Recent theories claim that prediction supports language development, and previous findings are in line with this view (Dell & Chang, 2014; Reuter et al., under revision). However, because behavioral measures of prediction are indirect, it’s unclear what representations are activated during processing, and how specific those representations are (Rabagliati et al., 2016). Is predicting a word like cookie via semantically related words like eat, yum, and mouth distinct from comprehending the word cookie itself? We used an eye-tracking paradigm to evaluate how infants processed different types of sentences (neutral, prediction, and repetition). Findings indicate that infants predict and comprehend words, replicating prior results (Reuter et al., under revision). Findings further suggest that infants can activate and pre-activate (predict) specific lexical representations during language processing: The behavioral dynamics of prediction are distinct from those of repeated comprehension. In sum, these findings further suggest that prediction supports both language processing and language development in infancy.
We thank all participant families. We also thank Chandra Greenberg and Claire Robertson for their assistance with stimuli and data collection, and Princeton Baby Lab research assistants for their help recruiting and scheduling participants.