Assessing residual consciousness and cognitive abilities in unresponsive patients is a major clinical concern and a challenge for cognitive neuroscience. Although neuroimaging studies have demonstrated a potential for informing diagnosis and prognosis in unresponsive patients, these methods involve sophisticated brain imaging technologies, which limit their clinical application. In this study, we adopted a new language paradigm that elicited rhythmic brain responses tracking the single-word, phrase and sentence rhythms in speech, to examine whether bedside electroencephalography (EEG) recordings can help inform diagnosis and prognosis. EEG-derived neural signals, including both speech-tracking responses and temporal dynamics of global brain states, were associated with behavioral diagnosis of consciousness. Crucially, multiple EEG measures in the language paradigm were robust to predict future outcomes in individual patients. Thus, EEG-based language assessment provides a new and reliable approach to objectively characterize and predict states of consciousness and to longitudinally track individual patients’ language processing abilities at the bedside.

评估无反应患者的残余意识和认知能力是临床上的主要问题，也是认知神经科学的挑战。尽管神经影像学研究已显示出对无反应的患者进行诊断和预后的潜力，但这些方法涉及复杂的脑部影像技术，从而限制了其临床应用。在这项研究中，我们采用了一种新的语言范例，该范例引发了有节奏的脑反应，跟踪语音中的单个单词，短语和句子的节奏，以检查床旁脑电图（EEG）录音是否可以帮助诊断和预后。脑电图派生的神经信号，包括语音跟踪反应和全局脑状态的时间动态，都与意识的行为诊断有关。至关重要的是 语言范式中的多种EEG测度可以很好地预测个别患者的未来结局。因此，基于EEG的语言评估提供了一种新的可靠方法，可以客观地表征和预测意识状态，并在床头纵向跟踪各个患者的语言处理能力。