Recognition memory studies have shown that increased perceptual fluency results in more “old” responses and, presumably, increases familiarity. However, the exact neural mechanisms of these effects remain unresolved. We conducted two ERP experiments in which participants encoded words and performed a recognition test where fluency was manipulated by changing clarity of test words (half of them were clear or blurry). In the more demanding Experiment 1, we found a reversed effect of fluency on recognition (more hits for blurry words), which was accompanied by larger N400 and LPC old/new effects for blurry words. For high confidence responses, the topography of N400 shifted towards frontal electrodes (the FN400 for blurry words). In the less demanding Experiment 2, no behavioral differences between clear and blurry words were observed. However, there was a discrepancy in the ERP results, with the frontal FN400 for blurry words and the parietal N400 for clear words, suggesting that distinct neural pathways can support familiarity-based recognition for clear and blurry items. In both experiments, early perceptual fluency ERP effects were also observed. The results indicate that both semantic processing and familiarity can be enhanced by perceptual fluency and contribute to recognition judgments, depending on the interpretations of fluency.

认知记忆研究表明，感知流利性的提高会导致“老”的响应增加，并且可能会增加熟悉度。但是，这些作用的确切神经机制仍未解决。我们进行了两个ERP实验，其中参与者对单词进行了编码，并进行了识别测试，通过改变测试单词的清晰度（其中一半是清晰或模糊的）来控制流利程度。在要求更高的实验1中，我们发现了流利度对识别的反向作用（模糊词的点击率更高），同时伴随着较大的N400和LPC对模糊词的旧/新效果。对于高置信度响应，N400的拓扑结构朝着正面电极移动（FN400表示模糊的单词）。在要求较低的实验2中，没有观察到清晰单词和模糊单词之间的行为差​​异。然而，ERP结果存在差异，正面单词FN400代表模糊单词，顶位N400代表清晰单词，表明不同的神经通路可以支持基于熟悉度的清晰和模糊条目识别。在两个实验中，还观察到了早期的感知流利性ERP效果。结果表明，取决于流畅度的解释，感知流畅度可以增强语义处理和熟悉度，并有助于识别判断。