Neural circuitry plasticity resulting from saccadic practice in schizophrenia

描述（由申请人提供）：了解大脑如何因使用而发生变化，对研究人员研究从学习新技能到创伤性脑损伤后功能恢复等各种主题具有重要意义。对一项任务的体验可能会导致表现和潜在神经回路的变化。像其他运动任务一样，扫视任务是可塑性的，并受到练习的影响。练习反扫视（朝向周围刺激的镜像扫视）导致反扫视错误的减少。相比之下，练习亲眼跳（朝向外围刺激的扫视）可能会导致反眼跳任务中方向错误数量的增加（Dyckman & McDowell，2005）。这些行为变化提供了一个模板，用于确定如何支持亲和反眼跳性能的神经通路可以随着时间的推移进行修改。前额叶皮层在介导抗扫视表现中的假定作用，以及精神分裂症受试者中记录的前额叶功能减退和抗扫视表现不佳，表明精神分裂症受试者中操纵抗扫视表现可能特别有用。本研究的总体目标是了解正常人和精神分裂症患者的神经可塑性。本研究中的受试者将参加为期两周的试验。将在3个时间点在fMRI环境中测试支持和抗扫视性能：1）测试前，2）测试中，和3）测试后。在测试阶段之间，受试者将每天（8个时间点）访问眼动实验室以练习正面或反扫视任务。据推测，正常和精神分裂症受试者将提高反眼跳的性能后，练习反眼跳。神经回路随时间的变化在两组之间会有所不同。最初，精神分裂症受试者与正常受试者相比，将显示出降低的抗扫视相关的前额叶皮层活动。在练习之后，精神分裂症受试者中的抗扫视改善将伴随着前额叶皮层活动的增加。然而，正常受试者会表现出与练习相关的前额叶皮层活动减少，因为反扫视变得更加自动化，执行起来不那么费力。精神分裂症受试者的大脑不同于正常受试者的大脑在他们的实践反应的方式可能有重要的意义，了解的持久性和机制，支持功能康复在这一组。

DESCRIPTION (provided by applicant): Understanding how the brain changes as a result of use has implications for researchers studying topics as diverse as learning a new skill, to functional recovery following traumatic brain injury. Experience with a task can lead to changes in performance and in the underlying neural circuitry. Like other motor tasks, saccadic tasks are malleable and are affected by practice. Practicing anti-saccades (glances toward the mirror image of a peripheral stimulus) results in a decrease of anti-saccade errors. In contrast, practicing pro-saccades (glances toward a peripheral stimulus) can result in an increase in the number of direction errors on the anti-saccade task (Dyckman & McDowell, 2005). These behavioral changes provide a template for determining how neural pathways supporting pro- and anti-saccade performance may be modified across time. The putative role of prefrontal cortex in mediating anti-saccade performance, as well as the documented hypofrontality and poor anti-saccade performance among schizophrenia subjects, suggests that manipulating anti-saccade performance in subjects with schizophrenia may be particularly informative. The overall aim of this research proposal is to understand practice-based neural plasticity among normal and schizophrenia subjects. Subjects in this study will take part in a two-week trial. Pro- and anti-saccade performance will be tested in the fMRI environment at 3 time points: 1) Pre-Test, 2) Mid-Test, and 3) Post- Test. Between the test sessions, subjects will visit the eye movement laboratory daily (8 time points) to practice either pro- or anti-saccade tasks. It is hypothesized that both normal and schizophrenia subjects will improve on anti-saccade performance after practicing anti-saccades. Changes in neural circuitry across time will differ between the two groups. Initially schizophrenia subjects will show decreased anti-saccade associated prefrontal cortex activity compared to normal subjects. After practice, anti-saccade improvement among the schizophrenia subjects will be accompanied by an increase in prefrontal cortex activity. Normal subjects, however, will show a practice-related decrease in prefrontal cortex activity as the anti-saccades become more automatic and less effortful to perform. The manner in which schizophrenia subjects' brains differ from normal subjects' brains in their response to practice may have important implications for understanding the durability of and mechanisms supporting functional rehabilitation within this group.