Reaction time measures of sustained attention differentiate bipolar disorder from schizophrenia.

Although continuous performance tasks (CPTs) are becoming more common in psychiatric research, it remains unclear which performance measures best differentiate psychiatric patient groups and along which psychological dimensions. To address this the authors examined sustained attention decrements in patients with bipolar disorder and schizophrenia using CPT measures of perceptual sensitivity, response bias, and psychomotor processing speed. Patients with bipolar disorder with psychotic features (N=20), schizophrenia (N=20), and healthy controls (N=20) were evaluated using structured clinical interviews. These patients were rated with the Scale for the Assessment of Positive Symptoms and the Young Mania Rating Scale before completing a degraded-stimulus version of the CPT. Psychomotor processing speed was the only measure that reliably differentiated the groups across the entire vigilance period and was the strongest predictor of group membership. These findings suggest that reaction time measures may be sensitive to differences in the sustained attention abilities of patients with bipolar disorder and schizophrenia. By incorporating reaction time measures into CPT assessments, discriminant ability may be enhanced.     

Reaction time and sustained attention in schizophrenia and its genetic predisposition

Sustained attention is affected by schizophrenia. The simplest form of Continuous Performance Test (CPT-X) is a purer test of vigilance than more demanding variants but widely thought too insensitive to detect abnormalities in those with genetic predisposition to schizophrenia. We used a 7-minute CPT to compare 61 patients diagnosed with schizophrenia, 45 of their never-psychotic relatives, and 47 control subjects. We found a significant impairment in stimulus discrimination in both patients (p=0.001) and their relatives (p=0.006). There was no difference in stimulus discrimination between relatives of patients with impaired and unimpaired stimulus discrimination. Relatives of patients with unimpaired stimulus discrimination were still inferior to controls (p=0.02). Reactions slowed in all groups equally as the test progressed. Patients showed increased mean reaction time (p<0.0001) and interquartile range (p=0.003). Relatives showed slower reaction times (p=0.01) but normal interquartile range. Groups did not differ in respect of individuals' fastest reaction times. We conclude that genetic predisposition to schizophrenia reduces performance even during a task placing minimal cognitive load on working memory and perceptual processing, suggesting impaired vigilance. Increased reaction time in the disease and its predisposition appear to be due to changes in response distribution rather than by a limitation of maximum speed. Our results raise the possibility of separating the cognitive components of vigilance, working memory and perceptual processing tapped by more demanding variants of the CPT, and draw attention to the need for consideration of dynamic neurocognitive processes in schizophrenia.     

More severe sustained attention deficits in nonpsychotic siblings of multiplex schizophrenia families than in those of simplex ones

Sustained attention deficits measured by the Continuous Performance Test (CPT) have been proposed as an endophenotype of schizophrenia. However, little is known about whether sustained attention deficits in first-degree relatives of schizophrenic patients are associated with familial loading for schizophrenia. We examined 107 parents and 84 siblings of simplex schizophrenia families as well as 72 parents and 56 siblings of multiplex schizophrenia families, all nonpsychotic, using the Diagnostic Interview for Genetic Studies and two sessions of the CPT (undegraded and degraded). The effect of perceptual load was assessed using the residual of the regression of the degraded score on the undegraded one. Statistical models that can adjust for familial correlations were used to compare the CPT performance of relatives between the two types of families. Siblings from multiplex families exhibited worse performance on the degraded CPT and less proficiency in processing the perceptual load than those from simplex families. No such difference was observed for the parents on either CPT version. We concluded that sustained attention along with perceptual load processing is more impaired in the siblings of schizophrenic patients with high familial loading and that this finding might be useful for future genetic dissection of schizophrenia.     

Neurocognitive vulnerability, interpersonal criticism, and the emergence of unusual thinking by schizophrenic patients during family transactions

BACKGROUND: This study examined whether the combination of patients' neurocognitive deficits and criticism by others would predict the emergence of patients' unusual thinking during stressful family transactions. METHODS: When clinically stable, 41 patients with recent-onset schizophrenia completed 2 versions of a visual vigilance task, the Continuous Performance Test (CPT). One CPT emphasized early perceptual processing, while the other stressed immediate, working memory. On a separate occasion, patients and family members participated in a 20-minute interaction in which the number of relatives' criticisms and patients' unusual thoughts was assessed. RESULTS: In a hierarchical regression model, after entering performance on the CPT demanding immediate, working memory, and the number of criticisms by family members, the interaction of CPT performance and criticism significantly predicted the number of patients' unusual thoughts during the family session (r(2) change = 0.09; P =.03). Post hoc analyses revealed that the number of criticisms and odd thoughts correlated significantly (r = 0.59, P =. 03) for patients who had poor memory-load CPT performance, but were unrelated (r = -0.07) for patients who did well on the memory-load CPT. The CPT emphasizing early visual processing, either alone or in combination with interpersonal criticism, did not predict the number of patients' unusual thoughts during the interaction. CONCLUSION: The results suggest that the combination of patients' working memory deficits and interpersonal criticism jointly predicts psychotic thinking, consistent with a model of schizophrenia that emphasizes the interaction of neurocognitive vulnerability and psychosocial stress factors. Arch Gen Psychiatry. 2000;57:1174-1179.     

The Palau Early Psychosis Study: neurocognitive functioning in high-risk adolescents

ObjectiveThe purpose of the present study was to evaluate both the independent and joint effects of genetic risk and clinical status on neurocognitive functioning in adolescents from a population isolate with an elevated risk for schizophrenia and strong familial aggregation of cases.MethodThe subjects were 310 non-help seeking, drug-naïve adolescents 14–19 years of age from the Republic of Palau. The sample comprised 98 Genetically High Risk (GHR) adolescents, 54 of whom were symptomatic, and 212 Genetically Low Risk (GLR) adolescents, including 113 Clinically High Risk (CHR) subjects who were symptomatic and 99 normal controls who were non-symptomatic. Neurocognitive testing was conducted after the clinical assessment and included Wechsler Memory Scale tests of logical, visual and working memory, the perceptual organization and processing speed subtests of the WISC-III, CPT-IP measures of sustained attention, and tests of fine and gross neuromotor function.ResultsGHR adolescents showed impairments in immediate logical memory, verbal working memory, CPT-IP performance, and fine motor skills. The only two cognitive components influenced by the presence of early psychosis symptoms were WISC-III perceptual organization and spatial working memory. Neurocognitive deficits did not increase with increasing levels of psychopathology. We found no significant interactive effects of genetic risk and clinical status on neurocognitive functioning.ConclusionsGenetic risk and clinical status exert independent effects on neurocognitive function in HR adolescents, and genetic risk has a broader impact than clinical status. Our results suggest that many of the neurocognitive impairments associated with early psychosis are genetically mediated and can occur in genetically vulnerable individuals regardless of their clinical status. However, visuospatial processing appears to be uniquely disrupted by emerging symptomatology.     

Perceptual anomalies in schizophrenia: integrating phenomenology and cognitive neuroscience

From phenomenological and experimental perspectives, research in schizophrenia has emphasized deficits in "higher" cognitive functions, including attention, executive function, as well as memory. In contrast, general consensus has viewed dysfunctions in basic perceptual processes to be relatively unimportant in the explanation of more complex aspects of the disorder, including changes in self-experience and the development of symptoms such as delusions. We present evidence from phenomenology and cognitive neuroscience that changes in the perceptual field in schizophrenia may represent a core impairment. After introducing the phenomenological approach to perception (Husserl, the Gestalt School), we discuss the views of Paul Matussek, Klaus Conrad, Ludwig Binswanger, and Wolfgang Blankenburg on perception in schizophrenia. These 4 psychiatrists describe changes in perception and automatic processes that are related to the altered experience of self. The altered self-experience, in turn, may be responsible for the emergence of delusions. The phenomenological data are compatible with current research that conceptualizes dysfunctions in perceptual processing as a deficit in the ability to combine stimulus elements into coherent object representations. Relationships of deficits in perceptual organization to cognitive and social dysfunction as well as the possible neurobiological mechanisms are discussed.     

Comparison of the continuous performance test with and without working memory demands in healthy controls and patients with schizophrenia

The Penn Continuous Performance Test (PCPT), a measure of sustained visual attention developed for use in functional neuroimaging studies, was compared with a standard CPT developed by Gordon Diagnostic Systems (GDS; Vigilance subtest). The PCPT and the GDS CPT were administered with a standard neuropsychological battery to 68 healthy adults to assess reliability and construct validity. The test had adequate internal consistency, and convergent validity was established through significant correlations between measures of efficiency on the PCPT and the GDS CPT. With the exception of a significant correlation between efficiency measures on the GDS CPT and a measure of auditory sustained attention, neither version of the CPT correlated significantly with other measures in the battery. Factor analysis showed that the PCPT loaded with the GDS CPT. In 39 patients with schizophrenia and 39 matched, healthy controls, equivalent impairment was evident on the two CPT tasks. Neither version correlated significantly with symptom measurements. These results support previous conclusions that sustained visual attention in schizophrenia is a core information processing deficit, not directly related to symptomatology.     

Translocator protein (18 kDa) (TSPO) as a therapeutic target for anxiety and neurologic disorders

Earlier studies suggested more severe overall cognitive impairments in deficit versus non-deficit schizophrenia; however, the specific contribution of different cognitive domains to this overall cognitive impairment remains unclear. The purpose of this study was to compare the two subtypes in general cognitive functioning as well as in individual cognitive domains using the composite score approach. One hundred and forty-three patients fulfilling the criteria for the deficit syndrome were compared with 123 patients diagnosed with non-deficit schizophrenia. Neurocognitive functioning was assessed by a neuropsychological test battery measuring the domains of sustained vigilance/attention, working memory, short-term memory, verbal memory, cognitive flexibility, and ideation fluency. Using the raw neuropsychological measures, we calculated a global index of cognitive impairment and domain-specific composite z-scores. Association between these composite scores and the deficit syndrome was examined by logistic regression analysis. After adjusting for relevant covariates including sex, age, education, smoking, and antipsychotic dose, results indicated a significant increase in the likelihood of deficit syndrome as a function of global (OR = 5.40; 95% CI 3.02–9.65) as well as domain-specific impairments (OR > 2 for all individual domains except for short-term memory). Cognitive flexibility was an independent predictor (OR = 2.92; 95% CI 1.47–5.80), whereas other cognitive domains demonstrated no unique contribution to the general cognitive impairment. Patients with deficit schizophrenia suffer from a more severe degree of neurocognitive impairment, which is qualitatively similar to the dysfunction seen in non-deficit schizophrenia. However, our results indicate that cognitive flexibility is specifically impaired in deficit versus non-deficit patients and may therefore represent a core feature of this subtype.     

Neurocognitive endophenotypes in a multiplex multigenerational family study of schizophrenia

OBJECTIVE: Genetic factors contribute to the development of schizophrenia where cognitive dysfunction is a hallmark. The purpose of this article was to examine computerized neurocognitive measures as candidate endophenotypic markers of liability for schizophrenia in a genetically informative cohort. METHOD: European Americans from 35 multiplex multigenerational families (N=349) and healthy participants (N=154) underwent clinical assessments and neurocognitive measurements and provided blood samples. The neurocognitive measures included performance (accuracy and speed) from a computerized battery that assessed abstraction/mental flexibility; attention; verbal, face, and spatial memory; spatial processing; sensorimotor processing; and emotion intensity discrimination. RESULTS: Probands, relatives, and comparison subjects differed from each other in performance. Probands demonstrated greatest impairment relative to comparison subjects, followed by family members. Liability for schizophrenia affected the speed-accuracy tradeoff differently for specific neurocognitive domains. Significant heritability estimates were obtained for accuracy of verbal, facial, and spatial memory and spatial and emotion processing. For speed, estimates of heritability were significant for abstraction/mental flexibility, attention, face memory, and spatial and sensorimotor processing. CONCLUSIONS: In a multigenerational multiplex design, the authors demonstrated that neurocognitive measures are associated with schizophrenia, differentiate unaffected relatives from comparison subjects, and may have significant presumed heritability. Therefore, they are endophenotypes suitable for genetic studies. Accuracy and speed can be differentially sensitive to presumed genetic liability.     

Independence and overlap among neurocognitive correlates of community functioning in schizophrenia

Existing literature on the neurocognitive correlates of community functioning in schizophrenia has not adequately focused on the relationships among the correlated variables. In a sample of 40 outpatients with schizophrenia and related disorders, we studied two sets of variables that we expected to be related to broad ratings of community functioning: (1) the Wechsler Adult Intelligence Scale-III (WAIS-III) index scores for verbal comprehension, perceptual organization, working memory, and processing speed; and (2) positive, negative, disorganized and affective symptom variables. Of the WAIS-III index scores, working memory and processing speed entered a stepwise regression, together accounting for substantial variance in functional ratings (R(2)=0.37). However, only processing speed remained significantly associated with community functioning after controlling for the other indexes. In relation to community functioning, the remaining indexes appeared to be overlapping markers of general cognitive ability, rather than specific measures of discrete cognitive domains. Addition of positive and negative symptom variables in a further analysis greatly increased the explained functional variance (R(2)=0.65). Processing speed overlapped substantially with negative symptoms in predicting functioning, while the other WAIS-III indexes were independent of symptomatology. Results illustrate the importance of (1) knowing which neurocognitive variables have specific relationships to community functioning and which reflect the influence of more general cognitive ability in daily life, and (2) appreciating areas of overlap and independence among classes of correlates of functioning, such as neurocognitive and symptom variables. This improved understanding has implications for predictive models of community functioning, for cognitive rehabilitation and deficit compensation strategies, and for assessment practice.     

Intellectual functioning and memory deficits in schizophrenia

BACKGROUND: There is converging evidence about the existence of different subgroups of patients with schizophrenia in relation to intellectual ability (intelligence quotient [IQ]). Studying cognitive deficits in such patients in relation to IQ, and more specifically to memory, could help determine the patterns of preserved and impaired functioning in cognitive abilities in association with patterns of preserved and compromised intellect. This information could serve to delimit the possibilities of treatment and rehabilitation in those patients. METHODS: A total of 44 patients with schizophrenia completed a cognitive battery that included executive functioning, attention, speed of information processing, working memory, explicit memory, implicit memory, and everyday memory. Their IQ was also measured to identify 2 subgroups with an IQ of 85 as the cutoff point. Then, differences between the groups in the neurocognitive measures were studied. RESULTS: Performance in executive functioning, attention, working memory, and everyday memory, but not that in speed of information processing, explicit memory, and implicit memory, was associated with intellectual functioning. Patients performed at the same level in perceptual implicit memory but at a lower level in conceptual implicit memory as did healthy control subjects. DISCUSSION: Cognitive deficits in schizophrenia are associated with intellectual functioning. Implicit memory should not be considered as a unique entity. It is suggested that conceptual implicit memory deficit may be a core feature of schizophrenia.     

Self-efficacy and neurocognition may be related to coping responses in recent-onset schizophrenia

Although stressful life events can trigger psychotic and depressive symptom exacerbation in schizophrenia, many patients who experience stressful events do not subsequently relapse. Models of vulnerability, stress, and protective factors in schizophrenia suggest that effective coping responses may serve as protective factors. Coping behavior, in turn, may be influenced by a schizophrenia patient's level of self-efficacy and neurocognitive functioning. Using the Coping Responses Inventory, we examined how 29 recent-onset schizophrenia outpatients and 24 demographically matched normal comparison subjects responded to a negative interpersonal life event. Approach oriented coping responses, such as "Think of different ways to deal with the problem" and "Make a plan of action and follow it," were used significantly more often by normal subjects (M=2.27) than by schizophrenia patients (M=1.89; p < 0.02). Among schizophrenia patients, greater use of approach, problem-focused coping strategies was associated with high self-efficacy (r=0.55, p < 0.01) and better performance on a measure of sustained attention emphasizing perceptual processing (r=0.42, p < 0.05). Multiple regression indicated that self-efficacy and sustained attention accounted for 56% of the variance in the use of problem-focused coping, strategies by schizophrenia patients.     

Attention and executive functions profile in childhood absence epilepsy

Childhood absence epilepsy (CAE) has been associated with executive functions and attention deficits. To clarify the issue of neurocognitive impairments in CAE, we investigated whether specific executive functions and attention deficit patterns were present in a well-defined group of children with CAE who were taking valproic acid. Participants included 15 children with CAE and 15 healthy controls aged 8–15 years and matched for sex, age and IQ. We compared the performances of the two groups in the following neuropsychological domains: planning and problem solving (TOL), verbal fluency (FAS and CAT), verbal short-term memory (DSF), verbal working memory (DSB), visuospatial memory (Corsi Block Tapping Test) and sustained and divided attention (TMT-A and TMT-B). No differences were found between the two groups on measures of intellectual functioning, verbal short-term memory and visuospatial memory. By contrast, significant differences were found in total time of planning task, phonological and category fluency and sustained and divided attention. Future studies that systematically examine different aspects of attention and executive functions are needed to outline a clear and specific neuropsychological profile in CAE.     

How does the hippocampal formation mediate memory for stimuli processed by the magnocellular and parvocellular visual pathways? Evidence from the comparison of schizophrenia and amnestic mild cognitive impairment (aMCI)

Paired associates learning is impaired in both schizophrenia and amnestic mild cognitive impairment (aMCI), which may reflect hippocampal pathology. In addition, schizophrenia is characterized by the dysfunction of the retino-geniculo-striatal magnocellular (M) visual pathway. The purpose of this study was to investigate the interaction between visual perceptual and memory dysfunctions. We administered a modified version of the CANTAB paired associates learning task to patients with schizophrenia (n=20), aMCI (n=20), and two groups of matched healthy controls (n=20 for each patient group). The stimuli in the paired associates learning task biased information processing toward the M pathways (low contrast, low spatial frequency) and parvocellular (P) pathways (high contrast, high spatial frequency). Results revealed that patients with schizophrenia exhibited a more pronounced learning deficit for M-biased relative to P-biased stimuli. In aMCI, there were similar memory deficits for both types of stimuli. Orientation discrimination for M- and P-biased stimuli was intact in both groups of patients. The number of errors in the M-biased memory condition significantly and inversely correlated with the volume of the right hippocampus in schizophrenia. These results suggest an interaction between M-biased perceptual processing and short-term relational memory in schizophrenia, which may be associated with the structural alteration of the right hippocampus.     

Sustained attention in the context of emotional processing in patients with schizophrenia

Patients with schizophrenia show dysfunction in sustained attention and facial emotion processing. We investigated the interplay between sustained attention and emotion by presenting emotional faces as background during AX-CPT in patients with schizophrenia. Nineteen schizophrenia patients and 21 healthy control subjects participated. We presented AX-CPT number stimuli superimposed on the nose of background facial expressions (happy, neutral or sad) over three experimental blocks for each emotion. Signal detection sensitivity (A') and reaction time were measured. Patients showed a steeper sensitivity decline when happy faces (compared with sad faces) were presented as background stimuli. By contrast, controls' sensitivity was not affected by the background facial emotion stimuli. Across the emotion conditions, the decline of sensitivity over time was evident in patients, but not in controls. To our knowledge, the present study is the first to explore a change in sustained attention accompanied by simultaneous processing of emotional faces in schizophrenia patients. Our findings suggest that mechanisms underlying continuous performance test (CPT) performance decline over time and facial emotion deficit may interact with each other in patients with schizophrenia.     

Attention and executive functions profile in drug naive ADHD subtypes

Attention deficit hyperactivity disorder (ADHD) has been associated with executive functioning and sustained and divided attention deficits. In order to clarify the questions on neurocognitive impairment in ADHD, we investigated the presence of specific executive functions (EFs) and attention deficit patterns in ADHD clinical subtypes. 50 patients with ADHD and 44 controls were evaluated. All subjects were boys and performed a clinical-psychopathological and neuropsychological battery. Five main domains of EFs and attention were studied. Executive functions-related neurocognitive abilities were used as control tasks. ADHD patients, inattentive and combined subtypes differ from controls on response inhibition, divided attention, phonological, and visual object working memory and on variability of reaction times measured with CPT. Comparison of ADHD subtypes, in five main domains of EFs, did not show evidence of different executive functioning profiles. Response inhibition can predict performance on working memory tests but it cannot predict performance on divided attention/set shifting and on sustained attention. ADHD boys exhibit a selective impairment on executive functions and attention tasks. These data suggest the involvement of partially independent neural circuits which control inhibition and divided attention in ADHD. Since right prefrontal cortex seems to be crucial in controlling response inhibition, while left dorsolateral prefrontal cortex seems important in modulating divided attention, these areas are deputated to be involved in the pathogenesis of neuropsychological deficits in ADHD subtypes. In addition, this study candidates the impairment in phonological and visual-object working memory as a possible neuropsychological trait in ADHD males with inattentive or combined subtypes.     

Neurocognitive and symptom correlates of daily problem-solving skills in schizophrenia

Functional outcome for individuals with schizophrenia has been associated with cognitive impairment. Deficits in attention, memory, speed of information processing and problem-solving skills affect independent functioning, vocational performance, and interpersonal functioning. This study investigated the relationship between neurocognitive functioning, clinical symptoms and daily problem-solving skills in seriously and persistently ill persons. Thirty-eight inpatients and outpatients were administered a neurocognitive battery for attention, working memory, processing speed, perceptual organization, and executive functioning; and semi-structured clinical interviews using the BPRS and SANS. Estimates of daily problem-solving skills were obtained using the relevant factor subscale from the Independent Living Scales (ILS-PB). Daily problem-solving skills were significantly correlated with negative symptoms, processing speed, verbal memory, and working memory scores. A regression model using an enter method suggests that working memory and negative symptoms are significant predictors of daily problem-solving skills and account for 73.2% of the variance. Further analyses demonstrate that daily problem-solving skills and negative symptoms were significantly different for inpatients and outpatients and significantly correlated with community status. The findings suggest the ILS-PB has utility as a proxy measure for assessing real-world functioning in schizophrenia.     

Organizational and Visual Memory Deficits in Schizophrenia and Bipolar Psychoses Using the Rey-Osterrieth Complex Figure: Effects of Duration of Illness

Verbal declarative memory deficits in schizophrenia are well documented whereas visual declarative memory is less studied. Moreover, there are limited data on whether organizational and visual memory deficits are specific to schizophrenic psychoses. We compared visual memory and organizational function in patients with chronic schizophrenia (n = 79) and chronic bipolar psychotic disorder (n = 14), and in healthy controls (n = 84) using the Rey-Osterrieth Complex Figure (ROCF), testing whether organizational impairments (i.e., executive dysfunctions) account for the visual memory deficit. Groups were comparable on age, handedness and expected intellectual ability (based on single word reading). Using analyses of covariance with sex, parental SES and ethnicity as co-variates, patients with schizophrenia were significantly more impaired than controls on copy accuracy, on recall accuracy, and on percent accuracy of recall. Patients with schizophrenia used a more detail-oriented style on copy and recall and had significantly worse recognition memory. After co-varying IQ, copy organization was also significantly different between the groups. Results for accuracy of copy and recall were not significantly attenuated when controlling for copy organization. Duration of illness was associated with visual memory. Bipolar patients performed at an intermediate level between controls and patients with schizophrenia. The data suggest that in schizophrenia, patients have a visual memory disorder characterized by both organizational processing impairments and retention difficulties, and that there is a decline in visual memory functions with duration of illness. Further research is required to determine whether similar mechanisms underlie the neurocognitive deficits in these psychotic disorders.     

Psychophysiological correlates of social skills deficits in persons with schizophrenia

Social skill deficits in schizophrenia profoundly affect patients' life-long outcome, although the profile of the underlying cognitive dysfunction still remains a matter of debate. In the present study, we investigated the relationship between social skills and event-related potentials (ERPs) in an auditory selective attention task, in addition to the neurocognitive indices obtained from the degraded-stimulus continuous performance test (CPT) and clinical indices, such as Brief Psychiatric Rating Scale (BRPS) and global assessment of function (GAF) scores. Social skills were assessed using a Japanese version of the structured role play test. Fourteen persons with schizophrenia participated in the study. Non-verbal skills showed a positive correlation with GAF, the performance level, N1 and N2b amplitude in the ERP task, and hit rate in the CPT, and a negative correlation with reaction time in the CPT. Verbal communication skills showed a positive correlation with GAF, the performance level and N2b amplitude in the ERP task, and hit rate in the CPT, and a negative correlation with reaction time in the CPT. Processing skills showed a positive correlation with the performance level and N1 amplitude in the ERP task and a negative correlation with reaction time in the CPT. These findings suggested that the social skill deficits of persons with schizophrenia were related to the vigilance level and controlled stimulus detection processing.     

Psychophysiological correlates of social skills deficits in persons with schizophrenia

Social skill deficits in schizophrenia profoundly affect patients’ life-long outcome, although the profile of the underlying cognitive dysfunction still remains a matter of debate. In the present study, we investigated the relationship between social skills and event-related potentials (ERPs) in an auditory selective attention task, in addition to the neurocognitive indices obtained from the degraded-stimulus continuous performance test (CPT) and clinical indices, such as Brief Psychiatric Rating Scale (BRPS) and global assessment of function (GAF) scores. Social skills were assessed using a Japanese version of the structured role play test. Fourteen persons with schizophrenia participated in the study. Non-verbal skills showed a positive correlation with GAF, the performance level, N1 and N2b amplitude in the ERP task, and hit rate in the CPT, and a negative correlation with reaction time in the CPT. Verbal communication skills showed a positive correlation with GAF, the performance level and N2b amplitude in the ERP task, and hit rate in the CPT, and a negative correlation with reaction time in the CPT. Processing skills showed a positive correlation with the performance level and N1 amplitude in the ERP task and a negative correlation with reaction time in the CPT. These findings suggested that the social skill deficits of persons with schizophrenia were related to the vigilance level and controlled stimulus detection processing.