Language learners track conditional probabilities to find words in continuous speech and to map words and objects across ambiguous contexts. It remains unclear, however, whether learners can leverage the structure of the linguistic input to do both tasks at the same time. To explore this question, we combined speech segmentation and cross-situational word learning into a single task. In Experiment 1, when adults ( N = 60) simultaneously segmented continuous speech and mapped the newly segmented words to objects, they demonstrated better performance than when either task was performed alone. However, when the speech stream had conflicting statistics, participants were able to correctly map words to objects, but were at chance level on speech segmentation. In Experiment 2, we used a more sensitive speech segmentation measure to find that adults ( N = 35), exposed to the same conflicting speech stream, correctly identified non-words as such, but were still unable to discriminate between words and part-words. Again, mapping was above chance. Our study suggests that learners can track multiple sources of statistical information to find and map words to objects in noisy environments. It also prompts questions on how to effectively measure the knowledge arising from these learning experiences.

Bilingualism has been hypothesized to shape cognitive abilities across the lifespan. Here, we examined the replicability of a seminal study that showed monolingual–bilingual differences in infancy (Kovács & Mehler, 2009a ) by collecting new data from 7-month-olds and 20-month-olds and reanalyzing three open datasets from 7- to 9-month-olds (D’Souza et al., 2020 ; Kalashnikova et al., 2020 , 2021 ). Infants from all studies ( N = 222) were tested in an anticipatory eye-tracking paradigm, where they learned to use a cue to anticipate a reward presented on one side of a screen during Training, and the opposite side at Test. To correctly anticipate the reward at Test, infants had to update their previously learned behavior. Across four out of five studies, a fine-grained analysis of infants’ anticipations showed that bilinguals were better able to update the previously learned response at Test, which could be related to bilinguals’ weaker initial learning during Training. However, in one study of 7-month-olds, we observed the opposite pattern: bilinguals performed better during Training, and monolinguals performed better at Test. These results show that bilingualism affects how infants process information during learning. We also highlight the potential of open science to advance our understanding of language development.