关于知觉干扰效应的ERP研究

利用ERP技术，采用知觉干扰效应的经典实验范式，首次从神经生理水平上探究知觉干扰效应的内部机制。结果发现，递进条件和标准条件均诱发了P2，P3，N400和晚期正成分LPC。在P2，P3和LPC成分上，标准条件的波幅均显著大于递进条件；在N400成分上，递进条件比标准条件波幅更负，潜伏期更长。此外，对递进条件下靶字各模糊水平（Level 1～Level 5）的ERPs进行比较分析表明，N400成分的波幅在各模糊水平间的差异均不显著。基本支持失匹配理论及词汇自动加工理论。

An ERP Study on The Perceptual Interference Effect

The perceptual interference effect is the finding that prior exposures to a more degraded stimulus compromise the identification on a less degraded version of the stimulus later. Up to now, there are two influential theories which explain this effect: competition explanations (Bruner & Potter, 1964; Luo & Snodgrass, 1994; Snodgrass & Hirshman, 1991) and mismatch explanations (Wang & Reinitz, 2001). The prominent P2, P3，N400 and LPC were elicited under the experimental conditions. The amplitude of P2, P3 and LPC were significantly larger in the standard condition than in the incremental condition. The incremental condition elicited a more negative ERP deflection than did the standard condition in the 350～500 ms (N400) time window around the midline centroparietal recording sites. In addition, we found no significant differences in the 350～500 ms (N400) time window among the consecutive blurredness Levels during the incremental condition.The results indicates that perceptual interference occurs at early stages of the incremental condition and it yields an enduring inhibition, during which, the inhibition does not seem to change in magnitude. Therefore, the present results are consistent with the mismatch explanation. In addition, the study results are also consistent with the view that the N400 is sensitive to a lexical process.