Abstract:

Spoken word recognition is the fundament of speech comprehension, including the activation from the acoustic information to the phonology and the semantics. Phonological information plays a critical role in spoken word recognition. Due to the sequential property of the acoustic information, people can access the phonology with the acoustic signal unfolding over time. Finally, the word semantics could be accessed. Ample evidence from behavioral, ERP and fMRI studies has found that the orthographic information is activated and influences the spoken word recognition in tasks without explicit orthographic manipulation. Seidenberg and Tanenhaus (1979) showed that rhyme judgments for spoken words were delayed when the rhyming stimuli were orthographically dissimilar, compared with when they were not (e.g., pie-rye vs. pie-pie). ERP research revealed that priming pairs sharing orthography (e.g., reef-beef) significantly reduced the N400 amplitude as compared with word pairs orthographically unrelated (e.g., sick-beef), and the topography of orthographical effect was more anterior than the phonological effect. Two different views were presented in the fMRI studies. Some researcher considered the fusiform activation as the orthographic automatic activation in spoken word processing. On the other hand, other researchers argued that during spoken language processing, the influence of orthography was resulted from orthographic restructuring of phonological representations located in the anterior perisylvian speech network. Chinese is a nontransparent language with deep orthography (i.e., there is no letter-phoneme mapping). The mapping between syllable and orthography is quite arbitrary, therefore, Chinese is replete with homophonic characters. For example, each syllable (e.g., /shi4/) is associated with a set of Chinese characters that share no orthographic components (e.g., /shi4/: 是, 市, 室, 事, 试, 示, 士, 视). This one to many mapping results in ambiguity during spoken language processing. One way to resolve the ambiguity inherent in spoken language is to write out the character. Therefore, orthographic information is important in lexical access among syllables in the auditory modality. Compared with alphabetic writing systems, in which similar pronunciations tend to have similar spellings, Chinese allows a clean dissociation between orthographic and phonological codes, allowing us to investigate orthographic effects in spoken word recognition, independent of phonology. For example, in Chinese, one syllable can be associated with two (or more) unique characters, which share no orthography (P+O-) (e.g., /shi4/ can be associated with ‘市’ or ‘事’). Similarly, one character can be associated with two pronunciations (P-O+) (e.g., ‘会’ can be pronounced as /hui4/ and /kuai4/). These homophonic and homographic dilemmas in Chinese are well resolved in disyllabic words. Within the word context (e.g. /cheng2/-/shi4/), a syllable (e.g. /shi4/) usually corresponds to a specific character (e.g. 市) therefore the correspondence between phonology, orthography and semantics is clear. When a disyllabic word is presented aurally, one may activate multiple candidate representations (or characters) during the first syllable; however, as the acoustic signal unfolds and the second syllable is perceived, contextual information is provided that allows the correct word (and character for the first syllable) to be identified. In this case, disyllabic words provide a unique way to investigate orthographic effects in Chinese spoken word recognition. Chinese can make a clear separation of the orthographic factor from the phonology factor. Therefore, it is important to understand the relation between language and reading by investigating the cognitive and neural mechanism of the orthographic processing during Chinese spoken word recognition.