The Japanese Mental Lexicon: The Lexical Retrieval and Representation of Two-Kanji Compound Words from a Morphological Perspective Terry Joyce 975058 Thesis Submitted to the Institute of Psychology, University of Tsukuba in Part Fulfillment of Requirements for the Degree of Doctor of Philosophy (Psychology) 2001 Academic Year Abstract At its most general level, this research takes a psycholinguistic approach in seeking an acceptable answer to the question how do kanji function as a writing system? In pursuing this answer, the thesis takes the two-kanji compound word as its principle frame of reference. The emphasis on the two-kanji compound word, rather than on the single kanji character, follows from a belief that to understand how a writing system functions it is essential to identify the principles that govern the combination of graphic units. In searching for an answer to the research question, this thesis explores and traces the connections between four broad areas; namely, the classification of the Japanese writing system, Japanese word formation, visual word recognition, and, in particular, the Japanese mental lexicon. Given that the nature of a writing system will be reflected in the structure of the literate mental lexicon, the transition from writing system to mental lexicon is simply a shift in perspective—from external form to internal representation. The answer that emerges from the exploration of these areas is that kanji function as a morphographic writing system, and, moreover, this is reflected in the Japanese mental lexicon. Part 1 of this thesis is linguistic in nature, focusing primarily on the external form. Based on discussion concerning the appropriate classification of the Japanese writing system, and, especially of kanji, within a linguistic taxonomy of writing systems, it is argued that kanji may be most accurately characterized as a morphographic writing system. Evidence for this is provided by looking ii Abstract at the word formation processes that underlie two-kanji compound words, which are primarily morphological. Compounding is the combining of abstract linguistic elements—morphemes—to form larger word units, with the representation of these larger word units being a product of combining the constituent representations. The discussion of two-kanji compound word morphology also provides background for the experiments presented in this thesis. Part 2 of the thesis is psycholinguistic in nature, focusing primarily on the internal representation. After arguing in Part 1 that kanji function as a morphographic writing system, Part 2 investigates the implications of this for the organization of the Japanese mental lexicon. Specifically, a lemma unit model version (Joyce, 1999, in press) of the multilevel interactive-activation framework is proposed as a model for the Japanese mental lexicon. The major feature of the lemma unit model is the incorporation of lemma units that mediate the links between access representations and semantic units. This model is examined through a series of constituent-morpheme priming experiments, which investigated the lexical retrieval and representation of two-kanji compound words within the Japanese mental lexicon from a morphological perspective by controlling for the word-formation principle of compound word stimuli as an experimental condition. As background to the conducted experiments, important tasks and effects are discussed in a brief review of visual word recognition research, which focuses on the two central issues for the mental lexicon—lexical retrieval and lexical representation. A short review of models of lexical representation, which all allow for some form of morphological involvement in the lexical retrieval of iii Abstract polymorphemic words, also highlights the language-universal importance of morphology for the organization of the mental lexicon. As any model of the Japanese mental lexicon must in some way capture the morphological relations that exist between polymorphemic words, two proposals for models of the Japanese mental lexicon—Hirose’s (1982, 1994, 1996) hypotheses and Joyce’s (1999, in press) suggestion for a Japanese lemma unit model—are investigated in terms of their ability to cope with the diversity in the morphology of two-kanji compound words. Because these proposals make different predictions concerning constituent-morpheme priming, the patterns of facilitation are examined in two experiments varying stimulus onset synchronicity (SOA) with five word-formation principles as experimental conditions. The results from these experiments, of similar levels of priming for both constituents in all but one word-formation condition, are more consistent with the predictions from the Japanese lemma-unit model. The lemma unit model is investigated further through a series of seven experiments that seek to examine various aspects of this model of the Japanese mental lexicon. While these experiments retain a focus on the lexical retrieval and representation of two-kanji compound words from a morphological perspective, they also investigate the extent to which the results in the first two experiments might be task specific, the possibility that the lemma unit model offers to integrate both kana and kanji processing within a single model, and the potential to model the dual reading system of on-readings and kun-readings. In addition, by employing recently compiled constituent-morpheme frequency data (Joyce & Ohta, in press), the issue of positional sensitivity is examined for verbal constituent morphemes of two-kanji compounds words. Although the iv Abstract results from this series of experiments raise further questions, they are generally consistent with the lemma unit model, which is undoubtedly an extremely appealing way of thinking about the relations that exist between semantic representations, and access representations for orthography and phonology, as well as accounting for the morphological information that underlies two-kanji compound words in the Japanese mental lexicon. This investigation of the lexical retrieval and representation of two-kanji compound words within the Japanese mental lexicon from a morphological perspective has serious implications for our understanding of kanji, as well as for our perception of writing systems and of language itself. v Acknowledgements I would like to thank many of the wonderful people I have been privileged to meet and know in the course of my studies. Without their kind help, in various ways, it simply would not have been possible for me to undertake this research and to write this thesis. For failing to make better use of all this kind help, much to the detriment of this thesis, I can only offer my sincere apologizes. I shall be eternally indebted to Professor Ohta Nobuo, who has supervised and supported my research over the past five years with so much patience, kindness, and consideration. I shall also always remember the advice, support, kindness, and friendship of all associated with Professor Ohta’s laboratory during that time. The visiting foreign lecturers: Firstly, Dr. Bradford Challis, for advice on the preparation of my first experiments, and, later, Dr. Ulrich Olofsson, for help with analyzing those initial results. The post-doctoral research fellow: Dr. Eleanor Olds Batchelder for beneficial ‘prodding’ and discussion as I struggled to write my master’s thesis. The senpai: Dr. Terasawa Takafumi, Dr. Kawano Rie, and Yoshida Tetsuya for the benefit of their experience and kindness. The dōkyūsei: Gotoh Fumiko, Hayashi Mitsuko, and Hoshino Satoshi for support throughout. Beyond Professor Ohta’s laboratory, I have also benefited greatly from the advice, help, and kindness from many at the Institute of Psychology during this time, and I would like to thank everyone for that. In particular, I would like to mention the following people: Professor Kaiho Hiroyuki for his kind concern vi Acknowledgements and encouragement. Professor Kikuchi Tadashi for the loan of equipment used in conducted naming experiments. Dr. Aoyama Masahiko, for advice on the preparation of a number of experiments, as well as helpful comments on a draft manuscript. Dr. Nanbu Misako, for her generous time and help with so many of the conducted experiments. Dr. Yugawa Shintaro, for various help. Dr. Kobayashi Takefumi, for help with a translation. Shimada Hideaki for helpful discussion of ratios. Nakajima Masato for advice on waveform data. My special thanks also to Yagi Yoshihiko for his technical knowledge in making the naming experiments possible. And, to Simon Downes for his friendship and for sharing the experience of being a foreign graduate student in the department. Beyond the Institute of Psychology, I have received help from many people in other departments at the University of Tsukuba. I would like to express my thanks to Dr. Stefan Kaiser for his advice and help as supervisor during my first two years in Tsukuba and since then, and to all the Japanese language teachers at the Foreign Student Center. For allowing me to recruit participants for my experiments at their classes, I am grateful to the following lecturers: in the Area Studies program, Dr. Philip Hansen, and at the Foreign Language Center, Andrew Barfield, Dr. Joe Johnson, Alan Milne, Sakuma Yasuyuki, and Garth Warries. In addition to their help with recruiting, I also wish to thank Dr. Yvonne Stapp for all her kindness and words of encouragement, and at the Institute of Literature and Linguistics, Dr. John Shillaw for much help and advice, especially