Computational approaches to understanding interaction and development.

Audio-visual recording and location tracking produce enormous quantities of digital data with which researchers can document children's everyday interactions in naturalistic settings and assessment contexts. Machine learning and other computational approaches can produce replicable, automated measurements of these big behavioral data. The economies of scale afforded by repeated automated measurements offer a potent approach to investigating linkages between real-time behavior and developmental change. In our work, automated measurement of audio from child-worn recorders-which quantify the frequency of child and adult speech and index its phonemic complexity-are paired with ultrawide radio tracking of children's location and interpersonal orientation. Applications of objective measurement indicate the influence of adult behavior in both expert ratings of attachment behavior and ratings of autism severity, suggesting the role of dyadic factors in these "child" assessments. In the preschool classroom, location/orientation measures provide data-driven measures of children's social contact, fertile ground for vocal interactions. Both the velocity of children's movement toward one another and their social contact with one another evidence homophily: children with autism spectrum disorder, other developmental disabilities, and typically developing children were more likely to interact with children in the same group even in inclusive preschool classrooms designed to promote interchange between all children. In the vocal domain, the frequency of peer speech and the phonemic complexity of teacher speech predict the frequency and phonemic complexity of children's own speech over multiple timescales. Moreover, children's own speech predicts their assessed language abilities across disability groups, suggesting how everyday interactions facilitate development.

Non-Expert Ratings of Infant and Parent Emotion: Concordance with Expert Coding and Relevance to Early Autism Risk.

This study investigated a novel approach to obtaining data on parent and infant emotion during the Face-to-Face/Still-Face paradigm, and examined these data in light of previous findings regarding early autism risk. One-hundred and eighty eight non-expert students rated 38 parents and infant siblings of children who did (20) or did not (18) have autism spectrum disorders. Ratings averaged across 10 non-experts exhibited high concordance with expert facial-action codes for infant emotion, and 20 non-experts were required for reliable parent ratings. Findings replicated the well-established still-face effect and identified subtle risk associations consonant with results from previous investigations. The unique information offered by intuitive non-expert ratings is discussed as an alternative to complex and costly behavioral coding systems.

Cocaine exposure is associated with subtle compromises of infants' and mothers' social-emotional behavior and dyadic features of their interaction in the face-to-face still-face paradigm.

Prenatal cocaine and opiate exposure are thought to subtly compromise social and emotional development. The authors observed a large sample of 236 cocaine-exposed and 459 nonexposed infants (49 were opiate exposed and 646 nonexposed) with their mothers in the face-to-face still-face paradigm. Infant and maternal behaviors were microanalytically coded. No opiate-exposure effects were detected. However, mothers of cocaine-exposed infants showed more negative engagement than other mothers. The cocaine-exposed dyads also showed higher overall levels of mismatched engagement states than other dyads, including more negative engagement when the infants were in states of neutral engagement. Infants exposed to heavier levels of cocaine showed more passive-withdrawn negative engagement and engaged in more negative affective matching with their mothers than other infants. Although effect sizes were small, cocaine exposure, especially heavy cocaine exposure, was associated with subtly negative interchanges, which may have a cumulative impact on infants' later development and their relationships with their mothers.

All smiles are positive, but some smiles are more positive than others.

Disagreement as to whether all smiling or specific types of smiling index positive emotion early in life was addressed by examining when infants produced different types of smiling and other facial expressions. Thirteen infants were observed weekly from 1 to 6 months of age. Smiling alone--without cheek raising or mouth opening--was relatively more likely than periods without smiling both when mothers were smiling and when infants were gazing at their mothers' faces. Cheek-raise (Duchenne) smiling was relatively more likely than smiling alone only when mothers were smiling. Open-mouth (play) smiling was relatively more likely than smiling alone only when infants were gazing directly at mothers' faces. Smiling involving both cheek raising and mouth opening was relatively likely both when mothers were smiling and when infants were gazing at mothers' faces and became increasingly likely with age when both conditions co-occurred. The cheek-raise and open-mouth dimensions of smiling appear to be associated with, respectively, the amplification of processes of sharing positive affect and of visual engagement that are present to a lesser degree in smiling alone.

What's in a smile?

In positive social contexts, both adults and older infants show more Duchenne smiling (which involves high cheek raising) than non-Duchenne smiling (which does not). This study compared Duchenne and non-Duchenne smiles in early infancy for clues to their emotional significance. Infants (N = 13) from 1 to 6 months of age were videotaped weekly for 5 min in 208 face-to-face interactions with their mothers. Levels of Duchenne and non-Duchenne smiling were correlated within interactive sessions, and the 2 smiles had similar developmental trajectories. Duchenne smiles were typically preceded by non-Duchenne smiles. The results suggest these frequently contrasted types of smiles occur in similar situations and are often different temporal phases of a continuous emotional process. In contrast to adults, infant Duchenne smiles had longer durations than non-Duchenne smiles, suggesting infant smiling does not fit adult models of emotional functioning.

The Bayley Scales of Infant Development. II: Where to start?

This study examines whether the Bayley Scales of Infant Development-Second Edition (Bayley II) Mental Scale scores vary on the basis of which item set is considered the starting point of an infant's assessment. The Bayley II was administered to 78 12-month-old infants by certified examiners beginning with the 12-month age item set. A second certified examiner then administered 10 additional items that completed the 11-month and 13-month age item sets. Of the 78 infants tested, 73 (94%) met basal and ceiling criteria in all three item sets. Three separate Mental Developmental Index (MDI) scores were calculated using 12-month norms for each subject, which were based on the raw scores generated from the 11-, 12-, and 13-month age item sets. Scores calculated on the 11-month set were significantly lower than those on the 12-month set, which were in turn significantly lower than those on the 13-month set. When tested on the 11-month instead of on the 12-month item set, twice as many infants received lower than normal (< 85) MDI scores, indicating an impact on referability decisions. Minor adjustments in administration of the Bayley II, such as those based on assumptions regarding an infant's current level of functioning, significantly affect infant test scores and eligibility for follow-up services. Standardized use of this test should minimize variability in test scores.

An event-based analysis of the coordination of early infant vocalizations and facial actions.

This study used an event-based approach to provide empirical evidence regarding the nature of coordination in 3- and 6-month-old infants. Vocalizations and facial actions of 12 normally developing infants interacting with their caregivers were coded. Coded vocalizations and facial actions were considered coordinated when they temporally overlapped. Results indicate that infants coordinated their vocalizations and facial actions more than expected by chance. Coordinated events were governed by 2 sequence patterns. When 2 communicative events were temporally associated across modalities, 1 event tended to be completely embedded within the other, and vocalizations tended to end before facial actions. This study provides new information about how infant communication is structured, confirms results from other coordination studies, and describes a new method for analysis of event-based data.