Department of Human Neurosciences, Sapienza University of Rome, Viale dell'Università 30, 00185, Rome, Italy.
Department of Medical-Surgical Sciences and Biotechnologies, A. Fiorini Hospital, Terracina, LT, Italy.
Cerebellum. 2019 Jun;18(3):457-468. doi: 10.1007/s12311-019-01014-8.
The functional domain of the cerebellum extends beyond its traditional role in motor control. In recent years, this structure has increasingly been considered to play a crucial role even in cognitive performance and attentional processes. Attention is defined as the ability to appropriately allocate processing resources to relevant stimuli. According to the Posnerian model, three interacting networks modulate attentive processes: the alerting, orienting, and executive networks. The aim of this study was to investigate the role played by the cerebellum in the functioning of the attentive networks using the Attention Network Test (ANT). We studied the effects of transcranial direct current stimulation (tDCS), delivered over the cerebellum in cathodal, anodal, and sham sessions, on ANT parameters in healthy subjects. After anodal and sham tDCS, the efficiency of the three attention networks remained stable, and a significant reduction in reaction time (RT) following the task repetition was observed for both congruent and incongruent targets, indicating a learning effect. After cathodal stimulation, instead, while the efficiency of the alerting and orienting networks remained stable, the efficiency of the executive network was significantly reduced. Moreover, a significant reduction in RT was observed for the congruent target alone, with no difference being detected for the incongruent target, indicating that cerebellar inhibition caused an attentive executive dysfunction specifically related to the ability to process complex stimuli in which conflict signals or errors are present. These results point to a role of the cerebellum, a subcortical structure that is thought to affect error processing both directly, by making predictions of errors or behaviors related to errors, and indirectly, by managing the functioning of brain cortical areas involved in the perception of conflicting signals, in the functioning of the attentional networks, particularly the executive network.
小脑的功能域超出了其在运动控制中的传统作用。近年来，越来越多的人认为小脑在认知表现和注意力过程中起着至关重要的作用。注意力被定义为将处理资源适当地分配给相关刺激的能力。根据 Posner 模型，三个相互作用的网络调节注意过程：警觉、定向和执行网络。本研究旨在使用注意网络测试（ANT）研究小脑在注意网络功能中的作用。我们研究了经颅直流电刺激（tDCS）在小脑上的阴极、阳极和假刺激对健康受试者 ANT 参数的影响。在阳极和假刺激后，三个注意网络的效率保持稳定，并且在任务重复后观察到一致和不一致目标的反应时间（RT）显著减少，表明存在学习效应。相反，在阴极刺激后，警觉和定向网络的效率保持稳定，而执行网络的效率显著降低。此外，仅一致目标的 RT 显著减少，而不一致目标的 RT 没有差异，表明小脑抑制导致与处理存在冲突信号或错误的复杂刺激相关的注意力执行功能障碍。这些结果表明小脑在注意力网络的功能中起着作用，小脑是一种认为直接影响错误处理的皮质下结构，通过预测错误或与错误相关的行为，以及间接通过管理涉及冲突信号感知的大脑皮质区域的功能，在注意力网络的功能中起着作用，特别是执行网络。
