字频和预存表征对相继记忆效应的影响

Effects of Character Frequency and Preexisting Representation on the Subsequent Memory Effect

采用学习-再认研究范式和事件相关电位方法，研究高频字、低频字、假字和非字的相继记忆效应(Dm效应)。18名大学生为被试，根据其测验结果将刺激分成记住和未记住两类，对相应编码过程的ERPs进行分析。结果表明：（1）真字中发现了相继记忆效应，低频字比高频字的相继记忆效应更大，随后正确再认的 ERPs 比不能正确再认的ERPs有更大的晚正成份；（2）非字中的相继记忆效应比真字中的效应更大，出现的时间也较早(140ms~200ms)，而假字中没有发现显著的相继记忆效应。这些结果表明，字频是影响相继记忆效应的重要因素，高、低频字的相继记忆效应可能存在不同的神经机制，而预存表征不是相继记忆效应出现与否的前提条件。

The late positive component (LPC) difference based on later memory performance is called the Dm effect. Many studies have shown that the LPC for items recognized in a subsequent memory test was more positive than for those that were not recognized. This effect was moderated by many factors， such as material type， encoding or orientating tasks， testing format， and study-test relationship. Most of the existing studies found that the low-frequency words showed a greater Dm effect than did the high-