Presenting pictures of faces side by side is a common paradigm to assess infants' attentional biases according to social categories, such as gender, race, and language. However, seeing static faces does not represent infants' typical experience of the social world, which involves people in motion and performing actions. Here, we assessed infants'…

Object play yields enormous benefits for infant development. However, little is known about natural play at home where most object interactions occur. We conducted frame-by-frame video analyses of spontaneous activity in two 2-h home visits with 13-month-old crawling infants and 13-, 18-, and 23-month-old walking infants (N = 40; 21 boys; 75%…

A newborn arrives in this world with the inherent capacity to learn. This includes simple reflexes such as sucking, Moro reflexes, grasping etc. These "pre-installed" capacities help the baby to survive, particularly in the early months before there has been time to gaining new capabilities through learning. Once an infant starts to…

Background: Spontaneous upper extremity movements in infancy provide insight on neuromotor development. Spatiotemporal kinematics have been used to evaluate typical development of reaching, a foundational motor skill in infancy. This study evaluates the relationship between spontaneous upper extremity movements, not elicited by a toy, and motor…

It is known that the rhythms of speech are visible on the face, accurately mirroring changes in the vocal tract. These low-frequency visual temporal movements are tightly correlated with speech output, and both visual speech (e.g., mouth motion) and the acoustic speech amplitude envelope entrain neural oscillations. Low-frequency visual temporal…

The development of copying behaviours of a group of infants from 9 to 15 months of age is analysed. These behaviours are classified according to their type (mimetic or imitated) and function (instrumental, social or hybrid). The function of the behaviours is derived from observable indicators linked to dyadic interaction. Mimetic behaviours are…

Behavioural, cognitive and emotional dysregulation related to parent borderline personality disorder (BPD) may have a major impact on parent-infant interactions. We investigated the ways in which infant social withdrawal and mother sensitivity may be associated to a BPD diagnosis in mothers. Two groups of clinic-referred mother-infant dyads were…

A live video was used to study the development of visual self-recognition in a cross-sectional sample of 152 typically developing French children aged between 15 months to 6 years. Three reactions to a mark placed on the child's cheek without their knowledge were studied: the touch of the mark with their hand, the ocular responsiveness to the mark…

Emotions remain something of a mystery for most of us even when we accept their centrality to development in general and to infancy in particular. I make 2 arguments in this paper. One: that the most crucial thing about emotions is that they allow mutuality of engagement with other emotional beings--not only evoking responses, but also provoking…

Since birth, infants develop the ability to perceive a wide range of intersensory relations among various kinds of amodal temporal information. This study addresses the development of the ability to perceive duration-based intersensory relations. Three groups of infants, four, seven and 10 months old, participated in two trials of an intersensory…

Learning to walk allows infants to travel faster and farther and explore more of their environments. In turn, walking may have a cascading effect on infants' communication and subsequent responses from caregivers. We tested for an "inflection point"--a dramatic shift in the developmental progression--in infant communication and caregiver…

Purpose: Developmental functional modules (DFMs) are biological modules that are defined by their structural (morphological), functional, or developmental elements, and, in some cases, all three of these. This review article considers the hypothesis that vocal development in the first year of life can be understood in large part with respect to…

Background and Aims: The purpose of this exploratory study was to expand existing literature on prelinguistic vocalizations by reporting results of the first home-based longitudinal study examining a wide variety of behaviors and characteristics, including early vocalizations, across infants at low and elevated risk of autism spectrum disorder…

Early mother-infant coordinated interactions play a critical role in infant development. The present study describes the development of the dyadic coordination of vocalization and gaze behavior between mothers and infants over the first year of life. In addition to describing developmental trajectories of behavior, the study contributes to our…

This study used an ethological approach to explore the behavioural adaptation of nineteen infants during their first six weeks in Residential Care (RC), or a Foster Family (FF) or an Infant-Mother Centre (IMC). Direct observations were conducted once a week at bath time. Observed behaviours were: sleep-wake states, visual exploration, motor…