Executive dysfunctions as potential markers of familial vulnerability to bipolar disorder and schizophrenia

Attentional and executive impairments have been found both in patients with schizophrenia and in their unaffected first-degree relatives, suggesting that they might be considered as familial vulnerability markers. Several studies have shown that the performance of bipolar patients does not significantly differ from that of schizophrenic patients, so that executive and attentional deficits might not be specific to schizophrenia. In the present study, we aimed to identify executive dysfunctions in schizophrenia and bipolar disorder that might be vulnerability trait markers specific to one or common to both of these diseases. We assessed cognitive performance of euthymic bipolar and schizophrenic patients, their unaffected first-degree relatives and a healthy control group, using neuropsychological tasks to test different components of executive function: the Verbal Fluency Test, the Stroop Word Colour Test, the Wisconsin Card Sorting Test and the Trail Making Test. The two groups of patients and their unaffected relatives demonstrated disproportionately increased slowness on the Stroop test in comparison to the normal healthy group. Patients with schizophrenia performed poorly on all the tests in comparison to the normal healthy subjects, while no other impairment was observed in the bipolar patients and in the relatives of schizophrenic and bipolar patients. Enhanced susceptibility to interference and reduced inhibition could be transnosographical markers for a shared familial vulnerability common to schizophrenia and bipolar disorders.     

Cerebellar Cognitive Affective Syndrome in Machado Joseph Disease: Core Clinical Features

The cerebellum is no longer considered a purely motor control device, and convincing evidence has demonstrated its relationship to cognitive and emotional neural circuits. The aims of the present study were to establish the core cognitive features in our patient population and to determine the presence of Cerebellar Cognitive Affective Syndrome (CCAS) in this group. We recruited 38 patients with spinocerebellar ataxia type 3 (SCA3) or Machado–Joseph disease (MJD)-SCA3/MJD and 31 controls. Data on disease status were recorded (disease duration, age, age at onset, ataxia severity, and CAG repeat length). The severity of cerebellar symptoms was measured using the International Cooperative Ataxia Rating Scale and the Scale for the Assessment and Rating of Ataxia. The neuropsychological assessment consisted of the Mini-Mental State Examination, Clock Drawing Test, Wechsler Adult Intelligence Scale, Rey–Osterrieth Complex Figure, Wisconsin Card Sorting Test, Stroop Color–Word Test, Trail-Making Test, Verbal Paired Associates, and verbal fluency tests. All subjects were also submitted to the Hamilton Anxiety Scale and Beck Depression Inventory. After controlling for multiple comparisons, spatial span, picture completion, symbol search, Stroop Color–Word Test, phonemic verbal fluency, and Trail-Making Tests A and B were significantly more impaired in patients with SCA3/MJD than in controls. Executive and visuospatial functions are impaired in patients with SCA3/MJD, consistent with the symptoms reported in the CCAS. We speculate on a possible role in visual cortical processing degeneration and executive dysfunction in our patients as a model to explain their main cognitive deficit.     

Stroop interference associated with efficient reading fluency and prelexical orthographic processing

The Stroop Color–Word Test involves a dynamic interplay between reading and executive functioning that elicits intuitions of word reading automaticity. One such intuition is that strong reading skills (i.e., more automatized word reading) play a disruptive role within the test, contributing to Stroop interference. However, evidence has accumulated that challenges this intuition. The present study examined associations among Stroop interference, reading skills (i.e., isolated word identification, grapheme-to-phoneme mapping, phonemic awareness, reading fluency) measured on standardized tests, and orthographic skills measured on experimental computerized tasks. Among university students (N = 152), correlational analyses showed greater Stroop interference to be associated with (a) relatively low scores on all standardized reading tests, and (b) longer response latencies on orthographic tasks. Hierarchical regression demonstrated that reading fluency and prelexical orthographic processing predicted unique and significant variance in Stroop interference beyond baseline rapid naming. Results suggest that strong reading skills, including orthographic processing, play a supportive role in resolving Stroop interference.     

Cognitive functions and serum levels of brain-derived neurotrophic factor in patients with major depressive disorder

Objective

We assessed major cognitive domains in major depressive disorder (MDD) compared to a healthy control group using neurocognitive tests. We hypothesized that lower serum brain-derived neurotrophic factor (BDNF) levels would be associated with poorer neurocognitive performance in patients with major depression and that these associations would be shown in healthy controls as well.

Method

Executive functions, sustaining and focusing of attention, memory functions, and verbal fluency were assessed in this study using the Trail-Making Test (TMT), Stroop Color Word Interference Test-TBAG Form (SCWT), Wisconsin Card Sorting Test (WCST), Test of Variables of Attention (TOVA), Auditory Consonant Trigram test (ACTT), Digit Span subtest of the Wechsler Memory Scale (DST), Rey Auditory Verbal Learning Test (RAVLT), and Controlled Oral Word Association Test (COWAT).

Results

The MDD group showed significantly poorer performance than the control group in cognitive functions; they also had lower levels of BDNF than the control group. However, there was no correlation between cognitive performances and BDNF levels except in the TMT, Part B.

Conclusions

The current understanding of the importance of neurocognitive assessment and related biological markers in depression is improving. Further studies with larger sample sizes evaluating neurocognitive functions with molecular analyses of BDNF levels may reveal a novel marker for predicting and monitoring neurocognitive deficits in depression.     

Investigating the relationship between sexual and chemical addictions by comparing executive function in subjects with pedophilia or opiate addiction and healthy controls

Disorders of driven sexual behavior have been conceptualized as sexual addictions. In the following study, we compared 51 subjects with pedophilia, 53 subjects with opiate addiction, and 84 healthy control subjects on neuropsychological tests that tap executive functions. The test battery included the Wisconsin Card Sorting Test (WCST), Stroop Color-Word Test, the Matching Familiar Figures Test (MFFT), Porteus Mazes, Controlled Word Association (COWA), and Trailmaking Test. The groups differed on tests of cognitive flexibility and set switching (WCST), sustained attention (Stroop), and impulsivity (MFFT and Porteus Mazes). There were no differences on verbal fluency (COWA). The subjects with pedophilia differed significantly from those with opiate addiction on several tests, with longer latency to response on MFFT and fewer completed mazes but also fewer errors on Porteus Mazes. Thus, while both subjects with pedophilia and those with opiate addiction show executive dysfunction, the nature of that dysfunction may differ between the two groups; specifically, opiate addicted subjects may be more prone to cognitive impulsivity.     

Heterogeneity in executive impairment in patients with very mild Alzheimer's disease

BACKGROUND/AIMS: The presence of executive impairment in mild Alzheimer's disease (AD) has primarily been demonstrated by means of group comparison. Whether executive dysfunction is a common feature of mild AD or only present in a subgroup of patients remains unclear. The aim of this study was to describe the frequency of impairment on a set of internationally well-known executive tests in patients with very mild AD. METHODS: Thirty-six patients with very mild AD (MMSE scores above 23) and 32 healthy control subjects were administered a battery of 7 executive tests: Trail Making part B, Stroop Interference Test, modified Wisconsin Card Sorting Test (WCST), category- and letter-based verbal fluency, a design fluency task and the Similarities subtest from WAIS. Impairment was defined as a score of 2 SD or more below control means. RESULTS: Executive impairment on at least 1 measure was seen in 76% of the patients, and 50% were impaired on 2 or more tests. Trail Making B and Stroop Interference Test were impaired in more than 40%, whereas only few patients were impaired on Similarities, WCST and design fluency. A wide variation of executive test profiles was seen among the patients. CONCLUSION: Executive impairments are common in early AD and not just a feature characteristic of a subgroup of patients. Complex attentional skills are more frequently affected than other executive functions. There is, however, considerable heterogeneity among AD patients in the pattern of executive dysfunction.     

Cognitive patterns in subtypes of schizophrenia.

AIM: Because of the heterogeneity of schizophrenia, this study researched different cognitive patterns in distinct subtypes of schizophrenic patients. METHODS: Thirty-five Diagnostic and Statistical Manual IV (DSM IV) schizophrenic patients and 35 healthy controls were included. Patients were categorized into deficit, disorganized and positive subtypes with the schedule for the deficit syndrome (SDS) and the positive and negative syndrome scale (PANSS). Executive/attentional functions were assessed with the modified card sorting test (MCST), a test of verbal fluency, the trail making test (TMT) and the Stroop color-word test (Stroop test). Episodic memory was explored through the California verbal learning test (CVLT). RESULTS: The positive subtype had some executive/attentional (fluency and Stroop tests) and mnesic performances in the normal range, suggesting the preservation of good cognitive skills. In contrast, the deficit and disorganized subtypes had major mnesic and executive/attentional dysfunctions compared to healthy subjects. The deficit subtype compared to the control group performed predominantly worse on the MCST and fluency, whereas the disorganized subtype had the lowest scores on the TMT and the Stroop test. CONCLUSION: This study showed distinct cognitive patterns in deficit, disorganized and positive patients in comparison with the controls, suggesting a heterogeneous cognitive dysfunction in schizophrenia.     

Cognitive effects of unilateral posteroventral pallidotomy: a 4-year follow-up study.

We assessed the long-term neuropsychological effects of unilateral posteroventral pallidotomy in Parkinson's disease. Eleven Parkinson's disease patients, from an original cohort of 15 consecutive patients who underwent pallidotomy, were evaluated. A neuropsychological battery was administered to each patient before (3 days) and after (3 months and 4 years) surgery during the effects of levodopa. The following tests were administered: Rey's Auditory-Verbal Learning Test, Visual Associative Learning test from the Wechsler Memory Scale-Revised, Luria's motor alternation, Benton's Judgment of Line Orientation, Trail Making, phonetic verbal fluency, Stroop test, Petrides' working memory tasks, Beck's depression questionnaire and the Maudsley obsessional-compulsive inventory. In the 3-month postoperative assessment, there was a significant worsening in phonetic verbal fluency and an improvement in Benton's Judgment of Line Orientation test. In the 4-year follow-up assessment, phonetic verbal fluency and Benton's Judgment of Line Orientation test returned to baseline scores. Although there was no significant difference between pre- and postsurgical scores for long-term visual associative memory, there was a significant deterioration between 3-month and 4-year follow-up performances. Our results suggest that unilateral posteroventral pallidotomy may produce transient changes in prefrontal and visuospatial functions, but there is no evidence of permanent neuropsychological effects.     

Humor appreciation deficit in schizophrenia: the relevance of basic neurocognitive functioning

The purpose in undertaking the present study was to investigate humor appreciation in patients with schizophrenia. Moreover, we sought to explore the potential relationship of humor appreciation with measures of psychopathology and cognitive functioning among the patients. Thirty-six patients with schizophrenia were compared with 31 normal controls matched for age, sex, and education on a computerized test comprising captionless cartoons: Penn's Humor Appreciation Test (PHAT). The patients were also evaluated on the symptom dimensions derived from the Positive and Negative Symptom Scale (positive symptoms, negative symptoms, cognitive symptoms, depression, and excitement), as well as a battery of neuropsychological tests measuring executive functions, attention, working memory, verbal and visual memory, visuospatial ability, and psychomotor speed. Patients with schizophrenia had significantly lower scores on the PHAT than normal controls. The patients' performance on the PHAT correlated with scores on Penn's Continuous Performance Test, the Stroop Color-Word Test, and the phonological subscale of the Greek Verbal Fluency Test. Our findings indicated impaired humor appreciation among patients with schizophrenia. The relationship found between the appreciation of captionless cartoons involved an incongruous detail and performance on a broad neuropsychological battery suggested that the deficit in humor appreciation in schizophrenia could be attributed to impairment in more basic neurocognitive domains, namely, selective and sustained attention as well as phonological word fluency.     

The selective attention deficit in schizophrenia. Limited resources or cognitive fatigue?

The Stroop Word-Color Test was used to study selective attention deficits in schizophrenic and nonschizophrenic psychiatric patients, compared with nonpsychiatric control subjects. Parts of the Weschler Memory Test and a shortened version of the Stroop Test were administered to test the hypotheses that the attentional deficit could be explained by problems of memory or cognitive fatigue. All patients showed deficits on all of the Stroop scales, but closer analysis of the results permitted discrimination of schizophrenic from nonschizophrenic patients. Schizophrenic patients showed as much difficulty as nonschizophrenic subjects on a limited-duration selective-attention task, but deteriorated significantly more when selective attention had to be maintained. The results could not be attributed to memory problems in the schizophrenic group. The results support the existence of two separable selective attention deficits in schizophrenic patients: a difficulty in selectively attending to the salient aspect of a complex stimulus, a difficulty shared with nonschizophrenic subjects, and a difficulty in maintaining selective attention over time that seems to be more marked in schizophrenic subjects.     

Bradykinesia in early Huntington's disease

BACKGROUND: Huntington's disease (HD) is generally considered a hyperkinetic disorder, although hypokinetic features are part of the motor syndrome. Moreover, the striatum is considered to play a key role in initiating and executing motor programs and achieving optimal scheduling in response generation. Controversial results regarding the association between clinical features and markers of progression of the disease might be the result of inadequate restriction of clinical signs to the choreatic syndrome. OBJECTIVE: To determine the relationship of neurologic motor and cognitive indices in patients with HD with intrinsic neuronal loss in the striatum, as measured using raclopride C11 and PET. PATIENTS AND METHODS: A cross-sectional study was performed on 11 patients with mild HD (stages 0-2). Motor (Unified Huntington's Disease Rating Scale [UHDRS], saccadic and tapping speed) and cognitive (verbal fluency, Trail Making Test, Stroop Test, Symbol Digit Modalities Test, Conditioned Associative Learning Test, and silhouette identification and object decision of the Visual Object and Space Perception battery) scores were correlated with raclopride C11 binding. RESULTS: Bradykinesia (a summation of five items of the UHDRS motor scale) was the best predictor for stage, that is, functional capacity, and showed a highly significant relationship with putaminous D2 binding (r = -0.94) and with CAG expansion length x years of age (r = 0.96). The exclusion of two patients with a rigid-akinetic HD variant did not alter these coefficients. Chorea was less well correlated than bradykinesia with D2 binding in all striatal regions. Performance on different cognitive tests, especially in timed tasks, was highly correlated with raclopride C11 binding in caudate nucleus and ventral striatum. CONCLUSION: Loss of D2 binding in the striatum is highly correlated with the deficit in fast motor and cognitive processing in patients with early Huntington's Disease. Thus, impairment of rapid execution of adequate responses to environmental changes seems to be a common manifestation of striatal disorders.     

The neuropsychological correlates of borderline personality disorder and suicidal behaviour.

OBJECTIVE: In subjects with borderline personality disorder (BPD), compared with subjects who attempted suicide, to review neuropsychological (NP) function that may predispose to suicidal behaviour along a continuum of high and low lethality. METHOD: We undertook electronic searches of MEDLINE, PsycINFO, EMBASE, Biosos Reviews, and Cinhal. The searches were restricted to English-language publications from 1985 onward. The search terms borderline personality disorder, suicide, suicide attempt, self-harm behaviour, neuropsychological, executive function (EF), neurocognitive, and neuropsychological function produced 29 neuropsychology studies involving BPD and 7 neuropsychology studies of suicide attempters, regardless of psychiatric diagnosis. RESULTS: Of the BPD studies, 83% found NP impairment in one or more cognitive domains, irrespective of depression, involving specific or generalized deficits linked to the dorsolateral prefrontal and orbitofrontal regions. The functions most frequently reported (in 71% to 86% of BPD studies) are response-inhibitory processes affecting executive function performance that requires speeded attention and visuomotor skills. Decision making and visual memory impairment are also most frequently affected; 60% to 67% of BPD studies report attentional impairment, verbal memory impairment, and visuospatial organizational impairment. Least affected processes in BPD appear to involve spatial working memory, planning, and possibly, IQ. The similarities in NP deficits found in BPD and suicide-attempt studies involve decision making and Trails performances. BPD studies, however, reflect more frequent impairment on the Stroop Test and Wisconsin Card Sort Test performance than the suicide-attempt studies, whereas verbal fluency appears to be more frequently impaired in those attempting suicide. CONCLUSIONS: Impaired EF and disinhibitory processes, as indicated by verbal fluency, Trails, and Stroop performance, primarily associated with dorsolateral prefrontal cortical regions may represent a dominant executive pathway to suicide attempt. A primary motivational inhibitory pathway involving conflictual, affective, and reflexive decision-making processes associated with orbitofrontal brain regions, in combination with significant cognitive rigidity, may influence the repetitive expression of self-harm or low-lethality suicidal behaviour. The hypothesis of a specific trait-like cognitive vulnerability for suicidal behaviour involving dysregulatory, disinhibiting pathways awaits confirmation.     

Language impairment in Huntington's disease

Language alterations in Huntington's disease (HD) are reported, but their nature and correlation with other cognitive impairments are still under investigation. This study aimed to characterize the language disturbances in HD and to correlate them to motor and cognitive aspects of the disease. We studied 23 HD patients and 23 controls, matched for age and schooling, using the Boston Diagnostic Aphasia Examination, Boston Naming Test, the Token Test, Animal fluency, Action fluency, FAS-COWA, the Symbol Digit Modalities Test, the Stroop Test and the Hooper Visual Organization Test (HVOT). HD patients performed poorer in verbal fluency (p<0.0001), oral comprehension (p<0.0001), repetition (p<0.0001), oral agility (p<0.0001), reading comprehension (p=0.034) and narrative writing (p<0.0001). There was a moderate correlation between the Expressive Component and Language Competency Indexes and the HVOT (r=0.519, p=0.011 and r=0.450, p=0.031, respectively). Language alterations in HD seem to reflect a derangement in both frontostriatal and frontotemporal regions.     

Moderator variables of executive functioning in schizophrenia: meta-analytic findings

The literature regarding executive functioning in schizophrenia was examined to determine effect size differences between schizophrenic, normal control, and psychiatric groups. Effect sizes (n = 176) from 71 studies were cumulated across measures including the Wisconsin Card Sorting Test (WCST), Halstead Category Test (HCT), verbal/design fluency, Trail Making B (TMB), and the Stroop Color-Word Test. Schizophrenic groups were impaired relative to controls (delta = -1.45). Schizophrenic groups also performed 0.40 standard deviations lower than psychiatric groups. Within the schizophrenic versus normal control comparisons, the effect size based on complex measures, such as the WCST/HCT (delta = -1.42), was similar to that based on less complex measures, such as TMB and the Stroop (delta = -1.58). Chlorpromazine equivalents and illness duration were not significantly correlated with effect sizes (p > 0.05). Effect sizes and number of hospitalizations (p < 0.05) were related. Effect sizes and Brief Psychiatric Rating Scale (BPRS) were not significantly correlated. Negative and positive symptoms were significantly correlated (p < 0.05). The results as they apply to research and clinical practice are discussed.     

The effects of bilateral subthalamic nucleus deep brain stimulation (STN DBS) on cognition in Parkinson disease

The effects of subthalamic nucleus (STN) stimulation on cognition and mood have not been well established. The authors estimated cognitive and mood effects of bilateral subthalamic nucleus deep brain stimulation (STN DBS) in patients with Parkinson's disease (PD) at 6 months and 1 year postoperatively. Forty-six patients were recruited from the Movement Disorder Center at Seoul National University Hospital. Neuropsychologic tests were performed three times, before, 6 months after, and 1 year after surgery. Mean patient age was 58 and mean education duration 8 years. Eighteen of the 46 patients were men. The instruments used for assessing cognitive functions were; the Mini-Mental Status Examination (MMSE), the Trail Making Test (TMT), the Korean Boston Naming Test (K-BNT), the Rey-Kim Memory Battery, the Grooved pegboard test, the Stroop test, a fluency test, the Wisconsin Card Sorting test (WCST), and the Beck depression inventory (BDI). Of these tests, the verbal memory test, the Stroop test, and the fluency test showed statistically significant changes. The verbal memory test using the Rey-Kim memory battery showed a decline in delayed recall and recognition at 6 months and 1 year postoperatively, whereas nonverbal memory showed no meaningful change. In terms of frontal lobe function tests, Stroop test and fluency test findings were found to be aggravated at 6 months and this continued at 1 year postoperatively. Previous studies have consistently reported a reduction in verbal fluency and improvements in self-reported symptoms of depression after STN DBS. However, in the present study, Beck depression inventory (B.D.I.) was not significantly changed. Other tests, namely, MMSE, TMT, K-BNT, Grooved pegboard test, and the WCST also failed to show significant changes. Of the baseline characteristics, age at onset, number of years in full-time education, and l-dopa equivalent dosage were found to be correlated with a postoperative decline in neuropsychological test results. The correlation of motor improvement and cognitive deterioration was not significant, which suggests that the stimulation effect is rather confined to the motor-related part in the STN. In conclusion, bilateral STN DBS in Parkinson's disease did not lead to a significant global deterioration in cognitive function. However, our findings suggest that it has minor detrimental long-term impacts on memory and frontal lobe function.     

Psychomotor slowing as a predictor of fluoxetine nonresponse in depressed outpatients

OBJECTIVE: This study examined the utility of baseline psychomotor speed, measured with neuropsychological tests, to predict fluoxetine response in moderately depressed outpatients. The authors hypothesized that since psychomotor slowing in depressed patients has been linked to reduced dopaminergic neurotransmission, patients with slowing would be unresponsive to fluoxetine, a selective serotonin reuptake inhibitor. METHOD: After baseline neuropsychological testing, patients were treated openly with fluoxetine for 12 weeks. Thirty-seven patients completed the trial. RESULTS: Compared to the 25 patients who responded, the 12 patients who did not respond to fluoxetine exhibited significantly poorer performance in verbal fluency on the Controlled Oral Word Association Test FAS and in color naming on the Stroop Color and Word Test. In addition, the nonresponders tended to perform worse than the responders on the Stroop Color and Word Test reading subtest and the WAIS-III digit symbol subtest. Differential treatment response was specific to psychomotor speed because responders and nonresponders did not perform differently on tasks of executive functioning, attention, visuospatial functioning, or verbal intelligence. CONCLUSIONS: Psychomotor slowing may identify a subgroup of depressed patients who have a dopaminergic deficit that is unresponsive to fluoxetine monotherapy and who should therefore receive an alternative treatment.     

Cognitive executive function in dystonia.

Dystonia is a movement disorder considered to result from basal ganglia dysfunction. The aim of this study was to investigate the functional significance of frontal hyperactivity demonstrated in dystonia in imaging studies by examining executive function and working memory, in which the prefrontal cortex is known to be involved. We assessed 10 patients with idiopathic dystonia and 12 age- and IQ-matched normal controls. All subjects completed tests of first letter, category, and alternating category word fluency, the Wisconsin Card Sorting Test, the Stroop Colour Word Naming Test, the Missing Digit Test of working memory, a test of random number generation, a test requiring generation of self-ordered random number sequences, the Paced Serial Addition Test, a test of conditional associative learning, and finger tapping and peg insertion under unimanual, bimanual, and dual task conditions. The patients with dystonia did not differ significantly from controls on any measures of executive function or working memory used other than category word fluency and the extent of decline in tapping with one hand under dual task conditions when simultaneously inserting pegs with the other hand. For this small sample, the results suggest that unlike other movement disorders associated with fronto-striatal dysfunction such as Parkinson's disease or Huntington's disease, dystonia was not associated with deficits on the tests of executive function or working memory used. A more detailed investigation of cognitive function in a larger sample of patients is required.     

Mayo's Older Americans Normative Studies: Age- and IQ-Adjusted Norms for the Trail-Making Test, the Stroop Test, and MAE Controlled Oral Word Association Test

Although normative data sets for standardized neuropsychometric instruments often include adjustments for subject variables, there are reasons to believe that improvements in interpretive accuracy that result from such adjustments are less than optimal. In particular, years of formal education may be less closely related to test performances than is general intellectual functioning. In this second of four reanalyses of results from the Mayo Clinic's Older Americans Normative Studies (MOANS) databases, age-adjusted scores for the Trail-Making Test, the Stroop Color-Word Test, and the MAE Controlled Oral Word Associations Test were found to be more strongly associated with Mayo age-adjusted WAIS-R Full Scale IQ scores (rs=.368 to .495) than with education (rs=.174 to .367) for healthy older examinees between 56 and 99 years of age. For the TMT and the COWAT, but not the Stroop, these associations became stronger as IQ increased (cf. Dodrill, 1997, 1999). Tables of age- and IQ-adjusted percentile equivalents of MOANS age-adjusted TMT, Stroop, and COWAT scores are presented for eleven age ranges and seven IQ ranges.     

Tone duration mismatch negativity deficits predict impairment of executive function in schizophrenia

Impairment in mismatch negativity (MMN) potentials is a robust finding in schizophrenia. There are few studies which examined the correlation between MMN deficits and neuropsychological performances. The purpose of this study was to investigate the relationship between deficits of tone duration MMN and various neuropsychological measures in schizophrenic patients (n=23). The results demonstrated a significant correlation between low MMN amplitude and poor performances of executive function in Wisconsin Card Sorting Test, Stroop Test and Trail Making Test. Our finding suggests MMN deficits in schizophrenia predict deficits of executive function and might reflect ongoing functional abnormality of fronto-temporal interaction.