Hsuan-Chih Chen

The development of phonological awareness: effects of spoken language experience and orthography

Phonological awareness, the ability to analyze spoken language into small sound units, has been shown to be affected by the individuals early orthographic experience (alphabetic vs. non-alphabetic). Past studies, however, have not differentiated the effect of script alphabeticity from that of spoken language experience, which covaries strongly with the phonological properties of the language. The present study compares younger, pre-reading to older, literate children from different linguistic backgrounds on their phonological awareness. Hong Kong and Guangzhou subjects both spoke Cantonese. The latter subjects had early experience with Pinyin (alphabetic) in addition to their logographic Chinese reading; the former read only logographic Chinese. New Zealand subjects spoke English and read the Roman alphabet. Results showed that: (1) the Hong Kong and Guangzhou pre-readers performed very similarly at all levels of phonological awareness; (2) the New Zealand pre-readers outperformed their Hong Kong and Guangzhou counterparts on onset, rime, and coda analyses; (3) the Guangzhou reading children outperformed their Hong Kong counterparts on onset and coda analyses. Whereas finding (3) reflects an effect of alphabeticity in the first learned script, finding (2) in combination with finding (1) indicates an effect of early spoken language experience independent of orthography. The fact that orthographic and spoken language experience both impact on the development of phonological skills implies a mediating function of phonological awareness in integrating sound information derived from reading and perceiving speech.

Brain Responses to Segmentally and Tonally Induced Semantic Violations in Cantonese

The present event-related potential (ERP) study examined the role of tone and segmental information in Cantonese word processing. To this end, participants listened to sentences that were either semantically correct or contained a semantically incorrect word. Semantically incorrect words differed from the most expected sentence completion at the tone level, at the segmental level, or at both levels. All semantically incorrect words elicited an increased frontal negativity that was maximal 300 msec following word onset and an increased centroparietal positivity that was maximal 650 msec following word onset. There were differences between completely incongruous words and the other two violation conditions with respect to the latency and amplitude of the ERP effects. These differences may be due to differences in the onset of acoustic deviation of the presented from the expected word and different mechanisms involved in the processing of complete as compared to partial acoustic deviations. Most importantly, however, tonally and segmentally induced semantic violations were comparable. This suggests that listeners access tone and segmental information at a similar point in time and that both types of information play comparable roles during word processing in Cantonese.

Lexical activation during the recognition of Chinese characters: evidence against early phonological activation.

In two primed-naming experiments involving Chinese character recognition, one with native Mandarinspeaking subjects and another with native Cantonese-speaking subjects, we varied both the stimulus onset asynchrony (SOA) and the prime—target similarity along various lexical dimensions. Across both experiments, the results were as follows: (1) Relatively strong and reliable semantic priming appeared very early across various SOAs, and its onset was not affected by meaning precision, (2) either homophonic priming had negligible effects on target naming or the effects appeared relatively late (only at 57 msec), and (3) graphic inhibition was found across different SOAs. Since the same set of stimuli and procedure were adopted as those in the study of Perfetti and Tan (1998), the present findings raise questions about the reliability and validity of the results from their study that have been used to support the notion that phonology is a constitutive element of character recognition and precedes meaning access in the identification process. Instead, the present results suggest that phonology is optional for accessing meaning in Chinese character recognition among skilled adult readers.

ORTHOGRAPHIC AND PHONOLOGICAL ACTIVATION IN RECOGNIZING CHINESE CHARACTERS

This paper is a contribution to the study of whether visual contact with lexical units in any writing system necessarily arouses their corresponding phonological information. In two experiments it was investigated whether phonological information is automatically activated during the semantic processing of Chinese characters. In these experiments, both using a semantic-categorization task, subjects produced the same proportion of false positive categorization errors and showed the same decision latencies on homophone foils and their non-homophonic controls, thus indicating that phonological information does not seem to affect the semantic task. Experiment 2 further revealed that subjects made more errors and produced longer response times on graphemically similar foils than on the corresponding controls. The absence of phonological effects and the presence of clear effects of visual similarity for Chinese characters in semantic tasks can be taken to indicate that phonological information may not be automatically activated during the processing of meanings of Chinese characters. The present results also cast serious doubts on the hypothesis that phonological activation is a universal principle of lexical processing.

Lexical processing in a non-native language: Effects of language proficiency and learning strategy

In three experiments, native Chinese speakers were asked to use their native and non-native languages to read and translate Chinese words and to name pictures. In Experiment 1, four groups of subjects with various degrees of proficiency in their second language, English, participated. In Experiments 2 and 3, subjects were first asked to learn a list of words in a new language, French, using either Chinese words or pictures as media; then they performed the reading, naming, and translation tasks. All subjects performed better in reading words than in naming pictures, when responding in Chinese. When the response was in the non-native language (English or French), high-learning subjects were equally efficient in translation and picture-naming tasks. Low-learning subjects, however, performed better in either the translation or the picture-naming task, depending on their learning strategies. These results are consistent with the idea that both proficiency in a non-native language and the strategy for acquiring the language are main determinants for the pattern of lexical processing in that language.

Orthographic and Phonological Processing in Reading Chinese Text: Evidence From Eye Fixations

The use of orthographic and phonologic information in reading Chinese text was investigated using an eye-monitoring technique. The basic manipulation was to change a critical character in a short passage so that various combinations of orthographic and phonological information were altered. Patterns of disruption caused by different manipulations were compared in order to reveal the use of orthographic and phonological information from individual characters during reading for comprehension. Results showed that orthographic manipulations produced reliable and early disruption in first fixation duration at the target word position. In contrast, phonological effects were only found in the measure of a relatively late stage of processing (i.e., total reading time) at the target position, but not in early measures of processing. These results supported the position that it is orthography rather than phonology, which plays an early and dominant role in reading Chinese.

Involvement of left inferior frontal gyrus in sentence-level semantic integration

Using event-related functional MRI, we examined the involvement of the left inferior frontal gyrus (LIFG) in semantic integration in reading Chinese sentences. During scanning, Chinese readers read individually presented sentences and judged whether or not a sentence was semantically acceptable. Behaviorally, those sentences with a small degree of semantic violation were found to be more difficult to reject relative to sentences with a large degree of semantic violation, indicating that more semantic integration occurred in the former than in the latter condition. Direct contrast revealed significantly greater brain activity in the LIFG for sentences with a small violation, relative to those with a large violation, but no differences in any anterior temporal cortical areas between the two types of anomalous sentences. The results are in line with the idea that the LIFG plays a critical role in integrating individual word meanings to coherent sentence-level messages, but not with the idea that semantic integration depends on anterior temporal cortex in language comprehension.

LEFT-LATERALIZED N170 RESPONSE TO UNPRONOUNCEABLE PSEUDO BUT NOT FALSE CHINESE CHARACTERS-THE KEY ROLE OF ORTHOGRAPHY

A negative event-related potential (ERP) component, known as N170, can be readily recorded over the posterior left brain region when skilled readers are presented with visual words. This left-lateralized word-related N170 has been attributed either to linguistic processes, particularly phonological processing, or to the role of orthographic regularity, emphasizing a perceptual origin. This debate, however, is difficult to resolve in the context of alphabetic scripts because of the tight relations between orthography and phonology. In contrast, Chinese characters have arbitrary mappings between orthographic and sound forms, making it possible to tease apart these two properties of visual words. We therefore addressed this issue by examining ERP responses to Chinese characters and three types of structurally matched but unpronounceable stimuli: pseudo-characters, false-characters, and stroke combinations. A content-irrelevant color matching task was adopted to minimize potentially different top-down modulations across stimulus types. Results show that, relative to false-characters and stroke combinations, real- and pseudo-characters evoked greater N170 in the left posterior brain region. Critically, despite being unpronounceable, pseudo-characters produced the same amplitude and left-lateralized N170, just as real-characters. These results provide strong evidence that orthography rather than phonology serves as the main driver for the enhanced and left-lateralized N170 to visual words.

Early orthographic experience modifies both phonological awareness and on-line speech processing

Previous authors have shown that orthographic experience modifies phonological awareness, yet whether it also impacts on automatic speech processing has not been explored. In the present study, we replicated the effect of early orthographic experience on phonological awareness, and further demonstrated that on-line speech processing varied between readers coming from different literacy backgrounds. We measured phonological awareness and on-line speech processing by a sound matching and a primed shadowing task, respectively. Participants were Cantonese-Chinese speakers who had learned only logographic characters for their Chinese reading, and those who had learned both characters and alphabetic Pinyin. We found evidence of phoneme-level analysis in both sound matching and primed shadowing only in the latter group. This finding suggests an active role of orthographic experience in shaping phonological awareness and the representation subserving day-to-day speech communication.

ERP correlates of pre-attentive processing of Cantonese lexical tones: The effects of pitch contour and pitch height

The pre-attentive processing of Cantonese tones was studied with an auditory passive oddball paradigm. Event-related potentials to standard and deviant auditory stimuli were recorded as participants watched a silent movie attentively. The standards and deviants differed in either pitch level or pitch contour. Mismatch negativity (MMN) and P3a were elicited by all types of deviant tones, suggesting that lexical tone was processed pre-attentively. In addition, the size and latency of MMN were sensitive to the size of pitch level change, while the latency of P3a captured the presence of pitch contour change. These results indicate that pitch contour and pitch height are two important dimensions in sensory processing of lexical tones.