Event Abstract

An fMRI study of executive control during translation and oral reading in Cantonese-English bilingual speakers

  • 1 University of Hong Kong, Hong Kong, SAR China
  • 2 University of Melbourne, Australia

Neuroimaging techniques are used to test the neural basis of spoken language in bilingual speakers (Abutalebi et al. 2012; Della-Rosa et al., 2013). The neural basis of written language (bi-scriptal bilinguals) is less well studied (though see Chee and colleagues). Previous studies on the neural bases of language processing have small samples and the scripts are typically from the same language family i.e. Spanish-English, German-English bilinguals (Luk, Green, Abutalebi, & Grady, 2012; Meschyan & Hernandez, 2006). Chinese and English languages use different scripts from two language families. Neural studies of oral reading in bi-scriptal bilinguals who speak two different languages and use two different writing systems are of value (Dijkstra, 2005). We know translation of written words requires inhibition of irrelevant orthographic input to derive a target (Price, Green, & Von Studnitz, 1999). Assuming competition arises in oral reading for spoken output, executive control may be required to resolve competition by inhibiting irrelevant (L1) schema. It might be expected that oral reading will generate similar activation in regions for executive control when compared to translation. Furthermore, since forward translation requires inhibition of (more proficient) L1, more activation in these areas might be observed for bi-scriptals. Study aims and hypotheses Greater inhibition is assumed for the non-target dominant language in reading and translation tasks. It is therefore predicted that L2 reading and translation will show more brain activation than L1 reading and L1 translation in regions involved in executive control such as anterior cingulate gyrus (ACC), dorsolateral prefrontal cortex (DLPFC), inferior frontal gyrus (IFG), supplementary motor area (SMA), caudate nucleus and sub-thalamic nucleus, putamen and the supramarginal gyrus. Furthermore, is expected that translation will show similar activation to oral reading of the same stimuli. Method 19 Cantonese-English bilinguals (9 males, 10 females) were recruited. All participants reported dominance in L1 (Cantonese) and acquisition of L2 (English) before the age of 10 years. Mean age was 21.95 years (SD=1.78) ranging between 20 and 26 years. Language background data was collected via questionnaire. Self-rating of L1 and L2 proficiency regarding comprehension, speaking, reading and writing was also taken. A scale of 1 to 10 was used with 10 as highest proficiency. The average score of proficiency in L1 was 9.01 (SD = 0.97) and L2 proficiency was 8.29 (SD = 0.68). All participants were matched for L2 proficiency and right-handed. The Human Research Ethics Committee of the University of Hong Kong approved the protocol. MR scanning The fMRI experiment was carried out with a 3-T Trio MRI scanner housed in the Department of Diagnostic Radiology, University of Hong Kong. Sixty written stimuli from the high and middle frequency ranges in L1 and L2 were prepared. Conceptual translation equivalents were excluded. The translation task was administered prior to reading. Participants were instructed to restrict movement during data collection and they were informed when the upcoming task (oral reading or word translation) was forthcoming. During the experiment, stimuli in the reading and translation tasks were presented for 750ms and 960ms respectively. In between each stimulus, a “+” sign appeared and jittered on screen for 1617ms, 3011ms or 4613ms to minimize rhythmic activation. This procedure was repeated twice. Results There was no significant difference between reading in L1 and L2 t(18)=0.63, p=0.35. Backward translation was significantly more accurate than forward translation t(18) = 4.84, p<.001. Therefore, forward translation is more difficult. When translation and oral reading were contrasted, greater activation was found for translation in predicted brain areas of executive control e.g. caudate nucleus for both L1 and L2 with L1 input and L2 input. When L1 reading and translation were contrasted, there was more activation in left precuneus, left medial frontal gyrus and right anterior cingulum. There are no significant differences in the L2 reading versus L2 translation contrast. Conclusions Forward translation involves greater activation in executive control brain areas (SMA, putamen and the middle frontal gyrus) than backward translation and there was evidence of greater activation in the caudate nucleus for translation compared to reading. The results are in line with predictions of models in the field of bilingual reading (Dijkstra, 2005) and translation (Kroll & Stewart, 1994) as well as the Inhibitory Control model of bilingual language production (Abutalebi & Green, 2008). The IC model assumes that language task schemas are used to control motor output in a bilingual lexico-semantic system. Competition between L1 and L2 word schemas occurs during spoken word production. To achieve spoken word production in the target language, non-target language schemas must be inhibited and the target language schema activated. The IC model assumes that the amount of inhibition depends on the relative proficiency in two languages and specifically that greater inhibition is required to suppress the most dominant language. Inhibition of L1 task schema will be stronger compared to L2, if L2 proficiency is reduced. Our results revealed greater activation in caudate nucleus, a brain area related to executive control, in translation compared to reading when language type was controlled. Indeed, regions of the IC cognitive control network were found in nearly all contrasts. This is consistent with the IC model. Assuming that schema competition occurs in language production and is non-selective, executive control seems to be used to inhibit irrelevant response schemas to resolve any competition. Both reading and translation, therefore, involve executive control to resolve the competition for response during production on translation tasks. Written translation probably requires inhibition of non-target orthographic input while searching for a translation equivalent (Price, Green, & Von Studnitz, 1999). In the case of Chinese, multiple pronunciations are possible because characters not only afford many different possible pronunciations (Weekes et al. 2008), they have several possible meanings due to semantic radicals (Weekes et al. 1997). Brain activity was greater in translation than reading showing greater recruitment of neural reserve for translation. However for Chinese (L1), activation in DLFPC was greater for reading. We contend that inhibitory control is engaged for oral reading in L1 and L2 and extend the IC model to explain bilingual oral reading in Chinese-English (see Figure 1).

Figure 1

References

Abutalebi, J., & Green, D. W. (2008). Control mechanisms in bilingual language production: Neural evidence from language switching studies. Language and Cognitive Processes, 23(4), 557-582.

Abutalebi, J., Della Rosa, P.A., Ding, G.S., Weekes, B.S., Costa, A., & Green, D.W. (2012). Language proficiency modulates the engagement of cognitive control areas in multilinguals. Cortex. doi: 10.1016/j.cortex.2012.08.018.

Chee, M.W.L., Caplan, D., Soon, C.S., Sriram, N., Tan, E.W.L., Thiel, T., & Weekes, B.S. (1999). Processing of visually presented sentences in Mandarin and English studied with fMRI. Neuron, 23(1), 127-137.

Chee, M.W.L., Weekes, B.S., Lee, K.M., Soon, C.S., Schreiber, A., Hoon, J.J., & Chee, M. (2000). Overlap and dissociation of semantic processing of Chinese characters, English words, and pictures: Evidence from fMRI. NeuroImage, 12, 392-403.

Della Rosa, P.A., Videsott, G., Borsa, V.M., Canini, M., Weekes, B.S., Franceschini, R., & Abutalebi, J. (2013). A neural interactive location for multilingual talent. Cortex. doi: 10.1016/j.cortex.2012.12.001

Dijkstra, T. (2005). Bilingual visual word recognition and lexical access. Handbook of bilingualism: Psycholinguistic approaches, 179-201.

Kroll, J. F., & Stewart, E. (1994). Category interference in translation and picture naming: Evidence for asymmetric connections between bilingual memory representations. Journal of Memory and Language, 33(2), 149-174.

Luk, G., Green, D. W., Abutalebi, J., & Grady, C. (2012). Cognitive control for language switching in bilinguals: A quantitative meta-analysis of functional neuroimaging studies. Language and Cognitive Processes, 27(10), 1479-1488.

Meschyan, G., & Hernandez, A. E. (2006). Impact of language proficiency and orthographic transparency on bilingual word reading: An fMRI investigation. NeuroImage, 29(4), 1135-1140.

Price, C. J., Green, D. W., & Von Studnitz, R. (1999). A functional imaging study of translation and language switching. Brain, 122(12), 2221-2235.

Weekes, B.S., Chen, M.J., & Yin, W-G. (1997). Anomia without dyslexia in Chinese. Neurocase, 3, 51-60.

Weekes, B.S., Chan, A.H., & Tan, L.H. (2008). Effects of age of acquisition on brain activation during Chinese character recognition. Neuropsychologia, 46(7), 2086-2090.

Keywords: reading, translation, proficiency level, Chinese, executive control

Conference: Academy of Aphasia 55th Annual Meeting , Baltimore, United States, 5 Nov - 7 Nov, 2017.

Presentation Type: poster or oral

Topic: Consider for student award

Citation: Ramanujan K, Kong M and Weekes BS (2019). An fMRI study of executive control during translation and oral reading in Cantonese-English bilingual speakers. Conference Abstract: Academy of Aphasia 55th Annual Meeting . doi: 10.3389/conf.fnhum.2017.223.00040

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Received: 02 May 2017; Published Online: 25 Jan 2019.

* Correspondence: Prof. Brendan S Weekes, University of Hong Kong, Hong Kong, Hong Kong, SAR China, 481709@frontiersin.org