Human activity generates dynamic, multi-modal sensorystreams. Effectively processing this complex flow ofinformation on-the-fly is essential if one is to remember andrespond to others’ action, anticipate what they might do next,and learn how to perform new actions. Selectively attending toinformation-rich regions of activity seems key to fluentprocessing. However, what counts as information-rich likelydepends on numerous factors including relevance to the causalstructure of the activity, local opportunity for repeated viewing,and processing goals of the observer. We explored theinfluence of these factors on observers’ attention to a dynamic,novel activity sequence. A performance context elicitednuanced differences in processing in contrast to a remembercontext. Specifically, individuals given a perform contexttuned in to causally distinct regions of the action stream andfine-level event details. These findings provide altogether newinformation regarding how processing rapidly reorganizesaround novel activity and responds to the processing task athand.

Fluent event processing appears to critically involveselectively attending to information-rich junctures withincontinuously unfolding sensory streams (e.g., Newtson, 1973).What counts as information-rich would seem to depend on avariety of factors, however, including the novelty/familiarityof such events, as well as local opportunity for repeatedviewings. Using Hard, Recchia, & Tversky’s “Dwell-timeParadigm,” we investigated the extent to which viewers’attention to unfolding activity streams is affected bynovelty/familiarity and a second viewing. Viewers’ dwelltimes were recorded as they advanced twice each through threeslideshows varying in familiarity but equated on otherdimensions. Dwell time patterns revealed reorganization on anumber of fronts: a) familiarity elicited decreased dwellingoverall, b) dwell-time patterns changed systematically onsecond viewing, and c) familiarity modulated the specificnature of change associated with repeated viewing. Thesefindings illuminate reorganization in attention as actioninformation is first encountered and then quickly incorporatedto guide event processing.

From the earliest months of life, infants prefer listening to and learn better from infant-directed speech (IDS) than adult-directed speech (ADS). Yet, IDS differs within communities, across languages, and across cultures, both in form and in prevalence. This large-scale, multi-site study used the diversity of bilingual infant experiences to explore the impact of different types of linguistic experience on infants' IDS preference. As part of the multi-lab ManyBabies 1 project, we compared lab-matched samples of 333 bilingual and 385 monolingual infants' preference for North-American English IDS (cf. ManyBabies Consortium, 2020: ManyBabies 1), tested in 17 labs in 7 countries. Those infants were tested in two age groups: 6-9 months (the younger sample) and 12-15 months (the older sample). We found that bilingual and monolingual infants both preferred IDS to ADS, and did not differ in terms of the overall magnitude of this preference. However, amongst bilingual infants who were acquiring North-American English (NAE) as a native language, greater exposure to NAE was associated with a stronger IDS preference, extending the previous finding from ManyBabies 1 that monolinguals learning NAE as a native language showed a stronger preference than infants unexposed to NAE. Together, our findings indicate that IDS preference likely makes a similar contribution to monolingual and bilingual development, and that infants are exquisitely sensitive to the nature and frequency of different types of language input in their early environments.

Psychological scientists have become increasingly concerned with issues related to methodology and replicability, and infancy researchers in particular face specific challenges related to replicability: For example, high-powered studies are difficult to conduct, testing conditions vary across labs, and different labs have access to different infant populations. Addressing these concerns, we report on a large-scale, multisite study aimed at (a) assessing the overall replicability of a single theoretically important phenomenon and (b) examining methodological, cultural, and developmental moderators. We focus on infants’ preference for infant-directed speech (IDS) over adult-directed speech (ADS). Stimuli of mothers speaking to their infants and to an adult in North American English were created using seminaturalistic laboratory-based audio recordings. Infants’ relative preference for IDS and ADS was assessed across 67 laboratories in North America, Europe, Australia, and Asia using the three common methods for measuring infants’ discrimination (head-turn preference, central fixation, and eye tracking). The overall meta-analytic effect size (Cohen’s d) was 0.35, 95% confidence interval = [0.29, 0.42], which was reliably above zero but smaller than the meta-analytic mean computed from previous literature (0.67). The IDS preference was significantly stronger in older children, in those children for whom the stimuli matched their native language and dialect, and in data from labs using the head-turn preference procedure. Together, these findings replicate the IDS preference but suggest that its magnitude is modulated by development, native-language experience, and testing procedure.