The ability to rapidly stop or change a planned action is a critical cognitive process that is impaired in schizophrenia. The current study aimed to examine whether this impairment reflects familial vulnerability to schizophrenia across two experiments comparing unaffected first-degree relatives to healthy controls. First, we examined performance on a saccadic stop-signal task that required rapid inhibition of an eye movement. Then, in a different sample, we investigated behavioral and neural responses (using fMRI) during a stop-signal task variant that required rapid modification of a prepared eye movement. Here, we examined differences between relatives and healthy controls in terms of activation and effective connectivity within an oculomotor control network during task performance. Like individuals with schizophrenia, the unaffected relatives showed behavioral evidence for more inefficient inhibitory processes. Unlike previous findings in individuals with schizophrenia, however, the relatives showed evidence for a compensatory waiting strategy. Behavioral differences were accompanied by more activation among the relatives in task-relevant regions across conditions and group differences in effective connectivity across the task that were modulated differently by the instruction to exert control over a planned saccade. Effective connectivity parameters were related to behavioral measures of inhibition efficiency. The results suggest that individuals at familial risk for schizophrenia were engaging an oculomotor control network differently than controls and in a way that compromises inhibition efficiency.

中文翻译：

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精神分裂症患者未受影响的亲属眼球运动控制网络内的有效连接发生改变

快速停止或改变计划行动的能力是精神分裂症中受损的关键认知过程。目前的研究旨在通过两个比较未受影响的一级亲属与健康对照的实验来检查这种损害是否反映了家族对精神分裂症的脆弱性。首先，我们检查了需要快速抑制眼球运动的扫视停止信号任务的表现。然后，在另一个样本中，我们研究了停止信号任务变体期间的行为和神经反应（使用 fMRI），该变体需要快速修改准备好的眼球运动。在这里，我们检查了亲属和健康对照组在任务执行期间在动眼神经控制网络内的激活和有效连接方面的差异。就像精神分裂症患者一样，未受影响的亲属表现出更低效的抑制过程的行为证据。然而，与之前对精神分裂症患者的研究结果不同，这些亲属显示了补偿性等待策略的证据。行为差异伴随着跨条件任务相关区域的亲属之间的更多激活，以及跨任务的有效连接的群体差异，这些差异通过对计划的扫视施加控制的指令进行不同调制。有效连接参数与抑制效率的行为测量有关。结果表明，具有精神分裂症家族风险的个体参与动眼神经控制网络的方式与对照组不同，并且以损害抑制效率的方式进行。