Bilinguals have different hemispheric lateralization in visual word processing from monolinguals

Open URL: http://csjarchive.cogsci.rpi.edu/Proceedings/2011/Previous studies showed reduced hemispheric asymmetry (HA) in visual tasks like face perception in bilinguals compared with monolinguals, suggesting experience in reading one or two languages could be a modulating factor. We examined whether HA differences in visual tasks can also be observed in bilinguals with different language backgrounds. We compared the behavior of three groups in a tachistoscopic English word sequential matching task: English monolinguals (alphabetic monolinguals, A-Ms), bilinguals with an alphabetic-L1 and English-L2 (alphabetic-alphabetic bilinguals, AA-Bs), and bilinguals with Chinese-L1 and English-L2 (logographic-alphabetic bilinguals, LA-Bs). The results showed AA-Bs had a stronger left hemispheric lateralization than A-Ms and LA-Bs, suggesting different language learning experiences can influence visual words processing. Our computational model could explain this effect, based on a perceptual HA theory; the modeling data suggested this difference may be due to the differences in both participants’ vocabulary size and word-to-sound mapping between alphabetic and logographic languages.postprin

Bilingual Experience Modulates Hemispheric Lateralization in Visual Word Processing

Previous studies showed reduced hemispheric asymmetry in face perception in bilinguals compared with monolinguals, suggesting that hemispheric asymmetry in visual stimulus processing may be modulated by language reading experience. Here we examined whether this phenomenon can also be observed in bilinguals with different language backgrounds. We compared English monolinguals, European–English bilinguals (who know two alphabetic languages), and Chinese–English bilinguals (who have mastered a logographic and an alphabetic language) in an English word sequential matching task. We showed that European–English bilinguals had a stronger right visual field/left hemispheric advantage than the other two groups, suggesting that different language experiences can influence how visual words are processed in the brain. In addition, by using a computational model that implements a theory of hemispheric asymmetry in perception, we showed that this lateralization difference could be accounted for by the difference in participants’ vocabulary size and the difference in word-to-sound mapping between alphabetic and logographic languages.published_or_final_versio

How to critique consultancy reports? [5]

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An investigation into the current management of hypertension in Hong Kong: a two-phase study

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An adaptive RBF neural network model for evoked potential estimation

A method for evoked potential estimation based on an adaptive radial basis function neural network (RBFNN) model is presented in this paper. During training, the number of hidden nodes (number of RBFs) and model parameters are adjusted to fit the target signal which is obtained by averaging. In order to reduce computational complexity and the influence of noise in estimating single-trial evoked potential (EP), the number of hidden nodes is also minimized in training. After training, both peak latency and amplitude, being distinctive features of an EP, are characterized by center and height of the corresponding RBF respectively. In EP estimation, an adaptive algorithm is employed to track the peaks from trial to trial by adapting the center and height of RBFs directly. The adaptive RBFNN is tested on a computer simulated data set and clinical EP recording. Our proposed algorithm is suitable for tracking EP waveform variations.published_or_final_versio

Mediation of short and longer term effects of an intervention program to enhance resilience in immigrants from Mainland China to Hong Kong

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Tobacco Xenobiotics Release Nitric Oxide

Many xenobiotic compounds exert their actions through the release of free radicals and related oxidants [1,2], bringing about unwanted biological effects [3]. Indeed, oxidative events may play a significant role in tobacco toxicity from cigarette smoke. Here, we demonstrate the direct in vitro release of the free radical nitric oxide (•NO) from extracts and components of smokeless tobacco, including nicotine, nitrosonornicotine (NNN) and 4-(methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in phosphate buffered saline and human saliva using electron spin resonance and chemiluminescence detection. Our findings suggest that tobacco xenobiotics represent as yet unrecognized sources of •NO in the body

Assessing photochemical ozone formation in the Pearl River Delta with a photochemical trajectory model

A photochemical trajectory model (PTM), coupled with the Master Chemical Mechanism (MCM) describing the degradation of 139 volatile organic compounds (VOCs) in the troposphere, was developed and used for the first time to simulate the formation of photochemical pollutants at Wangqingsha (WQS), Guangzhou during photochemical pollution episodes between 12 and 17 November, 2007. The simulated diurnal variations and mixing ratios of ozone were in good agreement with observed data (R2=0.80, P<0.05), indicating that the photochemical trajectory model - an integration of boundary layer trajectories, precursor emissions and chemical processing - provides a reasonable description of ozone formation in the Pearl River Delta (PRD) region. Calculated photochemical ozone creation potential (POCP) indices for the region indicated that alkanes and oxygenated organic compounds had relatively low reactivity, while alkenes and aromatics presented high reactivity, as seen in other airsheds in Europe. Analysis of the emission inventory found that the sum of 60 of the 139 VOC species accounted for 92% of the total POCP-weighted emission. The 60 VOC species include C2-C6 alkenes, C6-C8 aromatics, biogenic VOCs, and so on. The results indicated that regional scale ozone formation in the PRD region can be mainly attributed to a relatively small number of VOC species, namely isoprene, ethene, m-xylene, and toluene, etc. A further investigation of the relative contribution of the main emission source categories to ozone formation suggested that mobile sources were the largest contributor to regional O3 formation (40%), followed by biogenic sources (29%), VOC product-related sources (23%), industry (6%), biomass burning (1%), and power plants (1%). The findings obtained in this study would advance our knowledge of air quality in the PRD region, and provide useful information to local government on effective control of photochemical smog in the region. © 2010 Elsevier Ltd