知道感（FOK）和不知道感（FOnK）的实验分离

新近的脑成像研究结果提示：“知道感”（FOK）与“不知道感”（FOnK）可能是由两种不同的认知与脑机制所实现的。尽管这一设想质疑了以往的知道感研究中对此二者不加区分的处理方法，但脑成像研究在本质上是一种相关研究，因而并不能提供因果性的推论。这项行为实验将加工深度对FOK和FOnK的影响分开来加以考察，结果发现：深度加工只能使FOK的预测准确性增加，但却不但不能使FOnK的预测准确性增加，反而会使之降低。上述结果在（1）被试内设计，（2）被试间设计，（3）排除熟悉性所导致的不确定的再认等三种情况下都成立。上述结果为知道感的“双过程假设”提供了来自行为研究的证据。

Feeling-of-Knowing (FOK) and Feeling-of-not-Knowing (FOnK):An Experimental Disassociation

Recent neuroimaging studies implied that feeling-of-knowing (FOK) and feeling-of-not-knowing (FOnK) might be subserved by different cognitive and neural processes ( Chinese Science Bulletin 2002, 47:1876-9; Progress in Natural Science 2003, 13: 263-8; Acta Psychologica Sinica 2004, 36: 426-33). Although this hypothesis challenged the traditional view that regarded FOK as a continuum, the neuroimaging study cannot provide causal inference given this kind of study is correlation in nature. In this behavioural study, we examined the effects of level-of-processing (LOP) on FOK and FOnK respectively. Our results showed deep LOP promoted the prediction accuracy of FOK but not that of FOnK, in fact, deep LOP deteriorated the accuracy of FOnK. This result was obtained in both of the within-subject design and the between-subject design; it was also tenable when we excluded the recognition that was realized through familiarity heuristic.