Schmahmann Jeremy D, Killiany Ronald D, Vangel Mark, Moore Tara L, Moss Mark B, Rosene Douglas L
Ataxia Center, Division of Behavioral Neurology and Integrated Brain Medicine, Laboratory for Neuroanatomy and Cerebellar Neurobiology, Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, 02114, MA, USA.
Massachusetts General Hospital Ataxia Center, 101 Merrimac Street, Suite 310, Boston, 02114, MA, USA.
Sci Rep. 2025 Sep 17;15(1):32563. doi: 10.1038/s41598-025-17998-9.
The dysmetria of thought theory holds that the cerebellum is an integral node in the distributed neural circuits subserving cognition. We tested this theory in four rhesus monkeys with bilateral lesions in cerebellar dentate nuclei (DN), targeting ventral sectors linked with cerebral association cortices engaged in cognitive processing. Lesion localization was confirmed by MRI and histology. DN animals and controls were assessed for motor dexterity (Kuypers' Task), attention, three-choice discrimination, recognition memory (Delayed Non-Matching to Sample task [DNMS]), working memory (Delayed Recognition Span Task [DRST]) and executive function (Conceptual Set Shifting Task [CSST]). Performance by the DN animals was not significantly different than controls on the Kuypers' task and DNMS, but as a group they were impaired on DRST and CSST. DN monkeys achieved shorter spans on DRST. Their responses on CSST were more perseverative, and larger lesions produced greater deficits. This study provides the first empirical support for anatomical and functional MRI evidence of a motor-cognitive dichotomy in the cerebellar dentate nucleus. It highlights a within-cognition dichotomy in which cerebellum modulates dorsal stream cognitive functions (spatial awareness; dynamic actions of where and how) characterized by executive functions including working memory but is not engaged in ventral stream cognitive processes (static actions of object identification) exemplified by recognition memory.
思想辨距障碍理论认为，小脑是参与认知的分布式神经回路中不可或缺的节点。我们在四只恒河猴身上测试了这一理论，这些猴子的小脑齿状核（DN）存在双侧损伤，损伤部位为与参与认知加工的大脑联合皮质相连的腹侧区域。通过MRI和组织学检查确认了损伤定位。对DN动物和对照组进行了运动灵活性（凯珀斯任务）、注意力、三选辨别、识别记忆（延迟非匹配样本任务[DNMS]）、工作记忆（延迟识别跨度任务[DRST]）和执行功能（概念集转换任务[CSST]）的评估。在凯珀斯任务和DNMS上，DN动物的表现与对照组没有显著差异，但作为一个群体，它们在DRST和CSST上受损。DN猴子在DRST上的跨度较短。它们在CSST上的反应更具持续性，损伤越大，缺陷越明显。这项研究为小脑齿状核中运动-认知二分法的解剖学和功能MRI证据提供了首个实证支持。它突出了一种认知内二分法，即小脑调节以包括工作记忆在内的执行功能为特征的背侧流认知功能（空间意识；关于位置和方式的动态动作），但不参与以识别记忆为例的腹侧流认知过程（物体识别的静态动作）。
