Three experiments investigated the effects of semantic and sensory information on the relationships between recognition accuracy and confidence ratings by comparing the calibration curves consisting of subjective rates of old and new responses with those consisting of nominal rates of old and new responses. In these experiments, college students (n=273) intentionally studied words, then received a recognition test and rated confidence in their recognition responses. To investigate the effects of semantic information on the calibration curves, the similarities between old and new items were varied. Experiments 1 (visual) and 2 (auditory) used the same presentation modality of study and test words. Experiment 3 used an auditory presentation of study words and visual presentation of test words. Analyses of the nominal responses showed poor or negative calibration curves by the semantic confusing as preceding results. In contrast, the analyses of the subjective responses revealed good calibration curves, if only either of semantic or sensory information could be available for recognition judgments. The present results indicate the importance of subjective analysis of recognition responses.

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The purpose of this study is to elucidate the developmental changes in self-assessments of everyday memory during adulthood using the Everyday Memory Questionnaire (EMQ). A total of 299 adults (99 younger (Y: 19–25 years), 97 middle-aged (M: 38–55 years), and 103 older (O: 63–75 years)) participated in the study. The participants were asked to rate 28 items, each describing an everyday activity that involves forgetting or memory failures, on 9-point scales from 1 (not at all in the last six month) to 9 (more than once a day). The results indicate developmental differences among the younger, middle-aged, and older participants in terms of mean ratings for five subgroups of the items based on the factorial structure of the EMQ derived from previous studies (e.g., Shimizu, Takahashi, & Saito, 2006, 2007), such that five patterns could be discerned; (a) Y=M=O, (b) Y>M>O, (c) Y=M>O, (d) Y>M=O, and (e) Y>O. These results suggest that a developmental shift gradually occurs in self-assessments of everyday memory from pessimistic to optimistic perspectives concerning own memory abilities throughout adulthood.

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Studies of sequence learning have documented memory consolidation, in which post-learning sleep facilitates the retrieval of items from a succeeding chunk while retrieving items from a prior chunk. However, it remains unclear what changes in the representation of a learned sequence are induced by sleep. We investigate whether post-learning sleep strengthens the connections between chunks or between individual items within a sequence. After learning a sequence as two separate chunks, participants retrieved the middle part of the sequence, consisting of the second half of the first chunk and the first half of the second chunk, either as an isolated sequence or as part of the complete learned sequence. The results show that sleep improved retrieval of the middle part only in the complete sequence condition, suggesting that sleep strengthens the connections between chunks, rather than between items, and that the chunk structure is retained after memory consolidation.

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