The neural basis for categorization in semantic memory
The neural basis for categorization in semantic memory
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DOI：
10.1006/nimg.2002.1273
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发表时间：
2002-11-01
期刊：
影响因子：
5.7
通讯作者：
McMillan, C
中科院分区：
文献类型：
--
作者：
Grossman, M;Smith, EE;McMillan, C
我们要求年轻人根据规则或总体相似性将书面物体描述分为两类，同时我们用功能性磁共振成像（fMRI）监测局部大脑活动。我们发现，与基于相似性的分类相比，基于规则的分类显著增加了左背外侧前额叶皮层的招聘。招募右腹侧额叶皮层和丘脑是唯一与基于规则的分类以及。这些观察支持这样的主张，即执行功能，如工作记忆，抑制控制和选择性注意有助于基于规则的分类。右下顶叶激活与基于相似性的分类唯一相关。该区域可能在对于这种形式的分类很重要的整体特征配置中起重要作用。我们发现，其他大脑区域招募基于规则和基于相似性的分类：前扣带皮层可能支持执行功能的实施过程中的竞争性反应的替代方案的情况下，左下顶叶皮层可能与整合的特征知识的对象表示在特定于模态的关联皮层。我们还管理了一个退化的相似性条件下，分类的任务，一个书面的对象描述变得更加困难，通过感知退化的刺激材料。退化条件和基于规则的条件，但不是基于相似性的条件，与尾状核激活。尾状核可以支持不特定于特定分类过程的资源需求。这些发现将部分不同的大规模神经网络与语义记忆中不同形式的分类联系起来。(C)2002 Elsevier Science（美国）。
We asked young adults to categorize written object descriptions into one of two categories, based on a rule or on overall similarity, while we monitored regional brain activity with functional magnetic resonance imaging (fMRI). We found significantly greater recruitment of left dorsolateral prefrontal cortex for rule-based categorization in direct comparison with similarity-based categorization. Recruitment of right ventral frontal cortex and thalamus was uniquely associated with rule-based categorization as well. These observations lend support to the claim that executive functions such as working memory, inhibitory control, and selective attention contribute to rule-based categorization. Right inferior parietal activation was uniquely associated with similarity-based categorization. This region may play an important role in overall feature configuration that is important for this form of categorization. We found other brain regions recruited for both rule-based and similarity-based categorization: Anterior cingulate cortex may support the implementation of executive functions during situations with competing response alternatives; and left inferior parietal cortex may be related to the integration of feature knowledge about objects represented in modality-specific association cortices. We also administered a degraded-similarity condition where the task of categorizing a written object description was made more difficult by perceptually degrading the stimulus materials. The degraded condition and the rule-based condition, but not the similarity-based condition, were associated with caudate activation. The caudate may support resource demands that are not specific for a particular categorization process. These findings associate partially distinct large-scale neural networks with different forms of categorization in semantic memory. (C) 2002 Elsevier Science (USA).