Qi Dong

There are great individual differences in learning abilities, but their neural bases, especially among normal populations, are not well understood. Using functional magnetic resonance imaging and a training paradigm, the present study investigated individual differences in cerebral asymmetry in fusiform regions when processing a new writing system and their correlation to subsequent visual character learning. Twelve Chinese adults underwent a 2-week training to learn 120 Korean characters and they were scanned before and after the training. Results showed that left-hemispheric dominance during the pretraining task was predictive of better posttraining performance. These results have significant implications for our understanding of the neural basis of language learning, especially in terms of individual differences. © 2006 Massachusetts Institute of Technology.

Using the ER-fMRI technique, the present study was designed to investigate the neural substrates of language switching among second-language learners. Twelve Chinese college students who were learning English were scanned when they performed language switching tasks. Compared to non-switching conditions, language switching elicited greater activation in the right superior prefrontal cortex, left middle and superior frontal cortex, and right middle cingulum and caudate. When the direction of switching was considered, forward switching, but not backward switching, activated several brain regions related to executive functions relative to non-switching conditions. These results suggest that neural correlates of language switching differ depending on the direction of the switch and that there does not seem to be a specific brain area acting as a "language switch". © 2006.

Previous studies have identified the critical role of the left fusiform cortex in visual word form processing, learning, and memory. However, this so-called visual word form area's other functions are not clear. In this study, we used fMRI and the subsequent memory paradigm to examine whether the putative VWFA was involved in the processing and successful memory encoding of faces as well as words. Twenty-two native Chinese speakers were recruited to memorize the visual forms of faces and Chinese words. Episodic memory for the studied material was tested 3. h after the scan with a recognition test. The fusiform face area and the VWFA were functionally defined using separate localizer tasks. We found that, both within and across subjects, stronger activity in the VWFA was associated with better recognition memory of both words and faces. Furthermore, activation in the VWFA did not differ significantly during the encoding of faces and words. Our results revealed the important role of the so-called VWFA in face processing and memory and supported the view that the left mid-fusiform cortex plays a general role in the successful processing and memory of different types of visual objects. © 2010 Elsevier Inc.

Existing cognitive and neural imaging studies have suggested a frontoparietal network of multiple, cooperative components for verbal working memory. We used functional MRI to investigate whether this neural network is also involved in the processing of second language by nonfluent bilinguals. Twelve native Chinese speakers who had limited English proficiency were scanned while performing working memory tasks in Chinese and English. They were asked to make judgment continuously whether the word presented on the screen was semantically related to another word presented two words earlier. On a different task, they were asked to make judgment whether the target word rhymed with the other word. A naming and judgment task in each language was adopted to control for the visual process, initial lexical process, and motor responses. Behavioral data showed that subjects performed better at tasks in their native language than in English. Imaging results showed that all working memory tasks in both L1 and L2 elicited a very similar pattern of left-hemisphere-dominated activation in the dorsolateral prefrontal cortex, pars opercularis region, pars triangularis region, precentral cortex, and parietal lobule. Consistent with the behavioral data, the volume of activation in the left opercularis region, left parietal lobule, and right precentral region was greater for L2 than for L1. These results suggest that working memory in L1 and L2 is mediated by a unitary neural system, which is capable of recruiting surrounding cortical resources to meet the increased computational demand caused by low L2 proficiency. © 2004 Elsevier Inc. All rights reserved.

© 2013, Springer-Verlag Berlin Heidelberg.Overweight and obesity are rapidly becoming a central public health challenge around the world. Previous studies have suggested that elevated Body Mass Index might be associated with structural changes in both gray and white matter, but this association is still not well understood. The present study aimed to investigate the relationship between BMI and brain structure with a relatively large sample of young adults in a small age range. Voxel-based morphometry results showed significant negative correlations between BMI and gray-matter volumes in the midcingulate cortex, left orbital frontal cortex, and left ventromedial prefrontal cortex. There was also a significant negative correlation between BMI and white matter integrity as indexed by fractional anisotropy in bilateral cingulum. Further tractography analysis showed a significant negative correlation between BMI and the number of fibers passing the MCC region. Regression analysis showed that gray matter and white matter in these regions both contributed to the variance of BMI. These results remained significant even when analysis was restricted to the subjects with normal weights. Finally, we found that decision-making ability mediated the association between the structure of the MCC and BMI. These results shed light on the structural neural basis of weight variations.

Mathematical cognition is one of the most important cognitive functions of human beings. The latest brain and cognitive research have shown that mathematical cognition is a system with multiple components and subsystems. It has phylogenetic root, also is related to ontogenetic development and learning, relying on a large-scale cerebral network including parietal, frontal and temporal regions. Especially, the parietal cortex plays an important role during mathematical cognitive processes. This indicates that language and visuospatial functions are both key to mathematical cognition. All of those advances have important implications for basic mathematical education.

Biopiracy represents not merely the exploitation of biological and genetic resources, but a systematic form of epistemic colonialism. This article examines traditional knowledge governance through the lens of epistemic justice and decolonization, integrating Fricker’s theory of epistemic injustice, Kuokkanen’s concept of relational sovereignty, and Santos’s epistemology of the South to construct a three-stage analytical model encompassing “biopiracy, epistemicide, and knowledge sovereignty reconstruction.” Through comparative analysis of institutional innovations in India, Brazil, and South Africa, the study reveals structural exclusion mechanisms inherent in Western property paradigms toward indigenous knowledge while demonstrating fundamental flaws in benefit-sharing mechanisms under the Convention on Biological Diversity framework. The article argues that sustainable knowledge governance must be grounded in epistemic pluralism, achieved through restoring indigenous communities’ epistemic autonomy, recognizing the normative value of relational sovereignty, and establishing polycentric knowledge ecosystems to facilitate a paradigmatic shift from colonial knowledge orders to post-Western knowledge systems.