Kraut Michael A, Kremen Sarah, Segal Jessica B, Calhoun Vincent, Moo Lauren R, Hart John
Division of Neuroradiology, John Hopkins Hospital, Johns Hopkins University, Baltimore, MD 21287, USA.
J Cogn Neurosci. 2002 Jan 1;14(1):24-36. doi: 10.1162/089892902317205294.
The human brain is thought to elicit an object representation via co-activation of neural regions that encode various object features. The cortical regions and mechanisms involved in this process have never been elucidated for the semantic system. We used functional magnetic resonance imaging (fMRI) to evaluate regions activated during a task designed to elicit object activation within the semantic system (e.g., presenting the words "desert" and "humps" with the task to determine if they combine to form an object, in this case a "camel"). There were signal changes in the thalamus for word pairs that activated an object, but not for pairs that (a) failed to activate an object, (b) were simply semantically associated, or (c) were members of the same category. These results suggest that the thalamus has a critical role in coordinating the cortical activity required for activating an object concept in the semantic system.
人们认为，人类大脑通过共同激活编码各种物体特征的神经区域来引发物体表征。对于语义系统而言，参与这一过程的皮质区域和机制从未得到阐明。我们使用功能磁共振成像（fMRI）来评估在一项旨在引发语义系统内物体激活的任务（例如，呈现单词“沙漠”和“驼峰”，任务是确定它们是否组合形成一个物体，在这种情况下是“骆驼”）中激活的区域。对于激活物体的单词对，丘脑存在信号变化，但对于以下几种单词对则没有：（a）未能激活物体的；（b）只是语义相关的；或（c）属于同一类别的。这些结果表明，丘脑在协调语义系统中激活物体概念所需的皮质活动方面起着关键作用。
