Center for Mind/Brain Sciences, CIMeC, University of Trento, Palazzo Fedrigotti, Corso Bettini 31, 38068 Rovereto (TN), Italy.
J Cogn Neurosci. 2012 Oct;24(10):2096-107. doi: 10.1162/jocn_a_00257. Epub 2012 Aug 20.
Verbs and nouns differ not only on formal linguistic grounds but also in what they typically refer to: Verbs typically refer to actions, whereas nouns typically refer to objects. Prior neuroimaging studies have revealed that regions in the left lateral temporal cortex (LTC), including the left posterior middle temporal gyrus (pMTG), respond selectively to action verbs relative to object nouns. Other studies have implicated the left pMTG in action knowledge, raising the possibility that verb selectivity in LTC may primarily reflect action-specific semantic features. Here, using functional neuroimaging, we test this hypothesis. Participants performed a simple memory task on visually presented verbs and nouns that described either events (e.g., "he eats" and "the conversation") or states (e.g., "he exists" and "the value"). Verb-selective regions in the left pMTG and the left STS were defined in individual participants by an independent localizer contrast between action verbs and object nouns. Both regions showed equally strong selectivity for event and state verbs relative to semantically matched nouns. The left STS responded more to states than events, whereas there was no difference between states and events in the left pMTG. Finally, whole-brain group analysis revealed that action verbs, relative to state verbs, activated a cluster in pMTG that was located posterior to the verb-selective pMTG clusters. Together, these results indicate that verb selectivity in LTC is independent of action representations. We consider other differences between verbs and nouns that may underlie verb selectivity in LTC, including the verb property of predication.
动词和名词不仅在形式语言学上有所不同，而且在它们通常指代的内容上也有所不同：动词通常指代动作，而名词通常指代物体。先前的神经影像学研究表明，左侧颞叶外侧皮层（LTC）的区域，包括左侧后颞中回（pMTG），对动作动词的反应具有选择性，而对物体名词的反应则没有。其他研究表明，左侧 pMTG 与动作知识有关，这表明 LTC 中的动词选择性可能主要反映了动作特定的语义特征。在这里，我们使用功能神经影像学来检验这一假设。参与者在视觉呈现的动词和名词上执行简单的记忆任务，这些动词和名词描述的是事件（例如“他吃”和“对话”）或状态（例如“他存在”和“价值”）。在个体参与者中，通过动作动词和物体名词之间的独立局部对比度来定义左侧 pMTG 和左侧 STS 中的动词选择性区域。这两个区域对事件动词和状态动词的选择性都与语义匹配的名词相同。左侧 STS 对状态的反应比对事件的反应更强烈，而左侧 pMTG 中状态和事件之间没有区别。最后，全脑组分析显示，与状态动词相比，动作动词在 pMTG 中激活了一个位于动词选择性 pMTG 簇后部的簇。总的来说，这些结果表明 LTC 中的动词选择性独立于动作表示。我们考虑了动词和名词之间的其他差异，这些差异可能是 LTC 中动词选择性的基础，包括动词的断言特性。
