Biomedical subjects

Chuansheng Chen

Publications and source records attributed to Chuansheng Chen.

11 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

Numerical distance effect in the N240 component in a number-matching task.

The event-related potential technique was used to investigate the time course and scalp-potential topography for the numerical distance effect in a number-matching task. Twenty undergraduates judged whether a number matched or did not match another number presented 1.5 s earlier. Compared with number pairs with a 'small' numerical distance (distance=1), number pairs with a 'large' numerical distance (greater than 2) showed a longer latency and a greater positive amplitude in the N240 component. This numerical distance effect was limited to fronto-central electrodes. These results were discussed in terms of the neural bases of the numerical distance effect during the automatic processing of numbers.

Adult↗

PubMed2006

Event-related potentials of single-digit addition, subtraction, and multiplication.

This study compared the event-related potentials elicited by single-digit addition, subtraction, and multiplication problems. With a delayed verification paradigm, 18 Chinese undergraduates were first asked to solve the arithmetic problems that were presented visually for 200 ms and, after 1.5 s, to judge whether a presented solution was correct or not. Results showed that, compared to addition and subtraction, multiplication elicited a greater N300 at the left frontal electrodes peaking around 320 ms (in the interval between 275 and 334 ms after the onset of the arithmetic problem). To control for the confounding effects of task difficulty and solution size, comparisons were further made between "large" addition problems (with sums between 11 and 17) and "small" multiplication problems (with products between 6 and 24). Similar results were obtained (i.e., a significant difference between addition and multiplication in the N300 component between 296 and 444 ms). Source analyses demonstrated that a single dipole in the left anterior brain areas could have contributed to the topographies of the difference waveforms ("multiplication-addition", "multiplication-subtraction", and "'small' multiplication-'large' addition"). These results are interpreted in terms of the greater reliance on phonological processing for the retrieval of multiplication facts than for the retrieval of addition and subtraction facts.

Adolescent↗

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

Dissociation in the neural basis underlying Chinese tone and vowel production.

Neuropsychologists have debated over whether the processing of segmental and suprasegmental units involves different neural mechanisms. Focusing on the production of Chinese lexical tones (suprasegmental units) and vowels (segmental units), this study used the adaptation paradigm to investigate a possible neural dissociation for tone and vowel production. Ten native Chinese speakers were asked to name Chinese characters and pinyin (Romanized phonetic system for Chinese language) that varied in terms of tones and vowels. fMRI results showed significant differences in the right inferior frontal gyrus between tone and vowel production (more activation for tones than for vowels). Brain asymmetry analysis further showed that tone production was less left-lateralized than vowel production, although both showed left-hemisphere dominance.

Adult↗

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

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↗

PubMed2003

Understanding depressed mood in the context of a family-oriented culture.

This study examined the contribution of individual and family variables to depressive symptoms among youths in a family-centered culture. Participants were 262 Mexican adolescents (mean age = 15.9 years). At the individual level, gender (being female) and higher levels of perceived stressfulness of life events and ruminative coping style were correlated with higher frequency of depressive symptoms. At the family level, higher levels of perceived parental warmth and acceptance and parental monitoring were correlated with lower levels of depressed mood, whereas higher levels of parent-adolescent conflict were associated with greater frequency of depressive symptoms. Regression analyses confirmed our prediction that both individual factors (gender, ruminative coping) and family factors (parental warmth and parental monitoring) would make unique contributions to depressive symptoms. The model comprised of individual and family variables accounted for 50% of the variance in depressed mood. Moreover, parental warmth and acceptance attenuated the impact of ruminative coping style on adolescents' depressive symptomatology. Findings are discussed in relation to previous research on adolescents in another family-centered culture (China), and directions for future research are proposed.

Adaptation, Psychological↗

PubMed2002

The nature of adolescents' relationships with their "very important" nonparental adults.

As part of a larger program of research on the nature of adolescents' relationships with very important nonparental adults (hereafter referred to as "VIPs"), a community sample of 243 eleventh graders (mean age = 16.6 years) was surveyed, and a subgroup of 55 adolescents and their VIPs were interviewed about the nature and quality of their relationships. Results showed that (a) adolescent-VIP relationships were a normative component of adolescent development, not a result of problems in adolescents' lives; (b) adolescent-VIP relationships were generally of high quality (e.g., high support, low conflict, and high mutuality); (c) there were significant differences between kin and nonkin VIPs in terms of the duration of relationships and frequency of contact, but not in the quality of relationships; and (d) VIPs whom adolescents designated as extremely important were distinguished from other VIPs in terms of providing a higher level of social support and a higher frequency of contact. Theoretical and practical implications of these findings are discussed.

Adolescent↗