HOW BILINGUALS' COMPREHENSION OF CODE-SWITCHES INFLUENCES ATTENTION AND MEMORY

Abstract

Bilinguals sometimes code-switch between their shared languages. While psycholinguistics research has focused on the challenges of comprehending code-switches compared to single-language utterances, bilinguals seem unhindered by code-switching in communication, suggesting benefits that offset the costs. I hypothesize that bilinguals orient their attention to speech content after hearing a code-switch because they draw a pragmatic inference about its meaning. This hypothesis is based on the pragmatic meaningfulness of code-switches, which speakers may use to emphasize information, signal their identity, or ease production difficulties, inter alia. By considering how code-switches may benefit listeners, this research attempts to better align our psycholinguistic understanding of code-switch processing with actual bilingual language use, while also inspiring future work to investigate how diverse language contexts may facilitate learning in educational settings.

In this dissertation, I share the results of three pre-registered experiments with Spanish-English bilinguals that evaluate how hearing a code-switch affects attention and memory. Experiment 1a shows that code-switches increase bilinguals’ self-reported attention to speech content and improve memory for that information, compared to single-language equivalents. Experiment 1b demonstrates that this effect requires bilingual experience, as English-speaking monolinguals did not demonstrate increased attention upon hearing a code-switch.

Experiment 2 attempts to replicate these results and establish the time course of the attentional effect using an EEG measure previously associated with attentional engagement (alpha power). However, I conclude that alpha power was not a valid measure of attention to speech content in this experiment.

In Experiment 3, bilinguals again showed better memory for information heard in a code-switched context, with a larger benefit for those with more code-switching experience and when listeners believed the code-switches were natural (as opposed to inserted randomly, removing the element of speaker choice). This suggests that the memory benefit comes from drawing a pragmatic inference, which likely requires prior code-switching experience and a belief in code-switches’ communicative purpose.

These experiments establish that bilingual listeners derive attentional and memory benefits from ecologically valid code-switches—challenging a simplistic interpretation of the traditional finding of “costs.” Further, these findings motivate future applied work assessing if/how code-switches might benefit learning in educational contexts.