Department of Psychiatry, University of California, San Diego, 9500 Gilman Drive, MC 0603V, La Jolla, CA 92093-0603, USA.
Schizophr Bull. 2012 Jun;38(4):760-8. doi: 10.1093/schbul/sbq149. Epub 2010 Dec 16.
The nature of executive dysfunction in schizophrenia is nebulous, due to inconsistencies in conceptualizing and operationalizing the construct, and the broader question of whether schizophrenia is best characterized in terms of specific vs generalized cognitive deficits. The current study aimed to determine whether executive functions represent unitary vs diverse constructs in schizophrenia.
Participants included 145 community-dwelling individuals with schizophrenia. Executive functions were measured with the Delis-Kaplan Executive Functioning System (D-KEFS). We conducted an exploratory factor analysis (EFA) with principal axis factoring, as well as parallel analyses to examine the latent constructs underlying the D-KEFS tasks, a second EFA on weighted residuals of the D-KEFS tasks (after accounting for processing speed measured with the Digit Symbol task), and bivariate correlations to examine relationships between the D-KEFS components and relevant demographic and clinical variables, crystallized verbal knowledge, and functional capacity.
EFA of the D-KEFS tasks yielded 2 factors (cognitive flexibility/timed tests and abstraction). EFA of the processing speed-weighted D-KEFS residuals also yielded 2 factors (cognitive flexibility and abstraction). Cognitive flexibility was negatively correlated with psychopathology. Better abstraction was associated with higher education, shorter illness duration, and better functional capacity. Both factors were positively correlated with crystallized verbal knowledge.
Executive functions in schizophrenia could be parsed into 2 partially related but separable subconstructs. Future efforts to elucidate functional outcomes as well as neurobiological underpinnings of schizophrenia may be facilitated by attending to the distinction between cognitive flexibility and abstraction.
精神分裂症执行功能的本质是模糊的，这是由于概念化和操作化结构的不一致，以及精神分裂症是否最好用特定的还是广泛的认知缺陷来描述的更广泛的问题。本研究旨在确定执行功能在精神分裂症中是否代表单一的还是多样化的结构。
参与者包括 145 名居住在社区的精神分裂症患者。使用 Delis-Kaplan 执行功能系统（D-KEFS）测量执行功能。我们进行了探索性因素分析（EFA），采用主轴因子分析，以及并行分析，以检查 D-KEFS 任务的潜在结构，对 D-KEFS 任务的加权残差进行第二次 EFA（在考虑到数字符号任务测量的处理速度后），以及双变量相关性分析，以检查 D-KEFS 成分与相关人口统计学和临床变量、晶体语言知识和功能能力之间的关系。
D-KEFS 任务的 EFA 产生了 2 个因素（认知灵活性/定时测试和抽象）。处理速度加权 D-KEFS 残差的 EFA 也产生了 2 个因素（认知灵活性和抽象）。认知灵活性与精神病理学呈负相关。更好的抽象与更高的教育水平、更短的疾病持续时间和更好的功能能力相关。这两个因素都与晶体语言知识呈正相关。
精神分裂症的执行功能可以被分解为 2 个部分相关但可分离的子结构。未来，通过关注认知灵活性和抽象之间的区别，阐明精神分裂症的功能结果和神经生物学基础的努力可能会得到促进。
