconsin Card Sorting Test (WCST) is a set-switching task used extensively to study impaired executive functioning in schizophrenia. Declarative memory deficits have also been associated with schizophrenia and may affect WCST performance because continued correct responding depends on remembering the outcome of previous responses. This study examined whether performance in visual and verbal declarative memory tasks were associated with WCST performance. Subjects comprised 30 patients with schizophrenia or schizoaffective disorder (SCZ) and 30 demographically matched healthy controls (CON) who were tested on the WCST, the Benton Visual Retention Test (BVRT), the California Verbal Learning Test (CVLT), and the Continuous Performance Test (CPT). SCZ subjects showed significant correlations between visual and verbal declarative memory and performance on the WCST-64 that were in the hypothesized direction such that worse memory performance was associated with worse performance on the WCST. CON subjects did not show a significant relationship between visual or verbal memory and WCST-64 performance. Fisher's r to z transformations indicated that the associations between declarative memory and WCST-64 performance in the SCZ subjects differed significantly from those of CON subjects. The findings suggest that interpretations of WCST-64 scores for subjects with schizophrenia should be considered in light of their declarative memory functioning.