Bilingual Advantage on Tasks of Interferernce Suppression and Response Inhibition Among Language Minority Youth

Children who are native Spanish-speaking Language Minority Youth (LMY) comprise the fastest growing population of students in the United States. In addition, these children lag significantly behind their non-LMY peers in academic achievement. To aid in their development of academic skills, it is necessary to evaluate individual factors that are related to later reading and math achievement. One such individual factor is executive function (EF). EF is defined as the set of cognitive skills that underlie children’s ability to regulate their thoughts and actions. Among the skills encompassed by executive function are inhibitory control (i.e., the ability to suppress a dominant response in favor of a subdominant response), working memory (i.e., the ability to maintain and manipulate information in short-term memory), and shifting (i.e., the ability to switch flexibly between tasks). Children who speak more than one language are theorized to have what is called a “bilingual advantage” in their executive function ability such that they outperform their non-LMY peers on tasks of inhibitory control. It is theorized that the bilingual advantage originates from the simultaneous activation of both languages and the constant need to select the relevant language while ignoring their other language. This conflict between languages and the need to select just one language in which to respond confers cognitive advantages that are said to generalize to inhibitory control. However, findings are mixed regarding whether the bilingual advantage exists. A closer examination of these findings suggests that the bilingual advantage is dependent upon the type of inhibitory control task administered. Specifically, the bilingual advantage is said to exist on tasks of interference suppression (IS; defined as the ability to ignore or suppress irrelevant salient perceptual information in a bivalent task and selectively attend to relevant conflicting information), but not on tasks of response inhibition (RI; defined as suppressing a dominant response in favor of a less dominant response). The goal of this study was to evaluate the different types of inhibitory control among children with some degree of exposure to both Spanish and English and to understand better whether there is a bilingual advantage conferred on tasks of interference suppression (but not on tasks of response inhibition) for children with a greater degree of bilingualism. In the current study, 100 Spanish-speaking LMY preschool students were administered an English and Spanish language measure to determine their degree of bilingualism as well as seven computerized tasks of inhibitory control. Four of the computerized tasks evaluated IS (two required verbal responses, two did not) and three of the computerized tasks evaluated RI (one required a verbal response, two did not). Consistent with the first hypothesis, the verbal and nonverbal computerized tasks measured a unitary inhibitory control construct. Consistent with the second hypothesis, results indicated that IS and RI were distinct domains within the broader construct of inhibitory control. Consistent with the third hypothesis, results indicated that a higher degree of bilingualism was associated with stronger inhibitory control, and that children’s degree of bilingualism was relatively more associated with IS than with RI. These findings support the presence of a bilingual advantage conferred to children’s inhibitory control, as well as a specific advantage conferred to inhibitory control tasks that require IS. However, degree of bilingualism was strongly related to children’s English language skills.