Biomedical subjects

Gui Xue

Publications and source records attributed to Gui Xue.

7 recordsLinked to original sources

PubMed2006

Sex determines the neurofunctional predictors of visual word learning.

This study used functional MRI and an artificial language training paradigm to explore sex differences in the processing of a new writing system and how sex determines the optimal neural resource recruitment for visual word learning. Results indicated that males and females achieved equal learning outcome, and their learning curve followed a similar power function. They also showed similar overall activation in the fusiform cortex, a region that has been associated with visual word processing. Despite the absence of sex differences in averaged behavioral performance and neural activation, males and females were found to have different neural predictors of visual word learning. As predicted, left-lateralized fusiform activation predicted visual word learning for males, but not for females, whereas bilateral fusiform activation predicted visual word learning for females, but not males. These results suggest that male and female brains operate differently to achieve the best performance in visual word learning. The individual-differences approach adopted in the present study provides a new and useful perspective to sex differences.

Adult↗

PubMed2006

Neural substrates for forward and backward recitation of numbers and the alphabet: a close examination of the role of intraparietal sulcus and perisylvian areas.

Despite numerous studies on the neural basis of numerical processing, few studies have examined the neural substrates of one of the most basic numerical processing-number sequence recitation. The present study used fMRI to investigate neural substrates of number sequence recitation, focusing on the intraparietal sulcus (IPS) and perisylvian areas. This study used a 2 (number versus alphabet) x 2 (forward versus backward recitation) design. 12 Chinese undergraduates were asked to recite overtly but gently numerical and alphabetical sequences forward and backward. Results showed that, for both numerical and alphabetic sequences, the left IPS was activated when performing backward recitation, but not when performing forward recitation. In terms of perisylvian areas, all four tasks elicited activation in bilateral superior temporal gyrus and inferior frontal gyrus, but forward recitation elicited greater activation in the left posterior superior temporal gyrus than did backward recitation, whereas backward recitation elicited greater activation in the left inferior frontal gyrus than did forward recitation. These results suggest that forward recitation of numbers and the alphabet is typically based on verbal processing of numbers implemented in the perisylvian area, whereas backward recitation would likely require additional neural resources in the IPS.

Adolescent↗

PubMed2006

Language experience shapes fusiform activation when processing a logographic artificial language: an fMRI training study.

The significant role of the left midfusiform cortex in reading found in recent neuroimaging studies has led to the visual word form area (VWFA) hypothesis. This hypothesis suggests that years of experience reading native language change the visual expertise of this region to be especially sensitive to the visual form of native language. The present study aimed at testing this hypothesis by exploring the role of language experience in shaping the fusiform activation. We designed a logographic artificial language (LAL) using the visual form and pronunciation of Korean Hangul characters (but their correspondence was shuffled) and assigning arbitrary meanings to these characters. Twelve native Chinese Mandarin speakers (6 male and 6 female, 18 to 21 years old) with no prior knowledge of Korean language were trained in the visual form of these characters for 2 weeks, followed by 2 weeks each of phonological and semantic training. Behavioral data indicated that training was effective in increasing the efficiency of visual form processing and establishing the connections among visual form, sounds, and meanings. Imaging data indicated that at the pre-training stage, subjects showed stronger activation in the fusiform regions for LAL than for Chinese across both one-back visual matching task and the passive viewing task. Visual form training significantly decreased the activation of bilateral fusiform cortex and the left inferior occipital cortex, whereas phonological training increased activation in these regions, and the right fusiform remained more active after semantic training. Increased activations after phonological and semantic training were also evident in other regions involved in language processing. These findings thus do not seem to be consistent with the visual-expertise-induced-sensitivity hypothesis about fusiform regions. Instead, our results suggest that visual familiarity, phonological processing, and semantic processing all make significant but different contributions to shaping the fusiform activation.

Adolescent↗

PubMed2006

Cerebral asymmetry in the fusiform areas predicted the efficiency of learning a new writing system.

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.

Adolescent↗

PubMed2005

Cerebral asymmetry in children when reading Chinese characters.

This study examined cerebral asymmetry, especially in the hierarchical visual system, when reading Chinese characters. Twelve right-handed Chinese children (mean age = 11.6 years) were scanned while performing semantic and phonological tasks. Strong leftward asymmetry was found in the left inferior frontal cortex (BA44/45/47), the parietal lobule (BA40), and the cingulate cortex (BA24/32). In the visual system, we found significant left-hemispheric dominance in the fusiform cortex (BA19/37), but no asymmetry was found in the primary visual cortex (BA17/18). The differential results for the primary visual cortex versus high-order visual cortex (i.e., the fusiform cortex) are discussed in terms of the contribution of the logographic nature of Chinese characters to the asymmetry pattern in the hierarchical visual system.

Brain Mapping↗

PubMed2004

An fMRI study with semantic access in low proficiency second language learners.

Brain activity was measured with fMRI in twelve 10- to 12-year-old Chinese children who began learning English when they were 8 years old in order to find out whether there is a common or a distinct neural semantic system for native language (L1) and second language (L2) in low proficiency bilingual subjects. Although they performed less well in L2 in the semantic decision task administered during fMRI measurement, these subjects showed similar robust activation, for both languages, in brain areas involved in semantic processing (e.g. the left inferior frontal cortex). Within-subject and group analyses revealed no significant difference in the activation patterns for L1 and L2 in these regions. These results suggest that at least at single-word level, there are shared neural substrates for semantic processing of L1 and L2 even when one is at a very low L2 proficiency level.

Brain↗

PubMed2004

Mapping of verbal working memory in nonfluent Chinese-English bilinguals with functional MRI.

Existing cognitive and neural imaging studies have suggested a frontoparietal network of multiple, cooperative components for verbal working memory (WM). We used functional MRI to investigate whether this neural network is also involved in the processing of second language by nonfluent bilinguals. Twelve (five males, seven females) 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 (i.e., the semantic tasks) another word presented two words earlier. On a different task (i.e., the phonological tasks), 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 (Chinese, L1) than in English (L2). 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 (i.e., frontoparietal region), which is capable of recruiting surrounding cortical resources to meet the increased computational demand caused by low L2 proficiency.

Adult↗