Sleep & Word Learning
Is sleep beneficial to word learning in infancy? In 2017, I will begin a 2-year study to investigate the causal and longitudinal relationship between sleep and word learning between 12- and 30-months - a period of dramatic development in both sleep and language acquisition - using actigraphy, polysomnography, sleep diary, vocabulary inventory, and automated eye-tracking.
Language-mediated Visual Attention
What is the relationship between language and cognition? While the Whorfian hypothesis (language determines cognition) remains controversial, my research shows evidence that language can mediate the way we selectively attend to information in the visual world, which begins in infancy and toddlerhood.
Bias to Relevance
In a series of eye-tracking study, toddlers saw an array of pictures and heard labels spoken in child-directed speech. Upon hearing the word Carrot, toddlers looked more at the picture of a Car, which is phonologically similar to Carrot. Toddlers also looked more at the picture of Pear, indicating their knowledge and appreciation of Pear and Carrot being related by the semantic category of food. Interestingly, biased attention to phonologically- and semantically-relevant information was stronger in toddlers with a larger vocabulary. It is possible that toddlers who know more words are, overall, cognitively more advanced and therefore able to detect relevant information faster than those with a smaller vocabulary. In reverse, it is also possible that toddlers who are able to detect relevant information faster are able to learn faster, and accumulate a larger vocabulary.
Chow, J., Davies, A. M. A., & Plunkett, K. (2017). Spoken-word recognition in 2-year-olds: The tug of war between phonological and semantic activation. Journal of Memory and Language.
What happens when we switch from one thought to another? My study on backward semantic inhibition investigates the mental processes of switching attention between different semantic categories. In the experiment, toddlers hear the following words (category in parentheses) in a sequential manner: chair (furniture), coat (clothing), table (furniture). Attending to the word Coat leads to the inhibition of the mental representations of the previous word Chair. We know that chair and the category furniture has been inhibited because toddlers' and adults' subsequent response to the word Table (another furniture) is impaired. The effect of backward semantic inhibition is observed in adults and toddlers starting from 24-months.