Understanding the executive functioning heterogeneity in schizophrenia

Schizophrenia is characterized by heterogeneous brain abnormalities involving cerebral regions implied in the executive functioning. The dysexecutive syndrome is one of the most prominent and functionally cognitive features of schizophrenia. Nevertheless, it is not clear to what extend executive deficits are heterogeneous in schizophrenia patients. Furthermore, it is still unknown if the executive impairments observed in schizophrenia are better characterized as specific or as reflecting generalized cognitive factors. The four executive processes (i.e. updating, inhibition, shifting and divided attention) described in Miyake et al.'s (2000) theoretical model were examined in 62 individuals with schizophrenia and 49 healthy controls. At group level, impairments in all four executive processes confirmed the marked impairment in executive functioning in patients with schizophrenia. Statistical analysis indicated that executive performances in schizophrenia patients were more heterogeneous than in healthy controls. Compared with standardized norms, 94% of patients exhibited impairment in at least one of the executive tasks. Twenty-one percent of patients exhibited impairment in one executive task, 27% in two tasks, 23% in three executive tasks and 23% exhibited impairments in the four executive tasks. Six percent of patients had normal executive profile. Regression analysis indicated that only premorbid intellectual quotient and a general slowing in processing speed predicted the executive dysfunction severity. Executive functioning was not affected by age, duration of illness, psychotic status, or by antipsychotic dosage. Our results emphasize the heterogeneity of the dysexecutive syndrome in schizophrenia when individual profile analysis is considered, and extend the view that individual cognitive differences in schizophrenia are largely underlined by general cognitive factors such as intellectual level and general processing speed.     

论全球性法律的同构与异质

在当今全球化趋势日益发展的宏观背景下 ,全球法律生活也必然表现出同构与异质的辩证统一特征。这种同构的根源在于全球共同的人性基础、市场经济的普遍确立、法律发展的一般规律以及跨国公司和国际组织的迅猛发展 ,并表现在法律原则、法律规则和法律适用机制等多重层面。但由于各国的文化传统、政治体制和经济结构等因素的千差万别 ,全球法律生活也呈现出五彩缤纷的复杂画面。     

Eye-tracking dysfunction and birth-month weather in schizophrenia.

The prevalence of eye-tracking dysfunction (ETD) is significantly elevated in individuals with a diagnosis of schizophrenia and in their nonschizophrenic relatives, suggesting that ETD marks a familial (most likely genetic) risk factor for schizophrenia. Birth in a season with intemperate weather is also a widely reported risk factor for schizophrenia and is particularly marked for the subgroup with no family history of the disorder. This study examined how these two risk factors covaried in 78 patients with a Diagnostic and Statistical Manual of Mental Disorders (3rd ed., rev.; American Psychiatric Association, 1987) diagnosis of schizophrenia. Eye tracking and birth-month weather were independently assessed. As hypothesized, patients without ETD were significantly more likely to be born in months with intemperate weather (both hot and cold) than either patients with ETD or people in the general population. Etiologic factors associated with severe weather near birth may be important sources of nonfamilial schizophrenia.     

Emotional experience and expression in schizophrenia and depression.

The emotional responses of schizophrenic, depressed, and normal subjects and whether differences in the emotional responding of these groups depended on how emotional responses were elicited or measured were examined. Twenty-three blunted and 20 nonblunted schizophrenics, 17 unipolar depressed subjects, and 20 normal subjects were exposed to a series of affect-eliciting stimuli. The stimuli varied in valence (positive vs. negative) and in level of cognitive demand. Subjects reported their subjective experiences, and their facial expressions were videotaped. Blunted schizophrenics were the least facially expressive, although their reported subjective experiences did not differ from those of the other groups. The nonblunted schizophrenics were more responsive than the depressed subjects to the positive stimuli, although the two groups did not differ in their clinical ratings of affective flatness.     

Personality Homogeneity in Organizations and Occupations: Considering Similarity Sources

Purpose

The purpose of this study was to investigate organizational and occupational homogeneity, compare homogeneity at different levels of composition, and uncover a mechanism for homogeneity.

Design/Methodology/Approach

Data were obtained from an archival data base of current employees (N = 23,933) in 40 organizations, 19 major job groupings, 42 minor job groupings, and 115 detailed job titles.

Findings

Support for homogeneity within organizations and occupations was found, regardless of the granularity with which occupation were defined. Homogeneity estimates were smaller than prior estimates in the literature based on smaller, less diverse samples. Occupational homogeneity was significantly greater than homogeneity at the organizational level for neuroticism and extraversion. As a potential mechanism, we demonstrated that occupational interest could predict personality at the occupational level.

Implications

Investigating homogeneity effects with a large, representative sample and simultaneously considering occupation and organization helps to advance our theoretical understanding of the Attraction–Selection–Attrition process. This study provides evidence of relative homogeneity effects and mechanisms. Such knowledge could help inform the selection, training, and socialization tactics employed by practitioners.

Originality/Value

Little is currently known about how within-occupation homogeneity in personality relates to within-organization homogeneity, or the influence of vocational interests on such homogeneity. We provide a methodological update to decompose and compare organizational and occupational influence on personality homogeneity. We also assess homogeneity at three levels of occupational granularity, and delineate a mechanism for personality to become homogeneous at the occupation level.

     

测验同质性系数及其区间估计

在决定将多维测验分数合并成测验总分时, 应当考虑测验同质性。如果同质性太低, 合成总分没有什么意义。同质性高低可以用同质性系数来衡量。用来计算同质性系数的模型是近年来受到关注的双因子模型(既有全局因子又有局部因子), 测验的同质性系数定义为测验分数方差中全局因子分数方差所占的比例。本文用Delta法推导出计算同质性系数的标准误公式, 进而计算其置信区间。提供了简单的计算同质性系数及其置信区间的程序。用一个例子说明如何估计同质性系数及其置信区间, 通过模拟比较了用Delta法和用Bootstrap法计算的置信区间, 发现两者差异很小。     

Forms of memory failure in schizophrenia.

Effortful and automatic memory task performances were examined in 36 schizophrenic patients and 18 normal control Ss. Tasks included free recall, recognition, and frequency estimation. Patients demonstrated impairment in recall, in recognition, in semantic encoding, and in frequency estimation. Deficits were observed across tasks despite differences in attentional demands. The results suggest a basic compromise of memory function, which is consistent with recent neuroimaging evidence of structural or physiological abnormalities in frontal and temporal lobe structures in schizophrenia.     

Mentalising, schizotypy, and schizophrenia.

Despite accumulating evidence that patients with schizophrenia perform poorly in mentalising tasks, doubts remain about the primacy of the role played by defective mentalising in schizophrenia. This study investigated the relationship between mentalising ability and self-reported schizotypal traits in non-clinical adults who reported no history of psychiatric illness in order to test two counter-proposals: (1) defective mentalising is a primary cause of psychotic symptoms in schizophrenia; and (2) defective mentalising in schizophrenia is a secondary consequence of the chronic asociality that is typical of general psychiatric illness. Mentalising ability was tested using a false-belief picture sequencing task that has been used elsewhere to demonstrate poor mentalising in patients with schizophrenia. Evidence of selective mentalising deficits in high schizotypal non-clinical subjects discounted the view that defective mentalising is restricted to psychiatric illness and strengthened the case for continuity models of psychosis-proneness. Furthermore, evidence that poor mentalisers in the normal population are more likely to self-report psychotic-like traits, as well as asocial or idiosyncratic behaviours, refuted suggestions that defective mentalising is linked solely to asocial symptomatology and supported the view that defective mentalising may have a fundamental role to play in the explanation of psychotic symptoms. In order to specify what that role might be, alternative theoretical accounts of defective mentalising were tested. Neither executive planning deficits nor failure to inhibit cognitively salient inappropriate information could adequately explain the pattern of selective mentalising deficits found in high schizotypal non-clinical subjects. Our findings suggest that there exists a domain-specific cognitive module that is dedicated to inferring and representing mental states which, when dysfunctional, causes defective mentalising that manifests phenomenologically in psychotic-like traits and impoverished social awareness of variable expression and ranging severity.