Bilinguals have been shown to outperform monolinguals on inhibitory control tasks that measure suppression of irrelevant information. However, no mechanism is established for development of this advantage. Since bilinguals activate their languages in parallel during comprehension, they may face higher processing demands. As a result, they may recruit more cognitive resources for processing, leading to changes in inhibitory mechanisms. In the present dissertation, three experiments aimed to identify a mechanism through which bilingual language processing influences inhibitory control. In Experiment 1, monolinguals and bilinguals listened to native-language words and identified them from among four pictures while their eye-movements were tracked. Target pictures (e.g., hamper) appeared together with similar-sounding competitor pictures (e.g., hammer) and two neutral pictures. Following each eye-tracking trial, priming trials indexed residual activation of preceding target and filler words, and residual inhibition of preceding competitor words. Eye-tracking findings showed similar magnitudes of competitor activation across monolinguals and bilinguals; priming probe findings showed more competitor inhibition in monolinguals than in bilinguals. In Experiment 2, monolinguals' and bilinguals' competitor inhibition during comprehension was compared to performance on a linguistic Stroop inhibition task and two nonlinguistic Stroop and Simon inhibition tasks, as well as to letter and category fluency tasks. Bilinguals showed an accuracy advantage over monolinguals on the nonlinguistic Stroop task, and recruited the nonlinguistic Stroop inhibition mechanism during language comprehension. Moreover, in bilinguals, category and letter fluency scores suggested increased recruitment of cognitive control to retrieve weaker linguistic representations. In Experiment 3, bimodal and unimodal Stroop tasks were developed to match processing components of the auditory-visual word comprehension task. Bilinguals showed a reaction time advantage on the bimodal Stroop task. Moreover, while monolinguals' inhibition performance during word comprehension correlated with bimodal Stroop inhibition, bilinguals' inhibition performance during word comprehension correlated with unimodal Stroop inhibition. These findings confirm modality-general influences on inhibition in bilinguals, but not monolinguals. Together, Experiments 1-3 identified different inhibition mechanisms in monolinguals' and bilinguals' auditory comprehension, and suggested that a central inhibitory mechanism may be shaped by bilingual experience. Future work is discussed, including behavioral and neuroimaging approaches, to study the language-cognition intersection across the lifespan.

Last modified

• 09/10/2018

Creator

• Katina Henrike Blumenfield

DOI

• https://doi.org/10.21985/N2915J

Subject

• Communication Sciences and Disorders - Speech and Language Pathology

Keyword

• Eye-Tracking
• Stroop Task
• Bilingualism
• Negative Priming
• Comprehension
• Inhibition

Date created

• 2008-05-12

Resource type

• Dissertation

Rights statement

• In Copyright