Xu Chuan, Li Hangcheng, Gao Jiaxin, Li Lingling, He Fangping, Yu Jie, Ling Yi, Gao Jian, Li Jingqi, Melloni Lucia, Luo Benyan, Ding Nai
Department of Neurology, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, China.
Department of Rehabilitation, Hangzhou Mingzhou Brain Rehabilitation Hospital, Hangzhou 311215, China.
Cereb Cortex. 2023 Mar 10;33(6):2507-2516. doi: 10.1093/cercor/bhac222.
When listening to speech, cortical activity can track mentally constructed linguistic units such as words, phrases, and sentences. Recent studies have also shown that the neural responses to mentally constructed linguistic units can predict the outcome of patients with disorders of consciousness (DoC). In healthy individuals, cortical tracking of linguistic units can be driven by both long-term linguistic knowledge and online learning of the transitional probability between syllables. Here, we investigated whether statistical learning could occur in patients in the minimally conscious state (MCS) and patients emerged from the MCS (EMCS) using electroencephalography (EEG). In Experiment 1, we presented to participants an isochronous sequence of syllables, which were composed of either 4 real disyllabic words or 4 reversed disyllabic words. An inter-trial phase coherence analysis revealed that the patient groups showed similar word tracking responses to real and reversed words. In Experiment 2, we presented trisyllabic artificial words that were defined by the transitional probability between words, and a significant word-rate EEG response was observed for MCS patients. These results suggested that statistical learning can occur with a minimal conscious level. The residual statistical learning ability in MCS patients could potentially be harnessed to induce neural plasticity.
在听言语时，皮层活动能够追踪诸如单词、短语和句子等心理构建的语言单位。最近的研究还表明，对心理构建的语言单位的神经反应可以预测意识障碍（DoC）患者的预后。在健康个体中，语言单位的皮层追踪可以由长期的语言知识和音节之间过渡概率的在线学习驱动。在这里，我们使用脑电图（EEG）研究了处于最小意识状态（MCS）的患者和从MCS中苏醒的患者（EMCS）是否能够进行统计学习。在实验1中，我们向参与者呈现了一个等时的音节序列，该序列由4个真实的双音节词或4个颠倒的双音节词组成。试验间相位相干分析表明，患者组对真实词和颠倒词表现出相似的单词追踪反应。在实验2中，我们呈现了由单词之间的过渡概率定义的三音节人造词，并且在MCS患者中观察到了显著的词率脑电图反应。这些结果表明，在最低意识水平下也能进行统计学习。MCS患者中残留的统计学习能力可能被用于诱导神经可塑性。
