识别电位（recognition potential，RP）是由可识别的视觉刺激所诱发的、在刺激出现后200－300 ms达到峰值的脑电反应。先前研究表明，RP可能是人类视觉识别的脑电指标。但是，目前尚不清楚RP所反映的认知机制及其皮层发生源。RP可能受到视觉识别中的两个关键认知活动的影响：视觉特征的提取和整合以及刺激与记忆表征的匹配。先前的研究无法说明二者对RP的影响。因此，项目的第一个目标是考查两个认知活动对RP的贡献大小。项目拟结合心理物理法和单试次EEG分析技术来量化这两个认知活动，再将二者的行为量化观测值与个体的ERP观测值进行回归分析。项目的第二个目标是拟采用同步EEG-fMRI技术对RP进行神经源定位。项目首次结合这些方法来探讨RP的认知机制和其神经发生源。项目的研究结果将为RP研究提供重要的实证依据和理论参考，对深入理解视觉系统的工作原理有重要的意义。

The recognition potential (RP), an electrical brain response peaking around 200–300 milliseconds, is typically observed when participants view visually recognizable stimuli. Previous studies suggest that RP is an important biomarker of human visual recognition. However, its cognitive mechanism and neural source location are still unclear. RP might be affected by two cognitive activities critical for visual recognition: extraction and grouping of visual features; and matching a stimulus with stored memory representations. However, previous studies have left unclear the relative contribution of these two activities to generation of the RP. In order to determine the exact contribution of feature grouping and stimulus matching to the RP, the first part of the current project will combine psychophysical methods with single trial EEG analysis to parametrically measure these two activities. They will be quantified as efficiency of feature grouping and memory representation strength. These two quantified measurements will then be modelled against EEG amplitudes in order to separate out their individual contributions to the RP. The second part of the project will then use simultaneous EEG-fMRI techniques to locate the neural generators of the RP. This localisation information will compliment the findings of part one of the project by matching regional function to cognitive processes. The findings of this project will for the first time employ these methods to determine the cognitive processes involved in the generation of the RP and identify the locations in the brain from which it arises. This knowledge will provide essential background for RP research and will represent a significant contribution to our understanding of vision in general.