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. 2016 Nov:40:112-127.
doi: 10.1016/j.jneuroling.2016.06.008. Epub 2016 Jul 18.

Individual differences in the bilingual brain: The role of language background and DRD2 genotype in verbal and non-verbal cognitive control

Kelly A Vaughn  1 , Aurora I Ramos Nuñez  1 , Maya R Greene  1 , Brandin A Munson  1 , Elena L Grigorenko  2 , Arturo E Hernandez  1
Affiliations

Individual differences in the bilingual brain: The role of language background and DRD2 genotype in verbal and non-verbal cognitive control

Kelly A Vaughn et al. J Neurolinguistics. 2016 Nov.

Abstract

Bilingual language control may involve cognitive control, including inhibition and switching. These types of control have been previously associated with neural activity in the inferior frontal gyrus (IFG) and the anterior cingulate cortex (ACC). In previous studies, the DRD2 gene, related to dopamine availability in the striatum, has been found to play a role in neural activity during cognitive control tasks, with carriers of the gene's A1 allele showing different patterns of activity in inferior frontal regions during cognitive control tasks than non-carriers. The current study sought to extend these findings to the domain of bilingual language control. Forty-nine Spanish-English bilinguals participated in this study by providing DNA samples through saliva, completing background questionnaires, and performing a language production task (picture-naming), a non-verbal inhibition task (Simon task), and a non-verbal switching task (shape-color task) in the fMRI scanner. The fMRI data were analyzed to determine whether variation in the genetic background or bilingual language background predicts neural activity in the IFG and ACC during these three tasks. Results indicate that genetic and language background variables predicted neural activity in the IFG during English picture naming. Variation in only the genetic background predicted neural activity in the ACC during the shape-color switching task; variation in only the language background predicted neural activity in the ACC and IFG during the Simon task. These results suggest that variation in the DRD2 gene should not be ignored when drawing conclusions about bilingual verbal and non-verbal cognitive control.

Keywords: Bilingualism; Cognitive Control; DRD2; Language Control.

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Figures

Figure 1
Figure 1. Picture Naming Task Design
A) Mixed block. Participants name pictures in English or Spanish based on the cues “diga” or “say.” B) English block. Participants name pictures in English following the cue “say.” C) Spanish block. Participants name pictures in Spanish following the cue “diga.”
Figure 2
Figure 2. Shape-Color Task Design
Participants respond to either the shape (circle/square) or color (red/blue) of the image by pressing a left or right button. When the dollar sign cues appear, participants switch sorting rules (vertical dollar sign), or repeat the same sorting rule (horizontal dollar sign). This task was completed for 5 runs, with 14 cues presented per run.
Figure 3
Figure 3. Simon Task Design
Participants press a right button for red circles and a left button for green circles. Congruent trials: red circles appearing on the right and left circles appearing on the left. Incongruent trials: red circles appearing on the left and green circles appearing on the right. Neutral trials: circles appearing in the center of the screen. Color-button associations were counterbalanced across participants.
Figure 4
Figure 4
Distribution of English and Spanish Proficiency Scores
Figure 5
Figure 5. Relationship Between Age of English Acquisition and English and Spanish Proficiency
This graph shows the relationship between the age at which these Spanish-English bilinguals began learning English and their achieved proficiency in both English and Spanish. Bilinguals who began learning English earlier in life achieved a proficiency in English that exceeded their Spanish proficiency. After about the age of seven, learning English no longer appears to be detrimental to learning Spanish. Bilinguals maintained a higher Spanish than English proficiency when English was introduced later in life.
Figure 6
Figure 6. IFG activity relationships during English Picture Naming
Red/yellow = positive relationship. Blue = negative relationship A) Left IFG relationship with A1 carrier status (carriers > non-carriers) controlling for AOA, English proficiency, and Spanish proficiency B) Left IFG relationship with AOA controlling for A1 carrier status, English proficiency, and Spanish proficiency C) Right IFG relationship with A1 carrier status (carriers > non-carriers) controlling for AOA, English proficiency, and Spanish proficiency
Figure 7
Figure 7. Histogram of t-statistics for differences in neural activity in the IFG and ACC for the contrast “switch cues – repeat cues” during the shape-color task
All participants showed more activity for switch cues compared to repeat cues in the regions of interest.
Figure 8
Figure 8. ACC activity relationship during shape-color task
Relationship to A1 carrier status (carriers > non-carriers) for Switch - Repeat conditions Red/yellow = positive relationship. Blue = negative relationship
Figure 9
Figure 9. Histogram of t-statistics for differences in neural activity in the IFG and ACC for the contrast “incongruent trials – congruent trials” during the Simon task
All participants showed more activity for incongruent trials compared to congruent trials in the regions of interest.
Figure 10
Figure 10. ACC activity relationships during Simon task (Incongruent - Congruent conditions)
Red/yellow = positive relationship. Blue = negative relationship A) Relationship with AOA controlling for A1 carrier status, English proficiency, and Spanish proficiency B) Relationship with English proficiency controlling for A1 carrier status, AOA, and Spanish proficiency C) Relationship with Spanish proficiency controlling for A1 carrier status, AOA, and English proficiency
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References

    1. Abutalebi J, Della Rosa PA, Ding G, Weekes B, Costa A, Green DW. Language proficiency modulates the engagement of cognitive control areas in multilinguals. Cortex. 2013;49(3):905–911. doi: 10.1016/j.cortex.2012.08.018. - DOI - PubMed
    1. Abutalebi J, Della Rosa PA, Green DW, Hernandez M, Scifo P, Keim R, Costa A. Bilingualism tunes the anterior cingulate cortex for conflict monitoring. Cerebral Cortex. 2012;22(9):2076–2086. doi: 10.1093/cercor/bhr287. - DOI - PubMed
    1. Bialystok E, Craik FI, Klein R, Viswanathan M. Bilingualism, aging, and cognitive control: evidence from the Simon task. Psychology and Aging. 2004;19(2):290–303. doi: 10.1037/0882-7974.19.2.290. - DOI - PubMed
    1. Bialystok E, Craik FIM, Green DW, Gollan TH. Bilingual Minds. Psychological Science in the Public Interest. 2009;10(3):89–129. doi: 10.1177/1529100610387084. - DOI - PubMed
    1. Cox RW. AFNI: Software for Analysis and Visualization of Functional Magnetic Resonance Neuroimages. Computers and Biomedical Research. 1996;29(3):162–173. http://dx.doi.org/10.1006/cbmr.1996.0014. - DOI - PubMed

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