题 目：Cognitive neural mechanisms for separating reality from fantasy
田兴，北京大学物理学学士，美国马里兰大学神经与认知科学博士。现任上海纽约大学神经与认知科学助理教授。采用电生理学（脑磁图、脑电图、颅内脑电）和神经影像学（功能磁共振成像）等前沿技术手段结合行为测量和计算建模，研究言语和语言、运动感觉整合、以及记忆、想象等人类高级认知功能。主要工作包括创新性的结合想象和语言产生探索运动感觉系统交互的神经机制。已在认知神经科学领域的专业杂志上发表SCI论文三十余篇，其中包括Nature Human Behaviour, Nature Neuroscience, Psychological Science, Current Biology, PLoS Biology，Cerebral Cortex，Journal of Cognitive Neuroscience, Cognition，Cognitive Psychology等高水平期刊，担任Journal of Cognitive Neuroscience和Brain and Language等学术期刊编委，入选教育部2019年度青年长江学者奖励计划。
We can generate vivid imagination but do not confuse imagery with reality. However, schizophrenia patients commonly experience hallucinations that blur the boundary between mental operations and perception. What are the cognitive neural mechanisms that enable us to differentiate between reality and mental events? In the auditory domain, we hypothesize that neural signals transferring from the motor to sensory systems provide distinct functions to achieve the mental-reality separation – a detailed content signal (efference copy, EC) for establishing the perceptual-like neural representation from a top-down manner, as well as a general monitoring signal (corollary discharge, CD) for determining the source of such a top-down activation; Whereas in patients who suffer from auditory hallucinations, the monitoring signal (CD) is malfunctioned so that the operational top-down induced perceptual-like neural representation via EC is incorrectly attributed as externally induced. Using a novel delayed articulation paradigm with EEG recordings, we found that in normal participants, general preparation (preparing to speak without knowing what to say) induced CD and inhibited auditory neural responses (Li, Zhu & Tian, 2020). Whereas specific preparation (preparing to speak a specific syllable) induced EC and enhanced auditory neural responses to the sounds that were consistent with the specific preparation. However, in schizophrenia patients with auditory hallucinations, general preparation did not inhibit auditory neural responses, indicating the breakdown of CD; whereas the specific preparation modulated auditory responses, indicating that the EC was working. Further fMRI results suggest that the control over the motor-to-sensory transformation during mental imagery was mediated by inferior frontal and parietal cortices, and distinguish between patients and normal participants. These consistent results suggest that the interplay of distinct functional signals in the motor-to-sensory transformation balances the computational demands between executing and monitoring the top-down mental operations.