Abstract
Japanese orthography is of two types, kana and kanji. Kana is phonogram, and kanji is considered as idiogram. The present experiments were conducted with the purpose of examining differences of functions in regard to verbal materials in Japanese orthography. Verbal materials in experiments were of several single letters (kana and kanji), each corresponding to one-syllable sound; kana corresponding to the used kanji was of one syllable (phonem) without a porticular meaning, and kanji was of one syllable and one meaning.
The results of experiments were as follows. 1) In preliminary examination, the subjects were required to read a list of kana or kanji (100 letters) as fast as they could. It was found that reading kana was faster than kanji. The results suggested that as kana had just a single coding, there was linking of several letters into single unit or a string of the pronounceable letters, but as kanji had multi-coding (phonetic and semantic), there was less linking.
2) EXP. I investigated which was easier to recognize, kana or kanji. A learning list of 10 letters was made together with a test list of 5 letters of old items and 51etters of new items. In recognition task, kanji was found to be better than kana. The present studies suggested that semantic information was much more effective than phonemic information in achieving correct recognition, since more features were involved and each collection of features was highly distinctive.
3) In EXP. II, the study was to clarify the phonemic and semantic information processes in STM or LTM by free recall task. In method 1, material was of 6 lists of 10 letters (kana or kanji), and in method 2, 4 lists of 16 letters. Free recall tasks consisted of the presence or absence of delay after presentation of stimulus. In immediate recall (STM), kana was better than kanji, but in delayed recall (LTM), kanji was better than kana. When paticular phonemic code in kanji was selected by instruction, kana and kanji had the same result.
Results indicated that in STM, when the letters were encoded in terms of its phonemic features, it was better recalled than when it was encoded in terms of the semantic features; in LTM, semantic information was better recalled than phonemic information. The present study suggested the importance of S's strategy in processing of letters' information.
