Reorganization of the neurobiology of language after sentence overlearning
Reorganization of the neurobiology of language after sentence overlearning
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句子过度学习后语言神经生物学的重组
DOI：
10.1101/2020.09.11.293167
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Skipper J
中科院分区：
文献类型：
--
作者：
Skipper J
据推测，大脑中有一组静态的“语言区域”。然而，语言理解涉及的区域远远超出这些区域，当语言区域严重受损时，患者经常会产生熟悉的“公式化”表达。这表明语言的神经生物学不是固定的，而是随着经验而变化，就像单词序列学习的程度一样。我们假设感知过度学习的句子是由言语产生而不是假定的语言区域支持的。参与者接受了2次行为测试和功能性磁共振成像（fMRI）。在这15天里，他们每天重复两个句子，每个句子30次。在这两次功能性磁共振成像中，他们都是“被动地”听那些句子，新的句子，并产生句子。从行为上看，过度学习的证据包括在过度学习的句子中预测最后一个词的反应时间减少2.1秒。这对应于参与句子生成的感觉运动区域的招募，参与新句子听力的颞叶和下额叶区域的失活，以及全球网络组织的45%变化。因此，在句子过度学习之后，整个大脑发生了深刻的重组，从“语言”区域进入感觉运动区域。后者通常在失语症和阿尔茨海默病中保留，也许可以解释两者中公式化表达的残留能力。
It is assumed that there are a static set of “language regions” in the brain. Yet, language comprehension engages regions well beyond these, and patients regularly produce familiar “formulaic” expressions when language regions are severely damaged. These suggest that the neurobiology of language is not fixed but varies with experiences, like the extent of word sequence learning. We hypothesized that perceiving overlearned sentences is supported by speech production and not putative language regions. Participants underwent 2 sessions of behavioral testing and functional magnetic resonance imaging (fMRI). During the intervening 15 days, they repeated 2 sentences 30 times each, twice a day. In both fMRI sessions, they “passively” listened to those sentences, novel sentences, and produced sentences. Behaviorally, evidence for overlearning included a 2.1-s decrease in reaction times to predict the final word in overlearned sentences. This corresponded to the recruitment of sensorimotor regions involved in sentence production, inactivation of temporal and inferior frontal regions involved in novel sentence listening, and a 45% change in global network organization. Thus, there was a profound whole-brain reorganization following sentence overlearning, out of “language” and into sensorimotor regions. The latter are generally preserved in aphasia and Alzheimer’s disease, perhaps explaining residual abilities with formulaic expressions in both.