Division of Basic Biomedical Sciences, Basic Biomedical Sciences & Center for Brain and Behavior Research, University of South Dakota Sanford School of Medicine, 414 E. Clark St., Vermillion, SD, 57069, USA.
FAA Civil Aerospace Med. Inst., Oklahoma City, OK, USA.
Exp Brain Res. 2023 Jul;241(7):1959-1971. doi: 10.1007/s00221-023-06646-1. Epub 2023 Jun 26.
The advanced use of complex tools is considered a primary characteristic of human evolution and technological advancement. However, questions remain regarding whether humans possess unique underlying brain networks that support advanced tool-using abilities. Specifically, previous studies have demonstrated the presence of a structurally and functionally unique region in the left anterior supramarginal gyrus (aSMG), that is consistently active during tool use action observation. This region has been proposed as a primary hub for integrating semantic and technical information to form action plans with tools. However, it is still largely unknown how tool use motor learning affects left aSMG activation or connectivity with other brain regions. To address this, participants with little experience using chopsticks observed an experimenter using chopsticks to perform a novel task while undergoing two functional magnetic resonance imaging (fMRI) scans. Between the scans, participants underwent four weeks of behavioral training where they learned to use chopsticks and achieve proficiency in the observed task. Results demonstrated a significant change in effective connectivity between the left aSMG and the left anterior intraparietal sulcus (aIPS), a region involved in object affordances and planning grasping actions. These findings suggest that during unfamiliar tool use, the left aSMG integrates semantic and technical information to communicate with regions involved with grasp selection, such as the aIPS. This communication then allows appropriate grasps to be planned based on the physical properties of the objects involved and their potential interactions.
复杂工具的高级使用被认为是人类进化和技术进步的主要特征。然而，关于人类是否具有支持高级工具使用能力的独特潜在大脑网络，仍存在疑问。具体来说，先前的研究表明，在左前上缘回（aSMG）存在一个结构和功能独特的区域，在工具使用动作观察期间始终活跃。该区域被提议作为整合语义和技术信息以形成使用工具的行动计划的主要枢纽。然而，工具使用运动学习如何影响左 aSMG 的激活或与其他大脑区域的连通性，在很大程度上仍然未知。为了解决这个问题，经验很少使用筷子的参与者观察实验者使用筷子执行一项新任务，同时进行两次功能磁共振成像（fMRI）扫描。在扫描之间，参与者接受了四周的行为训练，学习使用筷子并熟练掌握观察到的任务。结果表明，左 aSMG 与左前内顶叶回（aIPS）之间的有效连通性发生了显著变化，aIPS 参与物体的可及性和规划抓握动作。这些发现表明，在不熟悉的工具使用过程中，左 aSMG 整合语义和技术信息，与涉及抓握选择的区域（如 aIPS）进行交流。然后，这种通信允许根据涉及的物体的物理特性及其潜在的相互作用来规划适当的抓握。
