PDF(Pubmed)
Abstract：
Previous studies have shown that the left hemisphere dominates motor function, often observed through homotopic activation measurements. Using a functional connectivity approach, this study investigated the lateralization of the sensorimotor cortex during handwriting and drawing, two complex visuomotor tasks with varying contextual demands. We found that both left- and right-lateralized connectivity in the primary motor cortex (M1), dorsal premotor cortex (PMd), somatosensory cortex, and visual regions were evident in adults (males and females), primarily in an interhemispheric integrative fashion. Critically, these lateralization tendencies remained highly invariant across task contexts, representing a task-invariant neural architecture for encoding fundamental motor programs consistently implemented in different task contexts. Additionally, the PMd exhibited a slight variation in lateralization degree between task contexts, reflecting the ability of the high-order motor system to adapt to varying task demands. However, connectivity-based lateralization of the sensorimotor cortex was not detected in 10-year-old children (males and females), suggesting that the maturation of connectivity-based lateralization requires prolonged development. In summary, this study demonstrates both task-invariant and task-sensitive connectivity lateralization in sensorimotor cortices that support the resilience and adaptability of skilled visuomotor performance. These findings align with the hierarchical organization of the motor system and underscore the significance of the functional connectivity-based approach in studying functional lateralization.
摘要：
以前的研究表明，左半球主导着运动功能，通常通过同位激活测量观察到。使用功能连接方法，这项研究调查了手写和绘画过程中感觉运动皮层的偏侧化，两个复杂的视觉运动任务，具有不同的上下文需求。我们发现初级运动皮层(M1)的左侧和右侧连接，背侧运动前皮层（PMd），体感皮层,视觉区域在成年人(男性和女性)中很明显，主要是半球间的整合方式。严重的,这些偏侧化趋势在不同的任务环境中保持高度不变，表示任务不变的神经架构，用于编码在不同任务上下文中一致实现的基本运动程序。此外,PMd在任务上下文之间表现出轻微的偏侧化程度变化，反映了高阶电机系统适应不同任务需求的能力。然而,在10岁儿童(男性和女性)中没有检测到感觉运动皮层的基于连通性的侧向化，这表明基于连通性的侧向化的成熟需要长期发展。总之,这项研究证明了感觉运动皮层中任务不变和任务敏感连通性的偏侧化，支持熟练的视觉运动性能的弹性和适应性。这些发现与运动系统的分层组织相一致，并强调了基于功能连通性的方法在研究功能侧向化方面的重要性。重要性陈述先前的研究已经证明了运动皮层的左侧激活，适应任务需求。尽管如此，运动皮层的功能连通性偏侧化及其在任务上下文中的任务依赖性变化在很大程度上仍然未知。通过采用基于连接性的方法，这项研究揭示了在成人复杂的视觉运动过程中感觉运动皮层的左侧和右侧连接。重要的是,这些横向模式在整个任务上下文中表现出坚定不移的稳定性，在背侧运动前皮层中观察到细微程度的侧向变化。同时,中年儿童缺乏类似的连通性偏侧化，这表明连接侧化的长期发展。这些结果阐明了运动皮层的连通性偏侧化特征，为运动技能的弹性和适应性的神经基础提供新的见解。
