Rugg M D, Cox C J, Doyle M C, Wells T
Wellcome Brain Research Group, School of Psychology, University of St Andrews, Fife, U.K.
Neuropsychologia. 1995 Apr;33(4):471-84. doi: 10.1016/0028-3932(94)00132-9.
A recognition memory test was conducted in which low and high frequency words were initially presented in one of two different study tasks. A word was defined as recollected if, at test, it was both confidently judged 'old', and confidently assigned to its correct study context. Low frequency words were more accurately recognised than high frequency items, and were also more likely to be assigned to their correct study context. The results are consistent with the view that low frequency words are better recognised because they are more likely to be recollected, rather than because they engender higher levels of relative familiarity. Event-related potentials (ERPs) evoked at test by correctly classified new words were contrasted with those evoked by old, recollected words. The ERPs to low frequency words exhibited large and reliable 'old/new' effects, in that from approx. 300 msec post-stimulus, waveforms were more positive-going for old than for new items. These effects were markedly smaller, and indeed non-significant, in the ERPs evoked by high frequency items. The results show that the interaction between word frequency and old/new differences in ERPs does not arise because of a confound between frequency and the probability of recollection. Together with other findings, they suggest that recollection is better conceived of as a graded, rather than as an all-or-none phenomenon.
进行了一项识别记忆测试，其中低频和高频单词最初在两种不同的学习任务之一中呈现。如果在测试时，一个单词被自信地判断为“旧的”，并且被自信地分配到其正确的学习情境中，那么这个单词就被定义为被回忆起来了。低频单词比高频单词被更准确地识别，并且也更有可能被分配到其正确的学习情境中。这些结果与以下观点一致，即低频单词被更好地识别是因为它们更有可能被回忆起来，而不是因为它们产生了更高水平的相对熟悉度。将测试时由正确分类的新单词诱发的事件相关电位（ERP）与由旧的、被回忆起来的单词诱发的ERP进行对比。低频单词的ERP表现出大且可靠的“旧/新”效应，即从刺激后约300毫秒开始，旧项目的波形比新项目的波形更正向。在高频项目诱发的ERP中，这些效应明显较小，实际上不显著。结果表明，ERP中单词频率与旧/新差异之间的相互作用并非由于频率与回忆概率之间的混淆而产生。与其他研究结果一起，它们表明回忆更应被视为一种渐变现象，而非全或无的现象。
