Infants' preference for vowelharmony (VH, a phonotactic constraint that requires vowels in a word to be featurally similar) is thought to be language-specific: Monolingual infants learning VH languages show a listening preference for VH patterns by 6 months of age, while those learning non-VH languages do not (Gonzalez-Gomez et al., 2019; Van…

Words influence cognition well before infants know their meanings. For example, three-month-olds are more likely to form visually based categories when exemplars are paired with spoken words than with sine-wave tones, a likely precursor to learning symbolic relations between words and their referents. However, it is unclear why words have these…

Recent research has demonstrated that individual differences in infant attention to faces and voices of women speaking predict language outcomes in childhood. These findings have been generated using two new audiovisual attention assessments appropriate for infants and young children, the Multisensory Attention Assessment Protocol (MAAP) and the…

This study explores how 7-month-old infants categorize graphical images varying in basic perceptual features by using a fast periodic visual stimulation (FPVS) task. Most participants were Caucasian and their parents had a higher education, but the family's socioeconomic background was mixed. Experiment 1 (N = 23) tested brain responses to…

Infants can help and share in the second year of life. However, there is limited knowledge as to variability in these behaviors as a function of target (e.g., caregiver vs. unfamiliar adult) and the influence of caregiver support on infant prosocial behavior. Infants (N = 268, 124 female) at 1-2 years of age (M = 1.47, SD = 0.27) and again at 2-3…

As they develop into mature speakers of their native language, infants must not only learn words but also the sounds that make up those words. To do so, they must strike a balance between accepting speaker-dependent variation (e.g., mood, voice, accent) but appropriately rejecting variation when it (potentially) changes a word's meaning (e.g., cat…

In direct interactions with others, 9-month-old infants' learning about objects is facilitated when the interaction partner addresses the infant through eye contact before looking toward an object. In this study we investigated whether similar factors promote infants' observational learning from third-party interactions. In Experiment 1,…

This research examined how 5-, 8-, and 11-month-olds with female primary caregivers mentally represented faces using a familiarization procedure similar to real-world experience in which infants have greater exposure to female faces aged 21-39 years than other face types. We predicted infants would form weighted representations of faces (i.e.,…

Learning always happens from input that contains multiple structures and multiple sources of variability. Though infants possess learning mechanisms to locate structure in the world, lab-based experiments have rarely probed how infants contend with input that contains many different structures and cues. Two experiments explored infants' use of two…

Parents commonly vocalize to infants to mitigate their distress, especially when holding them is not possible. Here we examined the relative efficacy of parents' speech and singing (familiar and unfamiliar songs) in alleviating the distress of 8- and 10-month-old infants (n = 68 per age group). Parent-infant dyads participated in 3 trials of the…

Accurate perception of emotional (facial) expressions is an essential social skill. It is currently debated whether emotion categorization in infancy emerges in a "broad-to-narrow" pattern and the degree to which language influences this process. We used an habituation paradigm to explore (a) whether 14- and 18-month-old infants perceive…

Over the past decade, numerous studies have reported that infants prefer prosocial agents (those who provide help, comfort, or fairness in distributive actions) to antisocial agents (those who harm others or distribute goods unfairly). We meta-analyzed the results of published and unpublished studies on infants aged 4-32 months and estimated that…

Previous event-related potential (ERP) work has indicated that the neural processing of action sequences develops with age. Although adults and 9-month-olds use a semantic processing system, perceiving actions activates attentional processes in 7-month-olds. However, presenting a sequence of action context, action execution and action conclusion…

This research examined whether infants tested longitudinally at 10, 14, and 16 months of age (N = 58) showed evidence of perceptual narrowing based on face gender (better discrimination of female than male faces) and whether changes in caregiving experience longitudinally predicted changes in infants' discrimination of male faces. To test face…

The present research investigated the role of familiarity and proximity in infants' comprehension of displaced speech. When 13-and 16-month-old infants heard a researcher talk about a familiar person immediately after she left the room, they showed comprehension of the name by looking, pointing, or searching for the person in question. The…