Reduced intra- and inter-individual diversity of semantic representations in the brains of schizophrenia patients
Reduced intra- and inter-individual diversity of semantic representations in the brains of schizophrenia patients
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DOI：
10.1101/2020.06.03.132928
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发表时间：
2020-06
期刊：
影响因子：
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通讯作者：
S. Nishida;Yukiko Matsumoto;N. Yoshikawa;Shuraku Son;Akio Murakami;Ryusuke Hayashi;Shinji Nishimoto;Hidehiko Takahashi
中科院分区：
文献类型：
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作者：
S. Nishida;Yukiko Matsumoto;N. Yoshikawa;Shuraku Son;Akio Murakami;Ryusuke Hayashi;Shinji Nishimoto;Hidehiko Takahashi
精神分裂症患者经常表现出语义处理缺陷。有人提出，这些缺陷源于大脑中混乱的语义表征。然而，还没有研究通过直接评估大脑中的语义表征来检验语义混乱的神经相关性。我们使用功能磁共振成像信号的体素建模来评估与个体患者大脑中数千个单词相关的语义表示。然后，我们将语义表示的结构特性与健康对照组的结构特性进行了比较。与对照组相比，语义表征的变异性在个体患者内部和患者之间都较小。替代数据分析表明，观察到的代表性变异性的减少与分类信息的混乱有关。据我们所知，这些发现为精神分裂症在大脑表征水平上的语义紊乱提供了第一个证据。
Schizophrenia patients often manifest semantic processing deficits. It has been proposed that these deficits stem from disorganized semantic representations in the brain. However, no study has yet examined the neural correlates of semantic disorganization by directly evaluating semantic representations in the brain. We used voxelwise modeling on functional magnetic resonance imaging signals to evaluate the semantic representations associated with several thousand words in individual patient brains. We then compared the structural properties of semantic representations to those in healthy controls. The variability of semantic representations was smaller both within individual patients and across patients compared to controls. Surrogate data analysis suggests that the observed reduction in representational variability is associated with disorganization of categorical information. To our knowledge, these findings provide the first evidence for sematic disorganization in schizophrenia at the level of brain representations.