视觉意识相关的ERP成分及研究简评

Brief review of event-related potential correlates of visual consciousness and related studies

关于人类意识(尤其视觉意识)的研究越来越多,其中包括各种实验范式(如掩蔽、双眼竞争、注意瞬脱、变化视盲等)与研究方法(如行为实验、ERP以及fMRI).本文主要对使用ERP(事件相关电位)技术考察视觉意识的研究进行综述,并对视觉意识相关的ERP成分进行简要介绍.众多研究发现,主要有3个ERP成分与视觉意识相关,即P1,"视觉意识负波"(VAN,刺激呈现大约200ms之后出现的一个负波)和晚期正成分(LP)或者P3(刺激呈现大约300ms之后出现的正成分).在这3个成分上,意识到的刺激都比未意识到的刺激所诱发波形的波幅更大.本文简要介绍了一些相关研究,并从不同注意成分与意识的关系、C1成分与意识、高层次意识的ERP研究、影响视觉意识时间进程的因素等角度,对未来的研究方向提出了一些设想.

Studies of human consciousness （especially visual consciousness） have been increased rapidly during the last decade, including those employ a wide range of paradigms such as masking, binocular rivalry, attentional blink, and change blindness and various methods such as behavior, ERP （event-related potential） and fMRI （functional Magnatic Resonance Imaging）. The present paper reviewed the ERP studies that aimed to explore the neural correlates of visual consciousness and briefly introduced the ERP correlates of visual consciousness. Three primary ERP correlates of visual consciousness were introduced： the P1 around 100 ms after stimulus onset, a negativity around 200 ms （visual awareness negativity, VAN）, and the late positivity （LP） in the P3 time window. Researches have shown that the amplitudes of ERP evoked by conscious stimuli are significantly larger than that evoked by unconscious stimuli on these three components. Relevant researches were briefly introduced and several research directions and ideas for future studies were proposed from the point of views of the relationship between various attention components and consciousness, the relationship between C1 component and consciousness, the ERP research on high-order consciousness, and the factors affecting the time course of visual consciousness.