Natural language use in habitual propositional-type thought (support from Japanese-English and English-Japanese bilingual covert codeswitching data).
The question of whether we think in natural language or in non language-specific Ã‚?MentaleseÃ‚? has been a subject of debate for some time in the psychology/philosophy-related disciplines. The answer to this question should bring us a step nearer to understanding the language/thought relationship. In this study, a tentative model of language/thought interaction is outlined in which natural language is assigned a key role in cognition as the format of habitual propositional thought. Three research paradigms were employed to test features of this model. In a preliminary survey, Japanese-English/English-Japanese bilinguals reported being conscious of making covert use of natural language in the form of inner speech, alternately using their languages (covertly codeswitching) in doing so. Two experiments were conducted to empirically verify these self-reports and extend observation beyond the realm of subjects' inner speech. In a word association test, SsÃ‚? Japanese semantic networks were equally primed by a task where they covertly organised their thoughts in preparation for delivering a short talk in Japanese as they were after periods of overt Japanese speech. In a second task subjectsÃ‚? reaction times in processing mixed language sentences where switches were occasioned by the act of accessing concepts unique to the non-base language were compared with those from mixed sentences without such a conceptual switch. SubjectsÃ‚? longer reaction times for Ã‚?conceptual modeÃ‚? switches were seen as support for the natural language based propositional thought and dual semantic storage posited in the model. The results of both experiments argue against a view of language being merely a module used by central cognition for purposes of communication, and for the idea of natural language being an essential part of the format of habitual propositional thought. The implications of these findings for the Sapir-Whorf hypothesis and, more generally, for the future direction of psychological research are discussed.
Keywords: bilingual, covert codeswitching, cognitive role of language, covert language use, Fodor/Carruthers debate, language/thought relationship, lingpack, linguistic relativity, Sapir-Whorf hypothesis.