University of California.
University of Trento, Italy.
J Cogn Neurosci. 2019 Jun;31(6):791-807. doi: 10.1162/jocn_a_01390. Epub 2019 Mar 18.
Previous evidence from neuropsychological and neuroimaging studies suggests functional specialization for tools and related semantic knowledge in a left frontoparietal network. It is still debated whether these areas are involved in the representation of rudimentary movement-relevant knowledge regardless of semantic domains (animate vs. inanimate) or categories (tools vs. nontool objects). Here, we used fMRI to record brain activity while 13 volunteers performed two semantic judgment tasks on visually presented items from three different categories: animals, tools, and nontool objects. Participants had to judge two distinct semantic features: whether two items typically move in a similar way (e.g., a fan and a windmill move in circular motion) or whether they are usually found in the same environment (e.g., a seesaw and a swing are found in a playground). We investigated differences in overall activation (which areas are involved) as well as representational content (which information is encoded) across semantic features and categories. Results of voxel-wise mass univariate analysis showed that, regardless of semantic category, a dissociation emerges between processing information on prototypical location (involving the anterior temporal cortex and the angular gyrus) and movement (linked to left inferior parietal and frontal activation). Multivoxel pattern correlation analyses confirmed the representational segregation of networks encoding task- and category-related aspects of semantic processing. Taken together, these findings suggest that the left frontoparietal network is recruited to process movement properties of items (including both biological and nonbiological motion) regardless of their semantic category.
先前的神经心理学和神经影像学研究证据表明,在一个左额顶网络中,工具和相关语义知识具有功能专业化。这些区域是否参与了基本运动相关知识的表示,而不考虑语义领域(有生命与无生命)或类别(工具与非工具物体),这仍然存在争议。在这里,我们使用 fMRI 记录了 13 名志愿者在视觉呈现的来自三个不同类别的物品上执行两个语义判断任务时的大脑活动:动物、工具和非工具物体。参与者必须判断两个不同的语义特征:两个物品是否通常以相似的方式移动(例如,风扇和风车以圆周运动移动),或者它们是否通常出现在相同的环境中(例如,跷跷板和秋千出现在操场上)。我们研究了跨语义特征和类别在整体激活(涉及哪些区域)和表示内容(编码哪些信息)方面的差异。体素水平的多元分析结果表明,无论语义类别如何,在处理原型位置信息(涉及前颞叶皮层和角回)和运动信息(与左顶下和额叶激活有关)之间都会出现分离。多体素模式相关分析证实了编码语义处理任务和类别相关方面的网络的表示分离。总之,这些发现表明,左额顶网络被招募来处理物品的运动属性(包括生物和非生物运动),而不考虑其语义类别。