English-learning infants attend to lexical stress when learning new words. Attention to lexical stress might be beneficial for word learning by providing an indication of the grammatical class of that word. English disyllabic nouns commonly have trochaic (strong-weak) stress, whereas English disyllabic verbs commonly have iambic (weak-strong)…

Infants' representations of physical events are surprisingly flexible. Brief exposure to one event can immediately enhance infants' representations of another event. The present experiments tested two potential mechanisms underlying this priming: enhanced encoding or improved retrieval. Five-month-olds saw a target block become hidden inside a…

Correct counting respects the stable order principle whereby the count terms are recited in a fixed order every time. The 4 experiments reported here tested whether precounting infants recognize and prefer correct stable-ordered counting. The authors introduced a novel preference paradigm in which infants could freely press two buttons to activate…

Recently it has been proposed that sensitivity to nonarbitrary relationships between speech sounds and objects potentially bootstraps lexical acquisition. However, it is currently unclear whether preverbal infants (e.g., before 6 months of age) with different linguistic profiles are sensitive to such nonarbitrary relationships. Here, the authors…

Mutual exclusivity (ME) refers to the assumption that there are one-to-one relations between linguistic forms and their meanings. It is used as a word-learning strategy whereby children tend to map novel labels to unfamiliar rather than familiar referents. Previous research has indicated a relation between ME and vocabulary development, which…

The present study investigated infants' knowledge about familiar nouns. Infants (n = 46, 12-20-month-olds) saw two-image displays of familiar objects, or one familiar and one novel object. Infants heard either a matching word (e.g. "foot' when seeing foot and juice), a related word (e.g. "sock" when seeing foot and juice) or a nonce…

In human children and adults, familiar face types--typically own-age and own-species faces--are discriminated better than other face types; however, human infants do not appear to exhibit an own-age bias but instead better discriminate adult faces, which they see more often. There are two possible explanations for this pattern: Perceptual…

The development of theory of mind (ToM) in infancy has been mainly documented through studies conducted on a single age group with a single task. Very few studies have examined ToM abilities other than false belief, and very few studies have used a within-subjects design. During 2 testing sessions, infants aged 14 and 18 months old were…

Recent work has demonstrated that the addition of multiple talkers during habituation improves 14-month-olds' performance in the switch task (Rost & McMurray, 2009). While the authors suggest that this boost in performance is due to the increase in acoustic variability (Rost & McMurray, 2010), it is also possible that there is…

We apply a biopsychosocial conceptualization to attention development in the 1st year and examine the role of neurophysiological and social processes on the development of early attention processes. We tested whether maternal behavior measured during 2 mother-child interaction tasks when infants (N = 388) were 5 months predicted infant medial…

This study aimed to investigate specific associations between structural and acoustic characteristics of infant-directed (ID) speech and word recognition. Thirty Italian-acquiring children and their mothers were tested when the children were 1;3. Children's word recognition was measured with the looking-while-listening task. Maternal ID speech was…

The present study investigates English-learning infants' early understanding of the link between the grammatical category "verb" and the conceptual category "event," and their ability to recruit morphosyntactic information online to learn novel verb meanings. We report two experiments using an infant-controlled…

Early selective attention skills are a crucial building block for cognitive development, as attention orienting serves as a primary means by which infants interact with and learn from the environment. Although several studies have examined infants' attention orienting using the spatial cueing task, relatively few studies have examined…

Early in life, infants possess an effective face-processing system which becomes specialized according to the faces present in the environment. Infants are also exposed to the voices and sounds of caregivers. Previous studies have found that face-voice associations become progressively more tuned to the types of association most prevalent in the…

Children (aged 6-10) and adults (total N = 136) completed a novel visual perspective-taking task that allowed quantitative comparisons across age groups. All age groups found it harder to judge the other person's perspective when it differed from their own. This egocentric interference did not decrease with age, even though, overall, performance…