An architecture for encoding sentence meaning in left mid-superior temporal cortex
An architecture for encoding sentence meaning in left mid-superior temporal cortex
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DOI：
10.1073/pnas.1421236112
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发表时间：
2015-09-15
影响因子：
11.1
通讯作者：
Greene, Joshua D.
中科院分区：
文献类型：
--
作者：
Frankland, Steven M.;Greene, Joshua D.
人类的大脑灵活地联合收割机组合单词的含义来组成结构化的思想。例如，通过组合“bite”、“dog”和“man”的含义，我们可以想到一只狗咬一个人，或者一个人咬一只狗。在这里，在两个功能磁共振成像（fMRI）实验中使用多体元模式分析（MVPA），我们确定了一个区域的左中上部颞叶皮层（lmSTC），灵活地编码“谁做了什么给谁”在视觉上呈现的句子。我们发现lmSTC表示抽象语义变量的当前值（“Who did it？“和“对谁做的？“）。实验1首先确定了lmSTC的一个广泛区域，其活动模式（i）促进结构依赖性句子意义的解码（“谁对谁做了什么？）和（ii）预测依赖于该信息的情感相关杏仁核反应（例如，“婴儿踢了祖父”与“祖父踢了婴儿”）。实验2，然后确定不同的，但相邻的，lmSTC的活动模式携带信息的身份，当前的“代理”（“谁做的？“）和当前的“病人”（“这是对谁做的？").这些相邻的亚区分别位于沿着上级颞沟的上岸和上级颞回的外侧岸。在高层次上，这些区域可以像地形定义的数据寄存器一样工作，对抽象语义变量的波动值进行编码。这种功能架构在关键方面类似于经典计算机，可能在使人类能够灵活地产生复杂思想方面发挥关键作用。
Human brains flexibly combine the meanings of words to compose structured thoughts. For example, by combining the meanings of "bite," "dog," and "man," we can think about a dog biting a man, or a man biting a dog. Here, in two functional magnetic resonance imaging (fMRI) experiments using multivoxel pattern analysis (MVPA), we identify a region of left mid-superior temporal cortex (lmSTC) that flexibly encodes "who did what to whom" in visually presented sentences. We find that lmSTC represents the current values of abstract semantic variables ("Who did it?" and "To whom was it done?") in distinct subregions. Experiment 1 first identifies a broad region of lmSTC whose activity patterns (i) facilitate decoding of structure-dependent sentence meaning ("Who did what to whom?") and (ii) predict affect-related amygdala responses that depend on this information (e.g., "the baby kicked the grandfather" vs. "the grandfather kicked the baby"). Experiment 2 then identifies distinct, but neighboring, subregions of lmSTC whose activity patterns carry information about the identity of the current "agent" ("Who did it?") and the current "patient" ("To whom was it done?"). These neighboring subregions lie along the upper bank of the superior temporal sulcus and the lateral bank of the superior temporal gyrus, respectively. At a high level, these regions may function like topographically defined data registers, encoding the fluctuating values of abstract semantic variables. This functional architecture, which in key respects resembles that of a classical computer, may play a critical role in enabling humans to flexibly generate complex thoughts.