研究方向：語言短期記憶
主題：The interaction of phonological and orthographic similarity in verbal short-term memory of Chinese characters
說明：
Previous literature on verbal short-term memory (STM) for alphabetic languages indicates that phonologically distinct materials are maintained in phonological codes while phonologically similar materials might rely on additional orthographic codes. In contrast, we found that only orthographic similarity (i.e., sharing common radicals on the right side of characters), but not visual similarity (i.e., sharing overall stroke configurations), had an effect on verbal STM for Chinese materials regardless the phonological similarity of list items. To determine whether the same or distinct neuronal mechanisms support the retention of phonologically dissimilar and similar lists, we applied the functional magnetic resonance imaging (fMRI) technique to identify the brain regions underlying the orthographic and visual representation involved in verbal and nonverbal STM, respectively. Preliminary results demonstrated that the retention of Chinese orthographic representation was supported by the jointed contribution from language-specific and nonverbal visual-spatial processing.
主題：The behavioral and neural correlates of orthographic lexicon and orthographic buffer in Chinese writing
說明：
Previous literature on writing has demonstrated a double dissociation of the underlying functional and neuronal mechanisms between the orthographic lexicon and the graphemic buffer in alphabetic languages. Specifically, the frequency of to-be-writtten stimuli correlated with the processing of the orthographic lexicon situated in the left fusiform gyrus and left inferior frontal junction, while the letter length of the to-be-written stimuli correlated with the processing of the graphemic buffer situated in the left superior frontal sulcus and left superior parietal lobule. Such dissociation has not been explicitly explored in non-alphabetic languages. In the present study, we aimed to identify the neural correlates of the orthographic lexicon and buffer in writing Chinese characters via functional magnetic resonance imaging (fMRI). The experiment was conducted by a mental writing task and a recognition task on Chinese characters whose frequency and stroke numbers were manipulated. It was found that characters with low frequency were associated with higher activation in the left fusiform gyrus than characters with high frequency in the two tasks, suggesting this region to be responsible for the orthographic lexicon that represents the knowledge of character forms. It was also found that character stroke numbers correlated with the activation in the left middle frontal gyrus and left angular gyrus only in the mental writing task, suggesting this region to be responsible for the orthographic buffer that represents the knowledge of stroke sequences in written production. These results revealed the functional and anatomical dissociation between the orthographic lexicon and buffer in writing Chinese characters.