Infants have a strong tendency to look at faces. We examined individual variations in this attentional bias in 7-month-old infants by using a face-distractor competition paradigm and tested in a longitudinal sample whether these variations were associated with outcomes reflecting social behavior at 24 and 48 months of age (i.e., spontaneous helping, emotion understanding, mentalizing, and callous-unemotional traits; N = 100-138). The results showed a robust and distinct attention bias to faces at 7 months, particularly when faces were displaying a fearful expression. This bias declined between 7 and 24 months and there were no significant correlations in attention dwell times between 7 and 24 months of age. Variations in attention to faces at 7 months were not associated with emotion understanding or mentalizing abilities at 48 months of age, but increased attention to faces at 7 months (regardless of facial expression) was related to more frequent helping responses at 24 months and reduced callous-unemotional traits at 48 months of age. Thus, while the results fail to associate infants' face bias with later-emerging emotion understanding and mentalizing capacities, they are consistent with a model whereby increased attention to faces in infancy is linked with the development of affective empathy and responsivity to others' needs.

Background: Cross-species evidence suggests that genetic and experiential factors act early in development to establish individual emotional traits, but little is known about the mechanisms that emerge during this period to mediate long-term outcomes. Here, we tested the hypothesis that known genetic and environmental risk conditions may heighten infants' natural tendency to attend to threat-alerting stimuli, resulting in a cognitive bias that may contribute to emotional vulnerability. Methods: Data from two samples of 5-7-month-old infants (N = 139) were used to examine whether established candidate variations in the serotonin-system genes, i.e., TPH2 SNP rs4570625 (-703 G/T) and HTR1A SNP rs6295 (-1019 G/C), and early rearing condition (maternal stress and depressive symptoms) are associated with alterations in infants' attention to facial expressions. Infants were tested with a paradigm that assesses the ability to disengage attention from a centrally presented stimulus (a nonface control stimulus or a neutral, happy, or fearful facial expression) toward the location of a new stimulus in the visual periphery (a geometric shape). Results: TPH2 -703 T-carrier genotype (i.e., TT homozygotes and heterozygotes), presence of maternal stress and depressive symptoms, and a combination of the T-carrier genotype and maternal depressive symptoms were associated with a relatively greater difficulty disengaging attention from fearful facial expressions. No associations were found with infants' temperamental traits. Conclusions: Alterations in infants' natural attentional bias toward fearful facial expressions may emerge prior to the manifestation of emotional and social behaviors and provide a sensitive marker of early emotional development.

Saccadic reaction time (SRT) is a widely used dependent variable in eye-tracking studies of human cognition and its disorders. SRTs are also frequently measured in studies with special populations, such as infants and young children, who are limited in their ability to follow verbal instructions and remain in a stable position over time. In this article, we describe a library of MATLAB routines (Mathworks, Natick, MA) that are designed to (1) enable completely automated implementation of SRT analysis for multiple data sets and (2) cope with the unique challenges of analyzing SRTs from eye-tracking data collected from poorly cooperating participants. The library includes preprocessing and SRT analysis routines. The preprocessing routines (i.e., moving median filter and interpolation) are designed to remove technical artifacts and missing samples from raw eye-tracking data. The SRTs are detected by a simple algorithm that identifies the last point of gaze in the area of interest, but, critically, the extracted SRTs are further subjected to a number of postanalysis verification checks to exclude values contaminated by artifacts. Example analyses of data from 5- to 11-month-old infants demonstrated that SRTs extracted with the proposed routines were in high agreement with SRTs obtained manually from video records, robust against potential sources of artifact, and exhibited moderate to high test–retest stability. We propose that the present library has wide utility in standardizing and automating SRT-based cognitive testing in various populations. The MATLAB routines are open source and can be downloaded from http://www.uta.fi/med/icl/methods.html.Electronic supplementary materialThe online version of this article (doi:10.3758/s13428-014-0473-z) contains supplementary material, which is available to authorized users.

Recent studies suggest that parental caregiving is associated with adaptive changes in neurocognitive responses to emotional cues and oxytocin function, possibly reflecting the increased need of parents to monitor infants’ emotional states. In the current study, we investigated whether the changes associated with motherhood and oxytocin receptor genetic variation rs53576 are specific to the processing of infant cues as opposed to a more general increase in responsiveness to emotional cues. We measured event-related brain potentials (ERPs) and behavioral recognition responses from mothers of young infants (n = 48) and nulliparous females (n = 46) to infant and adult faces displaying strong and mild intensity emotional expressions. Mothers and GG allele carriers of the OXTR gene showed an early latency (∼100 ms) differential frontal ERP response to strong intensity facial expressions, and mothers also showed modulation of the posterior EPN waveform by negative valence. The early frontal ERP modulation was associated with faster emotion recognition performance across participants. Most importantly, these effects were highly specific to infant facial expressions. The results point to a dissociable neurocognitive system that is involved in monitoring infants’ emotional cues and may be important in supporting parental caregiving in humans.

Biases in attention towards facial cues during infancy may have an important role in the development of social brain networks. The current study used a longitudinal design to examine the stability of infants' attentional biases towards facial expressions and to elucidate how these biases relate to emerging cortical sensitivity to facial expressions. Event-related potential (ERP) and attention disengagement data were acquired in response to the presentation of fearful, happy, neutral, and phase-scrambled face stimuli from the same infants at 5 and 7 months of age. The tendency to disengage from faces was highly consistent across both ages. However, the modulation of this behavior by fearful facial expressions was uncorrelated between 5 and 7 months. In the ERP data, fear-sensitive activity was observed over posterior scalp regions, starting at the latency of the N290 wave. The scalp distribution of this sensitivity to fear in ERPs was dissociable from the topography of face-sensitive modulation within the same latency range. While attentional bias scores were independent of co-registered ERPs, attention bias towards fearful faces at 5 months of age predicted the fear-sensitivity in ERPs at 7 months of age. The current results suggest that the attention bias towards fear could be involved in the developmental tuning of cortical networks for social signals of emotion.