Smooth pursuit eye movements (SPEM) hold the image of a slowly moving stimulus on the fovea. The neural system underlying SPEM primarily includes visual, parietal and frontal areas. In the present study, we investigated how these areas are functionally coupled and how these couplings are influenced by target motion frequency. To this end, healthy participants (N=57) were instructed to follow a sinusoidal target stimulus moving horizontally at two different frequencies (0.2 Hz, 0.4 Hz). Eye movements and BOLD activity were recorded simultaneously. Functional connectivity of the key areas of the SPEM network was investigated using a Psychophysiological Interaction (PPI) approach. It was analyzed how activity in five eye movement related seed regions (lateral geniculate nucleus, V1, V5, posterior parietal cortex, frontal eye fields) relates to activity in other parts of the brain during SPEM. The behavioral results showed clear deterioration of SPEM performance at higher target frequency. BOLD activity during SPEM vs. fixation occurred in a geniculo-occipito-parieto-frontal network, replicating previous findings. PPI analysis yielded wide-spread, partially overlapping networks. Especially frontal eye fields and posterior parietal cortex showed task-dependent connectivity to large parts of the entire cortex, while other seed regions demonstrated more regionally focused connectivity. Higher target frequency was associated with stronger activations in visual areas but had no effect on functional connectivity. In summary, the results confirm and extend previous knowledge regarding the neural mechanisms underlying SPEM and provide a valuable basis for further investigations such as in patients with SPEM impairments and known alterations in brain connectivity.

中文翻译：

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平滑追踪眼球运动期间的功能连接

平滑追踪眼球运动 (SPEM) 在中央凹上保持缓慢移动刺激的图像。SPEM 的神经系统主要包括视觉、顶叶和额叶区域。在本研究中，我们调查了这些区域如何在功能上耦合以及这些耦合如何受目标运动频率的影响。为此，健康参与者 (N=57) 被指示遵循以两种不同频率 (0.2 Hz、0.4 Hz) 水平移动的正弦目标刺激。同时记录眼球运动和 BOLD 活动。使用心理生理交互 (PPI) 方法研究了 SPEM 网络关键区域的功能连接。分析了五个眼球运动相关种子区域（外侧膝状核、V1、V5、后顶叶皮层、额叶视野）与 SPEM 期间大脑其他部分的活动有关。行为结果表明，在更高的目标频率下，SPEM 性能明显恶化。SPEM 与固定期间的 BOLD 活动发生在膝-枕-顶-额叶网络中，复制了以前的发现。PPI 分析产生了广泛的、部分重叠的网络。尤其是额叶眼区和后顶叶皮层表现出与整个皮层大部分区域的任务相关性连接，而其他种子区域则表现出更多区域性的连接性。更高的目标频率与视觉区域的更强激活相关，但对功能连接没有影响。总之，