PROJECTS
The left middle frontal gyrus: How is it related to Chinese reading?
This project aims to elucidate 1) the neural networks for the orthographic, phonological and semantic constituents of Chinese and English reading, 2) how language learning experience shapes the brain structure and functions, and 3) the cognitive functions subserved by the left middle frontal region (LMFG) that are pertinent to reading. Our previous studies published in Nature, PNAS and Current Biology revealed significant variation between the neural substrates of impaired reading in Chinese and English. A central finding was that Chinese dyslexics had reduced activation relative to controls in the left middle frontal gyrus (LMFG) during reading processing but the two groups did not differ in the left temporoparietal region, which has been found deficient in alphabetic dyslexics and is believed to be responsible for rule-based phonological processing. We speculate that the LMFG may be responsible for the mapping of orthography-to-phonology and orthography-to-semantics and the coordination and integration of visuospatial information with linguistic (phonology and meaning) information.
Cortical language function protection of aphasic patients
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This project aims to analyze lesion-behavior mapping in Chinese aphasic patients using anatomical, diffusion and resting-state functional magnetic resonance imaging. Chinese neurosurgeons used to follow the Western practice of protecting Broca’s and Wernicke’s areas during brain surgery based on the assumption that the language network is universal across cultures. Since the publication of our work in 2004, some neurosurgeons have become aware of the unique role of the LMFG in Chinese reading processing and argued that language-specific brain maps should be adopted for better brain surgery planning (e.g., Feng et al., 2006; Shang et al., 2013; Zhang et al., 2008). For example, a group of neurosurgeons at Shanghai’s Huashan Hospital performed awake surgery and intraoperative language mapping on patients with glioma to map their language regions. The neurosurgeons reported that an additional brain area, the LMFG, was unique in Chinese production and that the language maps for Chinese and English are different. Importantly, with the use of this Chinese-specific language map, the incidence of postoperative language disorders had significantly reduced to 4.5% (in their study based on 66 patients) (Wu et al., 2015, HBM). The findings of this project will serve important theoretical and clinical purposes: 1) inform whether the nature and types of aphasia vary across languages, 2) reveal which brain-behavior metrics better correlate with language deficits, and 3) find out the best assessment protocol that can quickly unveil their stroke-induced language deficits.
Cognitive and brain mechanisms underlying typical and atypical language and reading processing
This project aims to 1) examine the cognitive and brain mechanisms underlying normal and atypical language and reading development, 2) study the comorbidity rate of the two types of disorders, and 3) compare the effectiveness of various reading remediation approaches including phonological training approach and other approaches that emphasize on visual, orthographic, working memory or motor skills. We will use a comprehensive battery of tasks including language and reading ability tests, phonological processing, visuo-orthographic skills, working memory functions (visuospatial working memory, phonological working memory, and executive control functions such as selection and switching) and motor skills will be used to measure children’s general language and reading functions. Their brain scans during language and reading processing will be acquired using MRI and fMRI.
Language development in children with autism spectrum condition (ASC)
The project aims to: (1) illustrate how Chinese autistic individuals differ from neurotypicals in terms of literacy development; (2) investigate what factors contribute to Chinese literacy development in autism; (3) understand why autistic individuals perform distinctly in reading words and reading meanings from the perspective of the brain; (4) seek possible neuro-markers in autism’ language and cognitive system. The project will help contribute to the understanding of the autistic population in Hong Kong in terms of their language and brain development. It uses multimodal neuroscience techniques including Electroencephalography (EEG), functional Magnetic Resonance Imaging (fMRI), and an integrated EEG and eye-tracking approach to probe into the brain function of Chinese ASC. Using multimodal neuroscience techniques helps obtain both high temporal (EEG) and spatial resolution (fMRI).