Department of Neuroscience, University of Georgia, Athens, Georgia, USA.
Department of Psychology, University of Georgia, Athens, Georgia, USA.
Psychophysiology. 2017 Dec;54(12):1967-1977. doi: 10.1111/psyp.12969. Epub 2017 Aug 23.
Recent diffusion tensor imaging (DTI) studies suggest that altered white matter fiber integrity is a pathophysiological feature of schizophrenia. Lower white matter integrity is associated with poor cognitive control, a characteristic of schizophrenia that can be measured using antisaccade tasks. Although the functional neural correlates of poor antisaccade performance have been well documented, fewer studies have investigated the extent to which white matter fibers connecting the functional nodes of this network contribute to antisaccade performance. The aim of the present study was to assess the white matter structural integrity of fibers connecting two functional nodes (putamen and medial frontal eye fields) of the saccadic eye movement network implicated in poor antisaccade performance in schizophrenia. To evaluate white matter integrity, DTI was acquired on subjects with schizophrenia and two comparison groups: (a) behaviorally matched healthy comparison subjects with low levels of cognitive control (LCC group), and (b) healthy subjects with high levels of cognitive control (HCC group). White matter fibers were tracked between functional regions of interest generated from antisaccade fMRI activation maps, and measures of diffusivity were quantified. The results demonstrated lower white matter integrity in the schizophrenia group than in the HCC group, but not the LCC group who showed similarly poor cognitive control performance. Overall, the results suggest that these alterations are not specific to the disease process of schizophrenia, but may rather be a function of uncontrolled cognitive factors that are concomitant with the disease but also observed in some healthy people.
最近的弥散张量成像（DTI）研究表明，白质纤维完整性的改变是精神分裂症的一种病理生理特征。较低的白质完整性与较差的认知控制有关，认知控制是精神分裂症的一个特征，可以通过反扫视任务来测量。尽管反扫视表现不佳的功能神经相关性已经得到了很好的记录，但较少的研究调查了连接该网络功能节点的白质纤维在多大程度上对反扫视表现有贡献。本研究的目的是评估与反扫视表现不佳有关的两个功能节点（壳核和内侧额眼区）之间的连接白质纤维的结构完整性。为了评估白质完整性，对精神分裂症患者和两个对照组（a）行为匹配的认知控制水平较低的健康对照组（LCC 组），以及（b）认知控制水平较高的健康对照组（HCC 组）进行了 DTI 采集。在反扫视 fMRI 激活图生成的功能感兴趣区之间追踪白质纤维，并量化扩散度测量值。结果表明，精神分裂症组的白质完整性低于 HCC 组，但与认知控制表现同样较差的 LCC 组无差异。总体而言，结果表明这些改变不是精神分裂症疾病过程特有的，而是可能是与疾病同时存在但也在一些健康人群中观察到的不受控制的认知因素的功能。
