MRC Cognition and Brain Sciences Unit, 15 Chaucer Rd., Cambridge, UK.
Nat Commun. 2012 Feb 28;3:711. doi: 10.1038/ncomms1715.
Rapid information processing in the human brain is vital to survival in a highly dynamic environment. The key tool humans use to exchange information is spoken language, but the exact speed of the neuronal mechanisms underpinning speech comprehension is still unknown. Here we investigate the time course of neuro-lexical processing by analyzing neuromagnetic brain activity elicited in response to psycholinguistically and acoustically matched groups of words and pseudowords. We show an ultra-early dissociation in cortical activation elicited by these stimulus types, emerging ∼50 ms after acoustic information required for word identification first becomes available. This dissociation is the earliest brain signature of lexical processing of words so far reported, and may help explain the evolutionary advantage of human spoken language.
人类大脑的快速信息处理对于在高度动态的环境中生存至关重要。人类用来交换信息的关键工具是口语，但支持言语理解的神经元机制的确切速度仍不清楚。在这里，我们通过分析对心理语言学和声学匹配的词和假词组产生的神经磁脑活动来研究神经词汇处理的时间过程。我们表明，这些刺激类型引起的皮层激活存在超早期分离，出现在用于单词识别的声学信息首次可用之后约 50 毫秒。这种分离是迄今为止报道的词汇处理单词的最早大脑特征，可能有助于解释人类口语的进化优势。
