Summary of "Convergent cortical Representation of Semantic Processing in Bilingual"
Main argument: A shared frontal lobe system for semantic analysis of the languages and are consistent with cognitive research on bilingualism indicating that the two languages of a bilinugal person access a common semantic system.
In this paper, the authors focused on the cortical substrates of semantic processing in bilinguals using functional magnetic resonance imaging (fMRI).
Three main sources of experimental evidence support that the position that two languages of a bilingual access a commonsemantic network:
(1) sepantic comparisons between words from different languages have been shown to take no longer than comparisons between words in the same language, suggesting the integration of semantic information between languages.
(2) primed lexical decision tasks have revealed that processing of a word is faciltating about 75% as much when immediately procedes by a semantic associate in the same language.
(3) studies of interference effects or pf part-set cueing during catefory exemplar generation have shown that processing in one language can automatically interfere with processing of another, and these interference effects also tend to be about 75% of the magnitude of the corresponding with-language effects.
The conclusions of the present study are based on two complementary soures of evidence:(1) the two unilingual scans, comparing semantic and non-semantic processing in either English or Spanish, (2)and the bilingual scan, which directly contrasted semantic processing in English and Spanish.
The bilingual scan has two pontential drawbacks: (1) it yielded a null result or the absence of an effect. (2) the alternation between two languages could have led participants to use different strategies than they would use in a single-language scan, possibly encouraging them to use language-general strategies that eliminated differences that might otherwise occur.
In sum, neither the differential loss or reacquisition of languages in bilingual aphasic patients nor the apparent dissociations in cortical activation seen in whole-languages fMRI studies of bilingualism can be attributed to independent semantic subsystems.