The role of executive control in bilingual language production: A study with Parkinson's disease individuals

Abstract

The basal ganglia are critically involved in language control (LC) processes, allowing a bilingual to utter correctly in one language without interference from the non-requested language. It has been hypothesized that the neural mechanism of LC closely resembles domain-general executive control (EC). The purpose of the present study is to investigate the integrity of bilingual LC and its overlap with domain-general EC in a clinical population such as individuals with Parkinson's disease (PD), notoriously associated with structural damage in the basal ganglia. We approach these issues in two ways. First, we employed a language switching task to investigate the integrity of LC in a group of Catalan-Spanish bilingual individuals with PD, as compared to a group of matched healthy controls. Second, to test the relationship between domain-general EC and LC we compared the performances of individuals with PD and healthy controls also in a non-linguistic switching task. We highlight that, compared to controls, individuals with PD report decreased processing speed, less accuracy and larger switching costs in terms of RT and errors in the language switching task, whereas in the non-linguistic switching task PD patients showed only increased switching cost in terms of errors. However, we report a positive correlation between the magnitudes of linguistic and non-linguistic mixing costs in individuals with PD. Taken together, these results support the notion of a critical role of the basal ganglia and connected structures in LC, and suggest a possible link between LC and domain-general EC.

On the overlap between bilingual language control and domain-general executive control

“…The current evidence indicates there is no correlation between linguistic and non-linguistic n-1 shift costs (Calabria et al, 2012;Prior & Gollan, 2013;Cattaneo et al, 2015), hereby suggesting a lack of overlap between bLC and EC, at least for those cognitive mechanisms measured through the n-1 shift cost (see also Weissberger et al, 2012). In accord with these findings, Tse & Altarriba (2014) tested a group of Cantonese-English bilingual children and revealed a lack of association between measures of language proficiency and ex-Gaussian parameters in a non-linguistic Simon switching task.…”

“…One of them is to correlate participants' behaviour in comparable tasks that either involves bLC or domain-general EC processes (e.g., Calabria, Hernández, Branzi, & Costa, 2012;Weissberger, Wierenga, Bondi, & Gollan, 2012;Prior & Gollan, 2013;Calabria, Branzi, Marne, Hernández, & Costa, 2015;Cattaneo, Calabria, Marne, Gironell, Abutalebi, & Costa 2015;Babcock & Vallesi, 2015). The argument made is that to the extent these tasks tap into comparable control processes, there should be a correlation between the effects measured in them.…”

“…In fact, some of these studies revealed that the continuous use of two languages affect the cognitive processes related to domain-general EC, such as those put at play during non-linguistic switching tasks (e.g., Prior & MacWhinney, 2010;Prior & Gollan, 2011;Prior, 2012;Wiseheart, et al, 2016), thereby suggesting a certain functional overlap between those processes involved in linguistic and non-linguistic domains of cognitive control. Despite these findings have motivated recent research to focus on the extent of this overlap (e.g., Calabria et al, 2012;Weissberger et al, 2012;Cattaneo et al, 2015;Coderre, Smith, van Heuven, & Horwitz, 2015;6 Weissberger, Gollan, Bondi, Clark, & Wierenga, 2015;De Baene, Duyck, Brass, & Carreiras, 2015), other recent findings have strongly undermined the basic assumption of the existence of an overlap between bLC and EC (e.g., Paap et al, 2013;Hernandez et al, 2013;Paap & Sawi, 2014;Duñabeitia, Hernández, Antón, Macizo, Estévez, Fuentes & Carreiras, 2014;Kousaie, Sheppard, Lemieux, Monetta, & Taler 2014;Antón, Duñabeitia, Estévez, Hernández, Castillo, Fuentes, Davidson, & Carreiras, 2014;von Bastian, Souza, Gade, 2015).…”

Exploring the role of cognitive control in syntactic processing

“…The last twenty years have seen a flourishing of studies exploring the effects of bilingualism on cognition (see Bialystok, 1988;Carlson & Meltzoff, 2008;Bialystok & Viswanathan, 2009;Kroll & Bialystok, 2013;Baum & Titone, 2014;Cattaneo, Calabria, Marne, Gironell, Abutalebi & Costa, 2015). From the resulting literature, we know that growing up with more than one language, but also, to some extent, learning a second language in adulthood, positively affects processes that are not specifically linguistic in nature, but belong to general cognition.…”

“…Critics of the bilingual advantage go as far as claiming that bilingualism does enhance inhibitory control, monitoring and switching, but that the advantage may be language-specific and not generalizable to broader cognitive processes (e.g., Paap & Greenberg, 2013); other researchers come to the more cautious conclusion that executive control in non-linguistic tasks and bilingual language control share some characteristics, but not all of them (see Calabria, Hernández, Branzi & Costa, 2012;Calabria, Branzi, Marne, Hernández & Costa, 2015;Cattaneo, Calabria, Marne, Gironell, Abutalebi & Costa, 2015).…”