Department of Psychiatry, Psychotherapy and Psychosomatics, Rheinisch-Westfaelische Technische Hochschule (RWTH) Aachen University, D-52074 Aachen, Germany.
J Neurosci. 2012 Aug 15;32(33):11453-60. doi: 10.1523/JNEUROSCI.0678-12.2012.
Insights from both lesion and neuroimaging studies increasingly substantiate the view that the human cerebellum not only serves motor control but also supports various cognitive processes. Higher cognitive functions like working memory or executive control have been associated with the phylogenetically younger parts of the cerebellum, crus I and crus II. Functional connectivity studies corroborate this notion as activation of the cerebellum correlates with activity in numerous areas of the cerebral cortex. Moreover, these cerebrocerebellar loops were shown to be topographically organized. We used an attention-to-motion paradigm to elaborate on the effective connectivity of cerebellar crus I during visual attention. Psychophysiological interaction analyses demonstrated enhanced connectivity of the cerebellum--during attention--with dorsal visual stream regions including posterior parietal cortex (PPC) and left secondary visual cortex (V5). Dynamic causal modeling revealed a modulation of the connections from V5 to PPC and from crus I to V5 by attention. Remarkably, the influence which V5 exerted on PPC was reduced during attention, resulting in a suppression of the sensitivity of PPC to bottom-up information. Moreover, the sensitivity of V5 populations to inputs from crus I was increased under attention. This might underscore the presumed role of the cerebellum as a state estimator that provides hierarchically lower regions (V5) with top-down predictions, which in turn might be based on endogenous inputs from PPC to the cerebellum. These results are in line with formulations of attention in predictive coding, where attention increases the precision or sensitivity of hierarchically lower neuronal populations that may encode prediction error.
越来越多的病灶和神经影像学研究的结果证实了这样一种观点，即人类小脑不仅有助于运动控制，还支持各种认知过程。工作记忆或执行控制等较高的认知功能与小脑的进化较年轻的部分（小脑脚 I 和小脑脚 II）有关。功能连接研究证实了这一观点，因为小脑的激活与大脑皮层许多区域的活动相关。此外，这些脑-小脑循环被证明是具有拓扑组织的。我们使用注意到运动的范式来详细研究小脑脚 I 在视觉注意期间的有效连接。心理生理交互分析表明，在注意期间，小脑脚 I 与包括后顶叶皮层（PPC）和左侧次级视觉皮层（V5）在内的背侧视觉流区域的连接增强。动态因果建模揭示了注意力对 V5 到 PPC 和 V5 到小脑脚 I 的连接的调制。值得注意的是，在注意期间，V5 对 PPC 的影响降低，导致 PPC 对自上而下信息的敏感性降低。此外，在注意下，V5 群体对来自小脑脚 I 的输入的敏感性增加。这可能强调了小脑作为状态估计器的假定作用，它为层次较低的区域（V5）提供自上而下的预测，而这反过来又可能基于来自 PPC 到小脑的内源性输入。这些结果与预测编码中注意力的表述一致，其中注意力增加了可能编码预测误差的层次较低的神经元群体的精度或敏感性。
