Northwestern University, Department of Psychology, 2029 Sheridan Road, Evanston, IL 60208, USA.
Neuropsychologia. 2012 Nov;50(13):3041-52. doi: 10.1016/j.neuropsychologia.2012.07.036. Epub 2012 Aug 6.
The neural mechanisms that underlie familiarity memory have been extensively investigated, but a consensus understanding remains elusive. Behavioral evidence suggests that familiarity sometimes shares sources with instances of implicit memory known as priming, in that the same increases in processing fluency that give rise to priming can engender familiarity. One underappreciated implication of this account is that patterns of neural activity that appear to index familiarity in a generic sense may instead reflect fluency-related precursors of recognition. In a novel illustration of this principle, we examined brain potentials during recognition tests for visual words. In two experiments, fluency was selectively enhanced for half of the test cues via masked repetition priming. Replicating previous findings, the proportion of words endorsed as "old" was greater for words immediately preceded by a matching masked word versus an unrelated one. In addition, N400 potentials were more positive for test cues preceded by matching versus unrelated masked words. Similar N400 differences were observed when false alarms were compared to correct rejections for the subset of unstudied words that were preceded by matching masked words. These N400 effects were topographically dissociable from other potentials that correlated with familiarity for studied words. We conclude that experiences of familiarity can have different neural correlates that signal the operation of distinct neurocognitive precursors of recognition judgments. Conceptualizations of the neural basis of recognition memory must account for a plurality of mechanisms that produce familiarity memory.
熟悉记忆的神经机制已经得到了广泛的研究，但共识仍然难以达成。行为证据表明，熟悉感有时与内隐记忆的实例（即启动）共享来源，因为导致启动的处理流畅度的增加同样可以产生熟悉感。这一解释的一个被低估的含义是，在广义上似乎可以指示熟悉感的神经活动模式，可能反而反映了与识别相关的流畅度前体。在这一原则的一个新例证中，我们在视觉单词的识别测试中检查了脑电波。在两项实验中，通过掩蔽重复启动，有一半的测试线索的流畅度被选择性地增强。与之前的发现一致，与不相关的掩蔽词相比，与匹配的掩蔽词直接相邻的单词被认为是“旧”词的比例更大。此外，对于由匹配的掩蔽词而不是不相关的掩蔽词所引导的测试线索，N400 电位更为正。当将假警报与正确拒绝进行比较时，对于由匹配的掩蔽词所引导的未学习单词子集，也观察到了相似的 N400 差异。这些 N400 效应与其他与学习单词的熟悉度相关的电位在拓扑上是可分离的。我们的结论是，熟悉感的体验可能具有不同的神经相关性，这些相关性可以指示识别判断的不同神经认知前体的运作。对识别记忆的神经基础的概念化必须考虑到产生熟悉记忆的多种机制。
