This study attempted to provide evidence that the visual information of Japanese kanji words has a large effect on the memory spans of native Japanese speakers, while their phonological information has a small effect. Experiment 1 examined the word-length effects of kanji words, controlling orthographic length and manipulating phonological length. The results did not show a linear function of memory span and phonological length, and revealed that fast readers were not necessarily good memorizers. Experiment 2 examined the word-length effects, controlling phonological length and manipulating orthographic length. The results revealed a clear linear function of memory span and orthographic length. Experiment 3 compared the orthographic neighborhood size effects on memory span between kanji words with standard and with special readings. The results showed that the orthographic neighborhood size effects did not differ between the two kinds of kanji words. Together, these results indicate that the visual information of kanji words has a large effect on the memory spans of native Japanese speakers, while their phonological information has only a small effect.

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Previous research has reported a positivity effect for explicit memory. However, age influences on the effects of emotional valence for implicit memory have not been investigated to date. The present study examines how emotional valence influences age differences for both explicit and implicit memory. In Experiment 1, 48 younger adults and 48 older adults encoded neutral words that were presented before either positive, negative, or neutral pictures. After encoding, the participants completed a free recall task. In Experiment 2, 27 younger adults and 30 older adults completed a word completion task after encoding using the same procedure as Experiment 1. Explicit memory in the negative condition was highest among the younger adults, and a positivity effect was observed among the older adults. Implicit memory for both the positive and negative conditions was higher than for the neutral condition for both age groups. These results suggest that the positivity effect occurs within intentional processes, which is supportive of a socio-emotional selectivity theory.

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Attraction and compromise effects that have been observed within multi-attribute decision making would seem to violate the principles of rational choice. To investigate the underlying mechanisms of these two context effects, we examine information search and acquisition patterns while recording participants' eye movements. We randomly assigned 20 undergraduates to the two context effect conditions. Participants were requested to solve 12 hypothetical purchase problems involving three alternatives described along two attribute dimensions. We observed significant context effects on choice proportions in both conditions. Eye-fixation times for selected alternatives were significantly longer and frequencies of within-saccades for selected alternatives were significantly higher in both conditions. Frequencies of between-saccades for two alternatives were also significantly higher in both conditions when the selected alternative was included. Furthermore, a time-series analysis of between-saccades for the two alternatives revealed dynamic temporal aspects, where between-saccades that included the selected alternative increased while between-saccades that did not include the selected alternative decreased. These results suggest that eye-tracking analysis is vital for investigating the mechanisms that underlie context effects during decision making.

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The effects of presentation time on the release from retrieval–induced forgetting are examined in younger (Experiment 1) and older adults (Experiment 2) using a typical retrieval practice paradigm. During the study phase, presentation time was manipulated and during the final test phase, a recognition test was conducted. In terms of recognition response times, a retrieval-induced forgetting effect was observed in both younger and older adults indicating that inhibition occurred for both age groups. In terms of recognition accuracy, younger adults did not exhibit retrieval-induced forgetting when the presentation time was long, indicating a reduction of inhibitory effect. In contrast, older adults exhibited retrieval-induced forgetting regardless of the presentation time, indicating a standard inhibitory effect. These results suggest that for younger adults, the presentation time was determining factor for the release from retrieval-induced forgetting, with release more likely at longer presentation times. On the other hand, in the older adults, release from retrieval-induced forgetting is more difficult to realize and so presentation times were not influenced by any release.

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Using the lexical decision task, we compare task performance for three- versus four-character katakana words and two- versus three-character kanji words. While no length effect was observed for katakana words, a significant effect was observed for kanji words, such that lexical decision latencies were longer for three-character kanji words than for two-character kanji words. This effect was observed even when orthographic neighborhood sizes were matched across the two kanji-word groups. Because the kanji words are compound words, but the katakana words are mono-morphemic words, the observation of a length effect only for kanji words may indicate that the effect is due to the difference in the number of morphemes. Assuming morphological decomposition for kanji compound words, the constituent morphemes would have to be recombined to access to whole-word representations. Thus, the length effect could arise within the recombination process because three-character kanji compounds have more complicated morphological structures than two-character kanji compounds. As such, the present results suggest that the nature of reading process is highly dependent on the morphological structure that a word possesses.

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In order to examine whether naming performance for Japanese kanji words is determined by the degree of orthographic–phonological consistency at the kanji character level or by the type of readings for the constituent kanji characters (on readings versus kun readings), naming performance was compared for on-reading and kun-reading two-character kanji words with matched orthographic–phonological consistencies in Experiment 1. In Experiment 2, naming performance was compared for kun-reading single-character kanji words with higher and lower on-reading ratios. In Experiment 1, naming performance was comparable for the on-reading and kun-reading words. In Experiment 2, naming responses were faster for kanji characters with lower on-reading ratios than for those with higher on-reading ratios. These results clearly suggested that naming performance for kanji words is modulated by the degree of orthographic–phonological consistency but not by the type of readings possessed by the constituent kanji characters.

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This study examined development of construction of drawing in young children from the perspectives of spatial cognition and switching of reaction. Twenty 4-year-olds, 22 5-year-olds and 21 6-year-olds were participated in the next three tasks: drawing task, spatial cognitive task, and switching task. The main findings were as follows: (1) In the drawing task, noncanonical drawing increased from 5-year-olds to 6-year-olds. (2) For both spatial cognitive task and switching task, the scores increased with age. (3) The scores of spatial cognition and switching in noncanonical drawing group were higher than that of canonical drawing group. These results suggested that both of spatial cognition and switching were related to the development of construction of drawing in young children.

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