Ana Maria Gonzalez-Barrero & Aparna Nadig (School of Communication Sciences and Disorders, McGill University; Centre for Research on Brain, Language and Music)
ana.gonzalez@mail.mcgill.ca
Bilingualism; Autism Spectrum Disorders; Executive Functioning; Set-shifting skills; English-French-Spanish
While many studies have examined the impact of bilingualism on Executive Functions (EF) in typically-developing children, few have investigated a neurodevelopmental disorder with known EF impairments. If a bilingual advantage exists (Bialystok & Martin, 2004; Bialystok & Viswanathan, 2009), it might mitigate executive dysfunction in such a case. Children with Autism Spectrum Disorders (ASD) demonstrate EF impairments, specifically, they tend to exhibit perseverative responses on set-shifting tasks (e.g., Ozonoff et al., 2004). Conversely, they are not impaired in short-term memory (e.g., Boucher et al., 2012; Zinke et al., 2010). We examine the impact of bilingualism on EF in ASD with a special interest in set-shifting abilities. We hypothesized that bilingual children with ASD would be impaired in set-shifting relative to bilingual typically-developing (TYP) children, but would be less impaired than monolinguals with ASD (biTYP> biASD> monoASD). As a control we hypothesized that short-term memory would not differ between groups.
Bilingual TYP, bilingual ASD, and monolingual ASD groups were matched pairwise on nonverbal IQ and age. The target sample includes 20 biTYP, 15 biASD, and 15 monoASD 5- to 9-year-olds. Participants include French, Spanish or English speakers (or speakers of any 2 of these languages). We examined EF via parental report on the Behavior Rating Inventory of Executive Functioning (BRIEF; Gioia et al., 1996). To evaluate set-shifting we used a computerized version of the Dimensional Change Card Sort task (DCCS; Zelazo, 2006). Short-term memory was assessed by the number repetition subtest of the Clinical Evaluation of Language Fundamentals (CELF-4; Semel et al., 2003).
Preliminary data is available from 7 biTYP, 7 biASD, and 7 monoASD children. Findings generally pattern in line with our predictions. There was a significant difference between groups for the General Executive Composite Score of the BRIEF (lower scores = higher functioning: biTYP M = 46; biASD M = 58; monoASD M = 65; p = .008). Post-hoc tests revealed that the Bilingual TYP and Monolingual ASD groups were significantly different (p = .007), whereas the Monolingual and Bilingual ASD groups (p = .56) and Bilingual TYP and Bilingual ASD groups (p = .12) were not. The same pattern was found for the shifting sub-scale.
On the DCCS task a “pass” is correctly answering 5 of 6 post-switch trials. The percentage of children passing the post-switch phase was: biTYP= 100%; biASD= 86%; monoASD = 57%. This difference did not reach significance (p= .08), nor did a measure of switch cost on response time. Finally, short-term memory was not significantly different across groups.
Data collection is ongoing and will allow us to investigate in a larger sample if executive function difficulties, particularly in set-shifting ability, experienced by monolinguals with ASD are significantly reduced in bilinguals with ASD.
References
[1] Bialystok, E., & Martin, M. M. Attention and inhibition in bilingual children: Evidence from the dimensional change card sort task. Developmental Science, 7:325-339, 2004.
[2] Bialystok, E., & Viswanathan, M. Components of executive control with advantages for bilingual children in two cultures. Cognition, 112:494-500, 2009.
[3] Boucher, J., Mayes, A., & Bigham, S. (2012). Memory in autistic spectrum disorder. Psychological Bulletin, 138:458-496, 2012.
[4] Ozonoff, S., Cook, I., Coon, H., Dawson, G., Joseph, R. M., Klin, A., … & Wrathall, D. (2004). Performance on Cambridge Neuropsychological Test Automated Battery subtests sensitive to frontal lobe function in people with autistic disorder: evidence from the Collaborative Programs of Excellence in Autism network. Journal of Autism and Developmental Disorders, 34:139-150, 2004.
[5] Zelazo, P. D. The Dimensional Change Card Sort (DCCS): A method of assessing executive function in children. Nature Protocols, 1:297-301, 2006.
[6] Zinke, K., Fries, E., Altgassen, M., Kirschbaum, C., Dettenborn, L., & Kliegel, M. Visuospatial short-term memory explains deficits in tower task planning in high-functioning children with autism spectrum disorder. Child Neuropsychology, 16:229-241, 2010.