[Implicit and explicit effects of frequency on judgments of recency]

There is general agreement that repetition enhances various kinds of memory performance, but it remains unclear how repetition of identical items affects judgments of recency (JOR). The present study examined implicit repetition effects on JOR and the relationship between JOR and explicit judgments of frequency (JOF). Participants learned three lists consisting of 13 items, some of which were repeated from once to four times, and after learning each list, they judged how many times each list item was presented. Only after learning all three lists, participants could recognize the number of lists, and were asked to perform a temporal list discrimination task. The results showed that there was no significant effect of repetition on the accuracy of list discrimination but the response times for the most frequent items were significantly shorter. The results also showed a significant positive correlation between the accuracy of list discrimination and of JOF. These results suggest that higher frequency does not improve the accuracy of JOR, but intensifies the sense of easiness for the judgments, and that the ability to judge frequency contributes to JOR.