| dc.description | The main intentions of the thesis were to determine the roles that word prosody may play in speech and reading and to examine the effects of sub-lexical phonology on lexical activation. The thesis also aimed to elucidate the nature of phonological processing in silent reading. Given that event-related brain potentials (ERPs) can provide reliable information concerning the timing and sequencing of linguistic processes, they were used as the primary research tool. The Phonological Mismatch Negativity (PMN) associated with phonological encoding in speech and the N400 related to semantic analysis were studied in the first two speech experiments. The N270 sensitive to form-based (orthography and phonology) processing in reading and the N400 were further examined in the third reading experiment. In the first experiment, ERPs were recorded as native English speakers listened to a series of English sentences whose terminal words were varied according to lexical stress, syllable-sized sub-lexical phonology, and semantic appropriateness. The results of this experiment showed that both the PMN and the N400 were sensitive to lexical stress and contextually primed syllables. This suggests that lexical processing primacy for non-initial-stress words is given to primarily stressed syllables instead of word onsets. In the second and third experiments, ERPs were recorded as native Chinese speakers listened to (experiment 2) or silently read (experiment 3) a series of Chinese four character proverbs whose ending characters were manipulated by lexical tone, onset, rime, and semantic variables. It was shown that both the PMN and the N400 were modulated by lexical tone and segmental manipulations. Furthermore, the N270 findings suggest the presence of orthographic-to-phonological transformation in reading. It is argued that lexical tone is involved in both Chinese speech and reading comprehension. Segments play an important role in semantic constraint not only in speech but also in reading. In all, it is concluded that word prosody is represented in the mental lexicon, which reflects aspects of a language-universal mechanism. Lexical activation progresses with directionality but not in a strictly sequential fashion. Lexical processing does not proceed in an all-or-none commitment. Instead, sub-lexical phonology exerts crucial facilitating effects on whole word/character processing. The present research provides explicit evidence that phonology plays a primary role in both speech and reading. | en_US |
