Noriaki Yusa

Distinct Roles of Left Inferior Frontal Regions that Explain Individual Differences in Second Language Acquisition

Second language (L2) acquisition is more susceptible to environmental and idiosyncratic factors than first language acquisition. Here, we used functional magnetic resonance imaging for L2 learners of different ages of first exposure (mean: 12.6 and 5.6 years) in a formal school environment, and compared the cortical activations involved in processing English sentences containing either syntactic or spelling errors, where the testing ages and task performances of both groups were matched. We found novel activation patterns in two regions of the left inferior frontal gyrus (IFG) that correlated differentially with the performances of the late and early learners. Specifically, activations of the dorsal and ventral triangular part (F3t) of the left IFG correlated positively with the accuracy of the syntactic task for the late learners, whereas activations of the left ventral F3t correlated negatively with the accuracy for the early learners. In contrast, other cortical regions exhibited differential correlation patterns with the reaction times (RTs) of the syntactic task. Namely, activations of the orbital part (F3O) of the left IFG, as well as those of the left angular gyrus, correlated positively with the RTs for the late learners, whereas those activations correlated negatively with the RTs for the early learners. Moreover, the task‐selective activation of the left F3O was maintained for both the late and early learners. These results explain individual differences in L2 acquisition, such that the acquisition of linguistic knowledge in L2 is subserved by at least two distinct inferior frontal regions of the left F3t and F3O. Hum Brain Mapp, 2009.

Left middle temporal deactivation caused by insufficient second language word comprehension by Chinese–Japanese bilinguals

Neuroimaging studies of second language (L2) comprehension have reported that the low L2 proficiency of non-proficient learners is associated with greater brain activation in several regions due to the increased deployment of resources to process a not-so-familiar language. However, until now, no attention has been paid to the possibility that the non-proficiency of such learners can actually lead to insufficient use of brain regions where the first language (L1) speakers show increased brain activation. Here, our fMRI study found that the left middle temporal gyrus was less active during the L2 lexical decision of non-proficient Chinese learners of Japanese as L2 than during the L1 lexical decision of native Japanese speakers. Our results indicate that the difficulty experienced by non-proficient L2 learners in L2 lexical decision is due to their less active use of the left middle temporal gyrus, which is, contrastively, used actively by L1 speakers in their L1 lexical decision. These results in turn suggest that left middle temporal activation reflects whether or not the lexical information of L2 words is formed appropriately as part of the L2 mental lexicon.

Explicit Article Instruction in Definiteness, Specificity, Genericity and Perception

In our study, we focused on the nominal domain, as it is an area of persistent difficulty for Japanese learners of English. We administered pretests, instruction, and posttests to 14 participants. The instruction part covered three weeks of a 15-week semester. The participants were randomly divided into two groups: one instruction group (n = 7) and one control group (n = 7). The control group did not receive any instruction. The posttest was given at the end of the instruction period to both groups and again at the end of the semester. The instruction group received instruction about the properties of definiteness, specificity, and genericity. Learners were also given instruction on the perception of articles in spoken English. The results of our study show that despite the complexity of articles, learners did have a better understanding of specificity and their perception of the indefinite article in oral input improved. We discuss the implications of generative SLA research applied to the language classroom.

The long-term effect of explicit instruction on learners’ knowledge on English articles:

This study examines the role of explicit instruction in article semantics to L2 learners of English. Two types of generic sentences, expressed by different articles, were tested over time. An instruction group (n = 21), a control group (n = 16) and a native English speaker control group (n = 9) participated in the study. The instruction group received nine 60-minute lessons across 9 weeks. A pre-test was administered to both groups before instruction began and four post-tests were given to both groups. The results from delayed post-tests show that the instruction group improved, but after one year little knowledge was retained. The findings suggest that explicit knowledge of articles is unlikely to be retained unless ongoing instruction is achieved.

Social Interaction Affects Neural Outcomes of Sign Language Learning As a Foreign Language in Adults

Children naturally acquire a language in social contexts where they interact with their caregivers. Indeed, research shows that social interaction facilitates lexical and phonological development at the early stages of child language acquisition. It is not clear, however, whether the relationship between social interaction and learning applies to adult second language acquisition of syntactic rules. Does learning second language syntactic rules through social interactions with a native speaker or without such interactions impact behavior and the brain? The current study aims to answer this question. Adult Japanese participants learned a new foreign language, Japanese sign language (JSL), either through a native deaf signer or via DVDs. Neural correlates of acquiring new linguistic knowledge were investigated using functional magnetic resonance imaging (fMRI). The participants in each group were indistinguishable in terms of their behavioral data after the instruction. The fMRI data, however, revealed significant differences in the neural activities between two groups. Significant activations in the left inferior frontal gyrus (IFG) were found for the participants who learned JSL through interactions with the native signer. In contrast, no cortical activation change in the left IFG was found for the group who experienced the same visual input for the same duration via the DVD presentation. Given that the left IFG is involved in the syntactic processing of language, spoken or signed, learning through social interactions resulted in an fMRI signature typical of native speakers: activation of the left IFG. Thus, broadly speaking, availability of communicative interaction is necessary for second language acquisition and this results in observed changes in the brain.

A longitudinal fMRI study of neural plasticity in the second language lexical processing

P2-h26 Neural mechanisms of the lexically ambiguity resolution—An MEG study Aya Ihara1, Tomoe Hayakawa1,2, Qiang Wei1,3, Shinji Munetsuna1,3, Norio Fujimaki1,3 1 Biological ICT Group, National Institute of Information and Communications Technology, Kobe, Japan; 2 Department of Psychology, Teikyo University, Tokyo, Japan; 3 Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, Kitakyushu, Japan