Lehet Matthew, Tso Ivy F, Park Sohee, Neggers Sebastiaan F W, Thompson Ilse A, Kahn Rene S, Thakkar Katharine N
Department of Psychology, Michigan State University, East Lansing, MI 48824, USA.
Department of Psychiatry, University of Michigan, Ann Arbor, MI 48109, USA.
Brain Sci. 2021 Sep 17;11(9):1228. doi: 10.3390/brainsci11091228.
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.
迅速停止或改变计划行动的能力是一种关键的认知过程，在精神分裂症中会受到损害。当前的研究旨在通过两项实验来检验这种损害是否反映了精神分裂症的家族易感性，这两项实验将未患病的一级亲属与健康对照进行了比较。首先，我们考察了在一项扫视停止信号任务中的表现，该任务要求快速抑制眼球运动。然后，在另一个样本中，我们研究了在一项停止信号任务变体中（使用功能磁共振成像）的行为和神经反应，该变体要求对准备好的眼球运动进行快速调整。在这里，我们考察了亲属和健康对照在任务执行期间动眼控制网络内激活和有效连接方面的差异。与精神分裂症患者一样，未患病的亲属也表现出抑制过程效率较低的行为证据。然而，与之前对精神分裂症患者的研究结果不同，亲属表现出一种补偿性等待策略的证据。行为差异伴随着亲属在不同条件下任务相关区域的更多激活，以及任务中有效连接的组间差异，这些差异因对计划扫视施加控制的指令而受到不同调节。有效连接参数与抑制效率的行为指标相关。结果表明，有精神分裂症家族风险的个体与对照组在动眼控制网络的参与方式上有所不同，且这种方式损害了抑制效率。
