Mother-infant interaction characteristics associate with infant falling reactivity and child peer problems at pre-school age.

This longitudinal study investigated the associations between mother-infant interaction characteristics at 9 months of age, maternal mental health, infant temperament in the first year postpartum, and child behaviour at 3 years of age. The infants (N = 54, 22 females) mainly had White British ethnic backgrounds (85.7%). Results showed that i) mother-infant dyadic affective mutuality positively correlated with infant falling reactivity, suggesting that better infant regulatory skills are associated with the dyad's ability to share and understand each other's emotions; and ii) maternal respect for infant autonomy predicted fewer child peer problems at 3 years of age, suggesting that maternal respect for the validity of the infant's individuality promotes better social and emotional development in early childhood.

Infant visual preference for the mother's face and longitudinal associations with emotional reactivity in the first year of life.

Past research has focused on infants' visual preference for the mother's face, however it is still unknown how these responses change over time and what factors associate with such changes. A longitudinal study (N ~ 60) was conducted to investigate the trajectories of infant visual preference for the mother's face and how these are related to the development of emotional reactivity in the first year of life. Two face stimuli (i.e., the infant's mother and a consistent stranger face) were used in a visual preference task at 2 weeks, 4, 6, and 9 months of age. At each time point, mothers were asked to complete a measure of infant temperament via standardised questionnaires. Our results show that while at 2 weeks, 4 months and 9 months of age infants looked equally at both faces, infants at 6 months looked significantly longer at their mother's face. We also observed prospective associations with emotional reactivity variables so that infants who looked longer at the mother's face at 6 months showed higher falling reactivity, i.e. a better ability to recover from distress, at 9 months. We discuss these findings in light of the roles that both infant development and the caregiver play in emerging emotion regulation capacities during the first year of life.

Maternal depressive symptoms and infant temperament in the first year of life predict child behavior at 36 months of age.

In a longitudinal study, mothers (N = 50) self-reported on their depressive symptoms (DS) and their child's behavior during the first year and at 36 months postpartum. Maternal DS during infancy were associated with child conduct problems (CP), suggesting a long-term association between maternal mental health and the development of child behavior. Infant temperament was also associated with child behavior so that negative affect predicted child CP, while infant surgency was associated with later hyperactivity-inattention. This study contributes to the literature by jointly assessing the role of maternal DS and infant temperament and showing that these are independent predictors of childhood behavior.

How do bodies become special? Electrophysiological evidence for the emergence of body-related cortical processing in the first 14 months of life.

There is general consensus that the representation of the human face becomes functionally specialized within the first few months of an infant's life. The literature is divided, however, on the question whether the specialized representation of the remainder of the human body form follows a similarly rapid trajectory or emerges more slowly and in line with domain-general learning mechanisms. Our study investigates visual event-related potentials (ERPs) in adults (P1 and N170) and infants (P1, N290, P400, and Nc) of 3 age groups (3.5, 10, and 14 months) to compare the emergence of face- and body-structural encoding. Our findings show that visual ERPs were absent (P1, N290, P400) or smaller (Nc) for bodies than for faces at 3.5 months. At older ages, P400 was smaller (10 months) and peaked later (14 months) for bodies than for faces. Effects of stimulus orientation were not reliably found until 14 months, where they were more broadly distributed for faces than for bodies. Inverted faces, but not bodies, produced an adult-like pattern for P400 at 14 months, emphasizing the role of P400 as the precursor of the adult N170. Importantly, our findings argue that structural encoding of the human body form emerges later in infancy and is qualitatively different from the structural encoding for faces. This is commensurate with infant motor development and the experience of viewing complete body shapes later than faces. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Recruitment of Language-, Emotion- and Speech-Timing Associated Brain Regions for Expressing Emotional Prosody: Investigation of Functional Neuroanatomy with fMRI.

We aimed to progress understanding of prosodic emotion expression by establishing brain regions active when expressing specific emotions, those activated irrespective of the target emotion, and those whose activation intensity varied depending on individual performance. BOLD contrast data were acquired whilst participants spoke non-sense words in happy, angry or neutral tones, or performed jaw-movements. Emotion-specific analyses demonstrated that when expressing angry prosody, activated brain regions included the inferior frontal and superior temporal gyri, the insula, and the basal ganglia. When expressing happy prosody, the activated brain regions also included the superior temporal gyrus, insula, and basal ganglia, with additional activation in the anterior cingulate. Conjunction analysis confirmed that the superior temporal gyrus and basal ganglia were activated regardless of the specific emotion concerned. Nevertheless, disjunctive comparisons between the expression of angry and happy prosody established that anterior cingulate activity was significantly higher for angry prosody than for happy prosody production. Degree of inferior frontal gyrus activity correlated with the ability to express the target emotion through prosody. We conclude that expressing prosodic emotions (vs. neutral intonation) requires generic brain regions involved in comprehending numerous aspects of language, emotion-related processes such as experiencing emotions, and in the time-critical integration of speech information.

Theta- and alpha-band EEG activity in response to eye gaze cues in early infancy.

In order to elucidate the development of how infants use eye gaze as a referential cue, we investigated theta and alpha oscillations in response to object-directed and object-averted eye gaze in infants aged 2, 4, 5, and 9months. At 2months of age, no difference between conditions was found. In 4- and 9-month-olds, alpha-band activity desynchronized more in response to faces looking at objects compared to faces looking away from objects. Theta activity in 5-month-old infants differed between conditions with more theta synchronization for object-averted eye gaze. Whereas alpha desynchronization might reflect mechanisms of early social object learning, theta is proposed to imply activity in the executive attention network. The interplay between alpha and theta activity represents developmental changes in both kinds of processes during early infancy.

Infants Need More Variety - Increased Data Acquisition with Reduced Participant Attrition in Infant ERP Studies.

Infant ERP studies often feature high attrition rates with large numbers of trials excluded from statistical analyses. The number of experimental conditions is conventionally limited to reduce the test-sessions' durations and to ensure that reasonable trial-numbers will be obtained for each condition. Here, we designed an ERP study involving eight conditions originating from three previously published studies and presented them to 18 1-year-olds. We expected to replicate original results at least partly. Additionally, we were interested in the effect this novel method of stimulus presentation would have on infant attention. Due to the requirement for sustained attention, interest may decrease. Alternatively, the stimulus-variability may extend attention, allowing the acquisition of more valid trials. Our main finding was that the variability of the stimulus presentation sustained the infants' attention beyond normal parameters. This is apparent from the markedly increased number of artifact-free trials obtained and from the substantially decreased attrition rates. Results from a gap-/no gap-task were fully replicated whereas others, related to face-processing, were replicated in part. Additionally, effects that were not reported in the original studies were found. This is most probably due to interference in the information processing between these conditions. The results show that presenting infants with varied stimuli extends their attention, allowing the acquisition of at least four times more data than via current infant ERP methods. However, stimuli from separate sub-experiments must be cognitively and perceptually distinct, otherwise contamination between related factors will occur.

A meta-analysis investigating factors underlying attrition rates in infant ERP studies.

In this meta-analysis, we examined interrelationships between characteristics of infant event-related potential (ERP) studies and their attrition rates. One-hundred and forty-nine published studies provided information on 314 experimental groups of which 181 provided data on attrition. A random effects meta-analysis revealed a high average attrition rate of 49.2%. Additionally, we used meta-regression for 178 groups with attrition data to analyze which variables best explained attrition variance. Our main findings were that the nature of the stimuli-visual, auditory, or combined as well as if stimuli were animated-influenced exclusion rates from the final analysis and that infant age did not alter attrition rates.

Infant ERP amplitudes change over the course of an experimental session: Implications for cognitive processes and methodology.

Event-related Potentials (ERP) studies are a widely used methodology to investigate the early cognitive development in infants of all age ranges. We examined changes in amplitude contribution in a set of previously published data (see [4]) in relation to the Negative component as a function of number of trials contributing to each individual average and with time as a co-variate to that contribution. With only seven trials contributing to each individual's average the Nc for the object-directed condition was significantly more negative than the one for the averted-gaze condition, which is the opposite of the effect reported in Hoehl et al. [4]. The analysis including time as a co-variate revealed that the effect did not alter according to the amount of time taken during the experiment to collect each trial, suggesting that data of the quality needed to contribute to the ERP is itself a measure of time varying components of the experimental session. We conclude that infants initially allocate more attentional resources to object-directed gaze. This suggests that the temporal dynamics of infant ERP violates assumptions present in adult ERP, and that differences between conditions in relatively few trials inform us of cognitive capacities during infancy.

Joint attention helps infants learn new words: event-related potential evidence.

This study investigated the role of joint attention in infants' word learning. Infants aged 18-21 months were taught new words in two social contexts, joint attention (eye contact, positive tone of voice) or non-joint attention (no eye contact, neutral tone of voice). Event-related potentials were measured as the infants saw objects either congruent or incongruent with the taught words. For both social contexts, an early negativity was observed for the congruent condition, reflecting a phonological-lexical priming effect between objects and the taught words. In addition, for the joint attention, the incongruent condition elicited a late, widely distributed negativity, attributed to semantic integration difficulties. Thus, social cues have an impact on how words are learned and represented in a child's mental lexicon.

Direct eye contact influences the neural processing of objects in 5-month-old infants.

Do 5-month-old infants show differences in processing objects as a function of a prior interaction with an adult? Using a live ERP paradigm we assessed this question utilizing a within-subjects design. Infants saw objects during two pretest phases with an adult experimenter. We recorded event-related potentials to the presentation of objects following the interactive pretest phases. Experimental conditions differed only in the nature of eye contact between the infant and the experimenter during the pretests. In one condition the experimenter engaged the infant with direct eye contact. In a second condition the experimenter looked only at the infant's chest. We found that the negative component, related to attentional processes, showed differences between experimental conditions in left fronto-central locations. These data show that 5-month-old infants allocate more attention to objects that have been previously seen during direct eye-contact interaction. In addition, these results clarify the functional nature of the negative component.