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Four experiments with Chinese-English bilinguals were conducted in order to investigate the hypothesis of language nonselective access to an integrated lexicon for bilingual phonological representations. Results of a naming task (in Experiments 1 and 2) and a lexical decision task (in Experiments 3 and 4) showed homophone priming effects regardless of priming direction (English to Chinese, or Chinese to English) or English proficiency. Our findings are compatible with the BIA+ model of bilingual processing, provide further support for the hypothesis of language nonselective access to an integrated lexicon for bilingual phonological representations, and extend the hypothesis to language pairs with very different writing systems.

This paper presents an experiment that explored the role of domain–general inhibitory control on language switching. Reaction times (RTs) and event–related brain potentials (ERPs) were recorded when low–proficient bilinguals with high and low inhibitory control (IC) switched between overt picture naming in both their L1 and L2. Results showed that the language switch costs of bilinguals with high–IC were symmetrical, while that of bilinguals with low–IC were not. The N2 component failed to show a significant interaction between group, language and task, indicating that inhibition may not comes into play during the language task schema competition phase. The late positive component (LPC), however, showed larger amplitudes for L2 repeat and switch trials than for L1 trials in the high–IC group, indicating that inhibition may play a key role during the lexical response selection phase. These findings suggest that domain–general inhibitory control plays an important role in modulating language switch costs and its influence can be specified in lexical selection phase.

BackgroundHippocampal/parahippocampal structural changes accompany major depressive disorders in the elderly, but whether subthreshold depression (StD) at an advanced age is also accompanied by similar changes in hippocampal/parahippocampal volumes is still unknown. By using voxel-based morphometry (VBM) analysis of the gray matter, we explored whether there are structural alterations of the hippocampus/parahippocampus and the correlations between its volume and participants’ self-reported depressive symptoms.MethodsParticipants were 19 community-dwelling older adults with StD assessed by the Center for Epidemiologic Studies Depression scale (CES-D) scores. We collected magnetic resonance images of their brain compared to images of 17 healthy aged-matched adults. We used VBM to analyze differences in gray matter volume (GMV) of the hippocampus/parahippocampus between the two groups. Moreover, we examined the correlation between the GMV of the hippocampus/parahippocampus and participants’ self-reported depressive symptoms.ResultsVBM revealed that elderly individuals with StD had substantially reduced volumes of the right parahippocampus compared to healthy controls. Furthermore, the volumes of the hippocampus/parahippocampus were significantly associated with participants’ self-reported depressive symptoms in StD.ConclusionsGray matter volume alterations in the hippocampus/parahippocampus are correlated with subthreshold depression suggesting that early structural changes in the hippocampus/parahippocampus can constitute a risk indicator of depression.Electronic supplementary materialThe online version of this article (doi:10.1186/s12888-016-0928-0) contains supplementary material, which is available to authorized users.