First-Pass Selectivity for Semantic Categories in Human Anteroventral Temporal Lobe
First-Pass Selectivity for Semantic Categories in Human Anteroventral Temporal Lobe
复制标题
DOI：
10.1523/jneurosci.3122-11.2011
复制
发表时间：
2011-12-07
影响因子：
5.3
通讯作者：
Halgren, Eric
中科院分区：
文献类型：
--
作者：
Chan, Alexander M.;Baker, Janet M.;Halgren, Eric
大脑如何编码单词所代表的语义概念是认知神经科学的一个基本问题。血流动力学神经影像学研究有力地表明，动物和人造物体的图像选择性地激活后腹侧颞叶的不同区域。有时也会看到这些区域对代表动物和物体的单词的选择性反应，但它们是任务依赖性的，这表明后腹侧颞叶皮层可能编码视觉类别，而更多的前部区域编码语义类别。在这里，利用颅内宏电极和微电极阵列提供的时空分辨率，我们报告了对代表人类前腹颞区（包括颞下皮质、鼻周皮质和内嗅皮质）的动物和物体的单词的类别选择性反应。这种选择性概括了任务和感觉模式，表明它代表了抽象的词汇语义类别。在对突触活动（局部场电位、高伽玛功率、电流源和汇）和单元发射（多单元和单单元活动）敏感的测量中发现了显着的类别特异性响应。类别选择性反应可以在中皮质层的短潜伏期（早至 130 毫秒）发生，因此在通过前腹侧颞叶的第一次活动中被提取。当任务需要时，这种激活可以为后部区域提供图像表征的输入，也可以为海马结构提供输入，以进行分类编码和记忆检索，并为杏仁核提供情感关联的输入。更一般地说，这些结果支持前腹颞叶在单词语义表示中起主要作用的模型。
How the brain encodes the semantic concepts represented by words is a fundamental question in cognitive neuroscience. Hemodynamic neuroimaging studies have robustly shown that different areas of posteroventral temporal lobe are selectively activated by images of animals versus manmade objects. Selective responses in these areas to words representing animals versus objects are sometimes also seen, but they are task-dependent, suggesting that posteroventral temporal cortex may encode visual categories, while more anterior areas encode semantic categories. Here, using the spatiotemporal resolution provided by intracranial macroelectrode and microelectrode arrays, we report category-selective responses to words representing animals and objects in human anteroventral temporal areas including inferotemporal, perirhinal, and entorhinal cortices. This selectivity generalizes across tasks and sensory modalities, suggesting that it represents abstract lexicosemantic categories. Significant category-specific responses are found in measures sensitive to synaptic activity (local field potentials, high gamma power, current sources and sinks) and unit-firing (multiunit and single-unit activity). Category-selective responses can occur at short latency (as early as 130 ms) in middle cortical layers and thus are extracted in the first pass of activity through the anteroventral temporal lobe. This activation may provide input to posterior areas for iconic representations when required by the task, as well as to the hippocampal formation for categorical encoding and retrieval of memories, and to the amygdala for emotional associations. More generally, these results support models in which the anteroventral temporal lobe plays a primary role in the semantic representation of words.