Guangdong Key Laboratory of Biomedical Information Detection and Ultrasound Imaging

Shenzhen, China

Guangdong Key Laboratory of Biomedical Information Detection and Ultrasound Imaging

Shenzhen, China
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Kwok V.P.Y.,Shenzhen Institute of Neuroscience | Dan G.,Shenzhen University | Dan G.,Guangdong Key Laboratory of Biomedical Information Detection and Ultrasound Imaging | Yakpo K.,University of Hong Kong | And 10 more authors.
Frontiers in Human Neuroscience | Year: 2017

The neural systems of lexical tone processing have been studied for many years. However, previous findings have been mixed with regard to the hemispheric specialization for the perception of linguistic pitch patterns in native speakers of tonal language. In this study, we performed two activation likelihood estimation (ALE) meta-analyses, one on neuroimaging studies of auditory processing of lexical tones in tonal languages (17 studies), and the other on auditory processing of lexical information in non-tonal languages as a control analysis for comparison (15 studies). The lexical tone ALE analysis showed significant brain activations in bilateral inferior prefrontal regions, bilateral superior temporal regions and the right caudate, while the control ALE analysis showed significant cortical activity in the left inferior frontal gyrus and left temporoparietal regions. However, we failed to obtain significant differences from the contrast analysis between two auditory conditions, which might be caused by the limited number of studies available for comparison. Although the current study lacks evidence to argue for a lexical tone specific activation pattern, our results provide clues and directions for future investigations on this topic, more sophisticated methods are needed to explore this question in more depth as well. © 2017 Kwok, Dan, Yakpo, Matthews, Fox, Li and Tan.

Yang Y.,Shenzhen Institute of Neuroscience | Jia F.,Shenzhen Institute of Neuroscience | Siok W.T.,Shenzhen Institute of Neuroscience | Siok W.T.,University of Hong Kong | And 3 more authors.
Neuroscience | Year: 2017

Persistent developmental stuttering is a neurologically based speech disorder associated with cognitive-linguistic, motor and emotional abnormalities. Previous studies investigating the relationship between anxiety and stuttering have yielded mixed results, but it has not yet been examined whether anxiety influences brain activity underlying stuttering. Here, using functional magnetic resonance imaging (fMRI), we investigated the functional connectivity associated with state anxiety in a syllable repetition task, and trait anxiety during rest in adults who stutter (N = 19) and fluent controls (N = 19). During the speech task, people who stutter (PWS) showed increased functional connectivity of the right amygdala with the prefrontal gyrus (the left ventromedial frontal gyrus and right middle frontal gyrus) and the left insula compared to controls. During rest, PWS showed stronger functional connectivity between the right hippocampus and the left orbital frontal gyrus, and between the left hippocampus and left motor areas than controls. Taken together, our results suggest aberrant bottom-up and/or top-down interactions for anxiety regulation, which might be responsible for the higher level of state anxiety during speech and for the anxiety-prone trait in PWS. To our knowledge, this is the first study to examine the neural underpinnings of anxiety in PWS, thus yielding new insight into the causes of stuttering which might aid strategies for the diagnosis and treatment of stuttering. © 2017 IBRO

Ge J.,Peking University | Peng G.,Chinese University of Hong Kong | Peng G.,CAS Shenzhen Institutes of Advanced Technology | Lyu B.,Peking University | And 7 more authors.
Proceedings of the National Academy of Sciences of the United States of America | Year: 2015

How is language processed in the brain by native speakers of different languages? Is there one brain system for all languages or are different languages subserved by different brain systems? The first view emphasizes commonality, whereas the second emphasizes specificity. We investigated the cortical dynamics involved in processing two very diverse languages: a tonal language (Chinese) and a nontonal language (English). We used functional MRI and dynamic causal modeling analysis to compute and compare brain network models exhaustively with all possible connections among nodes of language regions in temporal and frontal cortex and found that the information flow from the posterior to anterior portions of the temporal cortex was commonly shared by Chinese and English speakers during speech comprehension, whereas the inferior frontal gyrus received neural signals from the left posterior portion of the temporal cortex in English speakers and from the bilateral anterior portion of the temporal cortex in Chinese speakers. Our results revealed that, although speech processing is largely carried out in the common left hemisphere classical language areas (Broca's and Wernicke's areas) and anterior temporal cortex, speech comprehension across different language groups depends on how these brain regions interact with each other. Moreover, the right anterior temporal cortex, which is crucial for tone processing, is equally important as its left homolog, the left anterior temporal cortex, in modulating the cortical dynamics in tone language comprehension. The current study pinpoints the importance of the bilateral anterior temporal cortex in language comprehension that is downplayed or even ignored by popular contemporary models of speech comprehension. © 2015, National Academy of Sciences. All rights reserved.

Xu M.,Shenzhen University | Xu M.,Guangdong Key Laboratory of Biomedical Information Detection and Ultrasound Imaging | Yang J.,Guangdong University of foreign Studies | Siok W.T.,University of Hong Kong | And 2 more authors.
Journal of Neurolinguistics | Year: 2015

Developmental dyslexia is a neurological condition characterized by unexpected low reading performance in people with normal intelligence and typical schooling. One prominent theory posits that dyslexic children fail to establish left-hemispheric dominance of visual representations and visual-phonological/meaning integration of printed words and thus exhibit an atypical lateralization of lexical processing. Behavioral, electrophysiological, histological, and morphological imaging studies examining this hemispheric asymmetry have generated conflicting evidence; however, it remains possible that dyslexics have impaired functional lateralization of language processes without a structural correlate. Here, using functional magnetic resonance imaging (fMRI) and a phonological task with working memory, we found distinct hemispheric asymmetry differences between dyslexic and normal children in brain regions subserving the storage and manipulation of phonological information in phonological working memory. Further, the degree of leftward asymmetry correlates positively with reading performance. Thus, the language impairments in dyslexic children appear related to a reduced dominance of the left hemisphere in phonological language functions, which offers clues into the biological dysfunction and possible remediation of developmental dyslexia. © 2014 The Authors.

Shi Y.,Shanghai Maritime University | Zeng W.,Shanghai Maritime University | Wang N.,Shenzhen University | Wang N.,Guangdong Key Laboratory of Biomedical Information Detection and Ultrasound Imaging
Computer Methods and Programs in Biomedicine | Year: 2017

Background and Objective With the rapid development of big data, the functional magnetic resonance imaging (fMRI) data analysis of multi-subject is becoming more and more important. As a kind of blind source separation technique, group independent component analysis (GICA) has been widely applied for the multi-subject fMRI data analysis. However, spatial concatenated GICA is rarely used compared with temporal concatenated GICA due to its disadvantages. Methods In this paper, in order to overcome these issues and to consider that the ability of GICA for fMRI data analysis can be improved by adding a priori information, we propose a novel spatial concatenation based GICA with reference (SCGICAR) method to take advantage of the priori information extracted from the group subjects, and then the multi-objective optimization strategy is used to implement this method. Finally, the post-processing means of principal component analysis and anti-reconstruction are used to obtain group spatial component and individual temporal component in the group, respectively. Results The experimental results show that the proposed SCGICAR method has a better performance on both single-subject and multi-subject fMRI data analysis compared with classical methods. It not only can detect more accurate spatial and temporal component for each subject of the group, but also can obtain a better group component on both temporal and spatial domains. Conclusions These results demonstrate that the proposed SCGICAR method has its own advantages in comparison with classical methods, and it can better reflect the commonness of subjects in the group. © 2017 Elsevier B.V.

Kwok V.P.Y.,University of Hong Kong | Dan G.,Shenzhen University | Dan G.,Guangdong Key Laboratory of Biomedical Information Detection and Ultrasound Imaging | Yakpo K.,University of Hong Kong | And 3 more authors.
Journal of Neurolinguistics | Year: 2016

Previous neuroimaging research on cognitive processing of speech tone has generated dramatically different patterns of findings. Even at the basic perception level, brain mapping studies of lexical tones have yielded inconsistent results. Apart from the data inconsistency problem, experimental materials in past studies of tone perception carried little or minimal lexical semantics, an important dimension that should not be dispensed with because speech tones serve to distinguish lexical meanings. The present study sought to examine the neural correlates of the perception of speech tone using lexically meaningful experimental stimuli. A simple lexical tone perception task was devised in which native Mandarin speakers were asked to judge whether or not the two syllables of an auditorily presented Chinese bisyllabic word had the same tone. We selected bisyllabic words as experimental stimuli because Chinese monosyllables often convey little or very vague meanings due to rampant homophony. We found that the left inferior frontal gyrus, the right middle temporal gyrus and bilateral superior temporal gyri are responsible for basic perception of linguistic pitches. Our interpretation of the data sees the left superior temporal gyrus as engaged in primary acoustic analysis of the auditory stimuli, while the right middle superior temporal gyrus and the left inferior frontal region are involved in both tonal and semantic processing of the language stimuli. © 2015 Elsevier Ltd.

Ansaldo U.,University of Hong Kong | Lai J.,University of Hong Kong | Jia F.,University of Hong Kong | Siok W.T.,University of Hong Kong | And 3 more authors.
Journal of Neurolinguistics | Year: 2015

In this study we investigate how the human brain processes small clauses and finite clauses. Small clauses are instances of 'simpler' syntax in the sense that they do not involve operations such as Move and Tense, and have been argued to represent an earlier stage of syntactic evolution before the development of fully-fledged syntax (Bickerton, 1990; Jackendoff 2010; Uriagereka, 2008). Understanding how the brain processes instances of different levels of syntactic complexity may further our understanding of (i) the analytical functions of specific brain regions, and (ii) the distribution of labor in the interpretation or different levels of syntax. To pursue this hypothesis, we ask whether small clauses require different analytical processes than regular syntax. This report provides evidence that they do. In an fMRI study of syntactic processing in a group of Mandarin speakers, small clauses showed greater activation of areas involved in semantic processing. In addition, both small and finite clauses showed substantial activation of areas implicated in syntactic and semantic processing, including significant RH activation. © 2014 The Authors.

Xu M.,Shenzhen University | Xu M.,Guangdong Key Laboratory of Biomedical Information Detection and Ultrasound Imaging | Xu M.,University of Hong Kong | Wang T.,Shenzhen University | And 8 more authors.
Human Brain Mapping | Year: 2015

Past neuroimaging studies have focused on identifying specialized functional brain systems for processing different components of reading, such as orthography, phonology, and semantics. More recently, a few experiments have been performed to look into the integration and interaction of distributed neural systems for visual word recognition, suggesting that lexical processing in alphabetic languages involves both ventral and dorsal neural pathways originating from the visual cortex. In the present functional magnetic resonance imaging study, we tested the multiple pathways model with Chinese character stimuli and examined how the neural systems interacted in reading Chinese. Using dynamic causal modeling, we demonstrated that visual word recognition in Chinese engages the ventral pathway from the visual cortex to the left ventral occipitotemporal cortex, but not the dorsal pathway from the visual cortex to the left parietal region. The ventral pathway, however, is linked to the superior parietal lobule and the left middle frontal gyrus (MFG) so that a dynamic neural network is formed, with information flowing from the visual cortex to the left ventral occipitotemporal cortex to the parietal lobule and then to the left MFG. The findings suggest that cortical dynamics is constrained by the differences in how visual orthographic symbols in writing systems are linked to spoken language. © 2015 Wiley Periodicals, Inc.

Zhang L.,Shenzhen University | Zhang L.,National Regional Key Technology Engineering Laboratory for Medical Ultrasound | Zhang L.,Guangdong Key Laboratory of Biomedical Information Detection and Ultrasound Imaging | Kong H.,Massachusetts Institute of Technology | And 9 more authors.
Bio-Medical Materials and Engineering | Year: 2014

This paper proposes a method to segment the cytoplasm in cervical cell images using graph cut-based algorithm. First, the A* channel in CIE LAB color space is extracted for contrast enhancement. Then, in order to effectively extract cytoplasm boundaries when image histograms present non-bimodal distribution, Otsu multiple thresholding is performed on the contrast enhanced image to generate initial segments, based on which the segments are refined by the multi-way graph cut method. We use 21 cervical cell images with non-ideal imaging condition to evaluate cytoplasm segmentation performance. The proposed method achieved a 93% accuracy which outperformed state-of-the-art works. © 2014 - IOS Press and the authors. All rights reserved.

Zhang L.,Shenzhen University | Zhang L.,National Regional Key Technology Engineering Laboratory for Medical Ultrasound | Zhang L.,Guangdong Key Laboratory of Biomedical Information Detection and Ultrasound Imaging | Kong H.,Massachusetts Institute of Technology | And 11 more authors.
Cytometry Part A | Year: 2014

Current automation-assisted technologies for screening cervical cancer mainly rely on automated liquid-based cytology slides with proprietary stain. This is not a cost-efficient approach to be utilized in developing countries. In this article, we propose the first automation-assisted system to screen cervical cancer in manual liquid-based cytology (MLBC) slides with hematoxylin and eosin (H&E) stain, which is inexpensive and more applicable in developing countries. This system consists of three main modules: image acquisition, cell segmentation, and cell classification. First, an autofocusing scheme is proposed to find the global maximum of the focus curve by iteratively comparing image qualities of specific locations. On the autofocused images, the multiway graph cut (GC) is performed globally on the a* channel enhanced image to obtain cytoplasm segmentation. The nuclei, especially abnormal nuclei, are robustly segmented by using GC adaptively and locally. Two concave-based approaches are integrated to split the touching nuclei. To classify the segmented cells, features are selected and preprocessed to improve the sensitivity, and contextual and cytoplasm information are introduced to improve the specificity. Experiments on 26 consecutive image stacks demonstrated that the dynamic autofocusing accuracy was 2.06 μm. On 21 cervical cell images with nonideal imaging condition and pathology, our segmentation method achieved a 93% accuracy for cytoplasm, and a 87.3% F-measure for nuclei, both outperformed state of the art works in terms of accuracy. Additional clinical trials showed that both the sensitivity (88.1%) and the specificity (100%) of our system are satisfyingly high. These results proved the feasibility of automation-assisted cervical cancer screening in MLBC slides with H&E stain, which is highly desirable in community health centers and small hospitals. © 2013 International Society for Advancement of Cytometry.

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