Published papers

The present study investigated how the frequently used English word wear is understood by American students and Japanese college students studying English as a second language. The results of the two experiments revealed very different patterns between the native speakers and the L2 learners. The American students knew almost all of the senses of the word wear whether used in their concrete, prototypical senses or metaphorically extended senses and grouped the different senses into tightly cohesive clusters, which in turn comprised an orderly structured category of the word as a whole. In contrast, the Japanese students’ understanding of the word was extremely impoverished, consisting only of the senses corresponding to the Japanese word “kiru”. The pattern obtained for the native speakers was consistent with a recently proposed theory treating word meaning as a structured category with single or multiple prototypes. The large difference observed between native speakers and Japanese students in understanding the meaning of a basic, frequent word such as wear points to the problem of traditional vocabulary instruction in second language class-rooms, which exclusively relies on dictionary definitions. Key words: second language, vocabulary instruction, word meaning, polysemy, structured category.

Attention during reading lessons was explored for 116 second and third graders (60 males and 56 females). Some of the concurrent and antecedent factors that influence attention were investigated. Oral reading errors undermine attention. Nominal reading group membership is more strongly related to attention than individual fluency and comprehension measures.

【シリーズ本企画】共立出版より「認知科学の探求」というシリーズを企画。学術誌「認知科学」の特集号より優れた巻を選び、改編、書き下ろし論文などを加えてシリーズ本として刊行。現在も継続中。

Children are known to use multiple sources of knowledge to constrain word meanings. Among these sources, syntactic knowledge, semantic knowledge, and familiarity have been noted as particularly important. For example, when a novel count noun is given to an unfamiliar object, English-speaking children interpret the noun as referring to an object category. When a label is given to a familiar object in the “This is X” frame, children tend to interpret it as either a proper name or a property name depending on whether the referent object is animate or inanimate (Hall, 1991, 1994; Gelman & Taylor, 1984). However, in Japanese, this clue from syntax is unavailable since the Japanese language does not have grammatical markers flagging the distinction between count nouns and mass nouns or between proper nouns and common nouns. How Japanese 2- and 4-year-olds assign meaning to novel nouns that were associated with familiar and unfamiliar animals and inanimate objects was studied in this research. The results demonstrated that in the absence of useful information from syntax, Japanese children are able to fast-map a noun to its meaning by elegantly coordinating word learning biases and other available sources of information.

The use of spacial expressions always involves some degree of ambiguity. Some of the ambiguity is quantitative. Two different perspective systems underlie the semantics of basic spatial terms such as mae, ushiro, hidari, migi (FRONT/BACK/LEFT/RIGHT). One system uses the viewer as the frame of reference (the deictic system), while the other system takes one object as the frame of reference and describes other objects with respect to this reference object (the intrinsic system). In this research, by setting up an experiment using a 3-D model space in a computer display, we empirically examined how people determined the assignment of front/back/right/left in various contexts including different types of referent objects as well as different orientations these objects were placed with respect to the perspective of the viewer. We found that at least four factors, (1)characteristics of the reference object; (2) orientation of the reference object with respect to the viewer: (3) position of the referred object with respect to the reference object; (4) method of presentation, are involved when people select one perspective system over the other, and furthermore, there is a complex interaction among these factors.

Classifiers are like nouns in that they classify entities in the world into lexical categories. However, the lexical nature of the classifier system is very different from that of nouns.The authors discuss how Japanese and Chinese children learn the meanings of classifiers, and on how classifier　acquisition is different from noun acquisition, and what the prerequisites are for spontaneous extracting the meanings of classifiers. It is shown that children are very conservative in assigning meaning to classifiers. The pace of learning largely depends on semantic complexity, across languages and within each language.

The mutual exclusivity assumption is a very useful constraint for learning basic-level category terms: children can map a novel word on to an object whose label has not yet been learned. It can also help children exclude a newly labeled object from the extension of an originally overextended old category and establish a new category. However, to learn words other than basic-level category terms, for example subordinate and superordinate category names, this assumption must be overridden. To explore under what circumstances children adhere to mutual exclusivity and under what circumstances children override this principle, two series of studies are discussed. One series demonstrated 3.5-yr-old children's failure to consider salient contextual/pragmatic information due to their adherence to mutual exclusivity. In contrast, the second series demonstrated that 36-mo-old children, by using shape similarity, could override mutual exclusivity and establish a subordinate category. By considering the discrepancy between the two studies, the metamechanism by which young children control the application of mutual exclusivity is examined.

Discusses the general agreement among researchers that word learning in young children is guided by so-called 'word-learning principles.' However, these principles may make it difficult to learn a substantial part of the lexicon unless they are appropriately controlled. To learn proper names, the taxonomic assumption and/or the shape bias must be overridden; to learn names for substances, withdrawal of the whole-object assumption and/or the shape bias is required; and to learn lexical hierarchies, the mutual exclusivity assumption must be suspended. In certain languages, syntax can provide useful information in this situation. For example, if a novel noun is given to an object for which the name is known in the syntactic frame ''This is X,'' English-speaking children may assume the noun to be a proper noun, and this will help them override the taxonomic assumption. However, this information is not available to Japanese children, since the Japanese language does not have grammatical markers to flag the distinction between count nouns and mass nouns, or the distinction between proper nouns and common nouns. The author discusses how Japanese children get around this problem.

【学会誌特集号編集】内田伸子とともにJapanese Psychological Research 41-1 特集「Lexical Development:Evalution of word-learning constraints

【解説】平凡社「世界大百貨事典」中。認知発達の理論の歴史的変遷、現在の論点などについて平易に解説