Fearful but not happy expressions boost face detection in human infants

Interoceptive sensibility predicts the ability to infer others' emotional states

Emotional sensations and inferring another's emotional states have been suggested to depend on predictive models of the causes of bodily sensations, so-called interoceptive inferences. In this framework, higher sensibility for interoceptive changes (IS) reflects higher precision of interoceptive signals. The present study examined the link between IS and emotion recognition, testing whether individuals with higher IS recognize others' emotions more easily and are more sensitive to learn from biased probabilities of emotional expressions. We recorded skin conductance responses (SCRs) from forty-six healthy volunteers performing a speeded-response task, which required them to indicate whether a neutral facial expression dynamically turned into a happy or fearful expression. Moreover, varying probabilities of emotional expressions by their block-wise base rate aimed to generate a bias for the more frequently encountered emotion. As a result, we found that individuals with higher IS showed lower thresholds for emotion recognition, reflected in decreased reaction times for emotional expressions especially of high intensity. Moreover, individuals with increased IS benefited more from a biased probability of an emotion, reflected in decreased reaction times for expected emotions. Lastly, weak evidence supporting a differential modulation of SCR by IS as a function of varying probabilities was found. Our results indicate that higher interoceptive sensibility facilitates the recognition of emotional changes and is accompanied by a more precise adaptation to emotion probabilities.

Prenatal Glucocorticoid-Exposed Infants Do Not Show an Age-Typical Fear Bias at 8 Months of Age - Preliminary Findings From the FinnBrain Birth Cohort Study

Synthetic glucocorticoids (sGC) are frequently administered to pregnant women at risk for preterm delivery to promote fetal lung maturation. Despite their undeniable beneficial effects in lung maturation, the impact of these hormones on developing brain is less clear. Recent human studies suggest that emotional and behavioral disorders are more common among sGC-exposed vs. non-exposed children, but the literature is sparse and controversial. We investigated if prenatal sGC exposure altered fear bias, a well-established infant attention phenotype, at 8-months. We used eye tracking and an overlap paradigm with control, neutral, happy, and fearful faces, and salient distractors, to evaluate infants’ attention disengagement from faces, and specifically from fearful vs. neutral and happy faces (i.e., a fear bias) in a sample (N = 363) of general population from the FinnBrain Birth Cohort Study. sGC exposed infants (N = 12) did not differ from non-exposed infants (N = 351) in their overall probability of disengagement in any single stimulus condition. However, in comparison with non-exposed infants, they did not show the age-typical fear bias and this association remained after controlling for confounding factors such as prematurity, gestational age at birth, birth weight, sex, and maternal postnatal depressive symptoms. Prenatal sGC exposure may alter emotional processing in infants. The atypical emotion processing in turn may be a predictor of emotional problems later in development. Future longitudinal studies are needed in order to evaluate the long-term consequences of sGC exposure for the developing brain.

Maternal odor reduces the neural response to fearful faces in human infants

Maternal odor is known to play an important role in mother-infant-interaction in many altricial species such as rodents. However, we only know very little about its role in early human development. The present study therefore investigated the impact of maternal odor on infant brain responses to emotional expression. We recorded the electroencephalographic (EEG) signal of seven-month-old infants watching happy and fearful faces. Infants in two control groups exposed to no specific odor (control 1) or the odor of a different infant’s mother (control 2) showed the expected EEG fear response. Crucially, this response was markedly absent in the experimental group exposed to their mother’s odor. Thus, infants respond differently to fear signals in the presence of maternal odor. Our data therefore suggest that maternal odor can be a strong modulator of social perception in human infants.

The developmental origins of subliminal face processing

Sensitive responding to facial information is of key importance during human social interactions. Research shows that adults glean much information from another person's face without conscious perception, attesting to the robustness of face processing in the service of adaptive social functioning. Until recently, it was unclear whether such subliminal face processing is an outcome of extensive learning, resulting in adult face processing skills, or an early defining feature of human face processing. Here, we review recent research examining the early ontogeny and brain correlates of subliminal face processing, demonstrating that subliminal face processing: (1) emerges during the first year of life; (2) is multifaceted in response to transient (gaze, emotion) and stable (trustworthiness) facial cues; (3) systematically elicits frontal brain responses linked to attention allocation. The synthesized research suggests that subliminal face processing emerges early in human development and thus may play a foundational role during human social interactions. This offers a fresh look at the ontogenetic origins of unconscious face processing and informs theoretical accounts of human sociality.

Three-month-old infants show enhanced behavioral and neural sensitivity to fearful faces

An important feature of the development of emotion recognition in infants is the emergence of a robust attentional bias for fearful faces. There is some debate about when this enhanced sensitivity to fearful expressions develops. The current study explored whether 3-month-olds demonstrate differential behavioral and neural responding to happy and fearful faces. Three-month-old infants (n = 69) participated in a behavioral task that assessed whether they show a visual preference for fearful faces and an event-related potential (ERP) task that assessed their neural responses to fearful and happy faces. Infants showed a looking preference for fearful over happy faces. They also showed differential neural responding over occiptotemporal regions that have been implicated in face perception (i.e., N290, P400), but not over frontocentral regions that have been implicated in attentional processes (i.e., Nc). These findings suggest that 3-month-olds display an early perceptual sensitivity to fearful faces, which may presage the emergence of the attentional bias for fearful faces in older infants. Tracking the ontogeny of this phenomenon is necessary to understand its relationship with later developmental outcomes.

Developing an Understanding of Emotion Categories: Lessons from Objects

How and when infants and young children begin to develop emotion categories is not yet well understood. Research has largely treated the learning problem as one of identifying perceptual similarities among exemplars (typically posed, stereotyped facial configurations). However, recent meta-analyses and reviews converge to suggest that emotion categories are abstract, involving high-dimensional and situationally variable instances. In this paper we consult research on the development of abstract object categorization to guide hypotheses about how infants might learn abstract emotion categories because the two domains present infants with similar learning challenges. In particular, we consider how a developmental cascades framework offers opportunities to understand how and when young children develop emotion categories.

The Sensitivity to Threat and Affiliative Reward (STAR) model and the development of callous-unemotional traits

Research implicates callous-unemotional (CU) traits (i.e., lack of empathy, prosociality, and guilt, and reduced sensitivity to others' emotions) in the development of severe and persistent antisocial behavior. To improve etiological models of antisocial behavior and develop more effective treatments, we need a better understanding of the origins of CU traits. In this review, we discuss the role of two psychobiological and mechanistic precursors to CU traits: low affiliative reward (i.e., deficits in seeking out or getting pleasure from social bonding and closeness with others) and low threat sensitivity (i.e., fearlessness to social and non-social threat). We outline the Sensitivity to Threat and Affiliative Reward (STAR) model and review studies that have examined the development of affiliative reward and threat sensitivity across animal, neuroimaging, genetic, and behavioral perspectives. We next evaluate evidence for the STAR model, specifically the claim that CU traits result from deficits in both affiliative reward and threat sensitivity. We end with constructive suggestions for future research to test the hypotheses generated by the STAR model.

Quantifying Facial Expression Intensity and Signal Use in Deaf Signers

We live in a world of rich dynamic multisensory signals. Hearing individuals rapidly and effectively integrate multimodal signals to decode biologically relevant facial expressions of emotion. Yet, it remains unclear how facial expressions are decoded by deaf adults in the absence of an auditory sensory channel. We thus compared early and profoundly deaf signers (n = 46) with hearing nonsigners (n = 48) on a psychophysical task designed to quantify their recognition performance for the six basic facial expressions of emotion. Using neutral-to-expression image morphs and noise-to-full signal images, we quantified the intensity and signal levels required by observers to achieve expression recognition. Using Bayesian modeling, we found that deaf observers require more signal and intensity to recognize disgust, while reaching comparable performance for the remaining expressions. Our results provide a robust benchmark for the intensity and signal use in deafness and novel insights into the differential coding of facial expressions of emotion between hearing and deaf individuals.

Do Preverbal Infants Understand Discrete Facial Expressions of Emotion?

An ongoing debate in affective science concerns whether certain discrete, “basic” emotions have evolutionarily based signals (facial expressions) that are easily, universally, and (perhaps) innately identified. Studies with preverbal infants (younger than 24 months) have the potential to shed light on this debate. This review summarizes what is known about preverbal infants’ understanding of discrete emotional facial expressions. Overall, while many studies suggest that preverbal infants differentiate positive and negative facial expressions, few studies have tested whether infants understand discrete emotions (e.g., anger vs. disgust). Moreover, results vary greatly based on methodological factors. This review also (a) discusses how language may influence the development of emotion understanding, and (b) proposes a new developmental hypothesis for infants’ discrete emotion understanding.

Epigenetic modification of the oxytocin receptor gene is associated with emotion processing in the infant brain

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First developmental neuroimaging epigenetics study with human infants.

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Oxytocin receptor gene methylation (OXTRm) assessed in a large sample of infants.

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OXTRm predicts inferior frontal brain responses to emotional faces using fNIRS.

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Higher OXTRm linked to enhanced brain responses to angry and fearful faces.

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OXTRm contributes to variability in social brain function early in ontogeny.

The neural capacity to discriminate between emotions emerges early in development, though little is known about specific factors that contribute to variability in this vital skill during infancy. In adults, DNA methylation of the oxytocin receptor gene (OXTRm) is an epigenetic modification that is variable, predictive of gene expression, and has been linked to autism spectrum disorder and the neural response to social cues. It is unknown whether OXTRm is variable in infants, and whether it is predictive of early social function. Implementing a developmental neuroimaging epigenetics approach in a large sample of infants (N = 98), we examined whether OXTRm is associated with neural responses to emotional expressions. OXTRm was assessed at 5 months of age. At 7 months of age, infants viewed happy, angry, and fearful faces while functional near-infrared spectroscopy was recorded. We observed that OXTRm shows considerable variability among infants. Critically, infants with higher OXTRm show enhanced responses to anger and fear and attenuated responses to happiness in right inferior frontal cortex, a region implicated in emotion processing through action-perception coupling. Findings support models emphasizing oxytocin’s role in modulating neural response to emotion and identify OXTRm as an epigenetic mark contributing to early brain function.

Recognition of facial emotions of varying intensities by three-year-olds

Early facial emotion recognition is hypothesized to be critical to later social functioning. However, relatively little is known about the typical intensity thresholds for recognizing facial emotions in preschoolers, between 2 and 4 years of age. This study employed a behavioral sorting task to examine the recognition of happy, fearful, and angry expressions of varying intensity in a large sample of 3-year-old children (N = 208). Thresholds were similar for all expressions; accuracy, however, was significantly lower for fear. Fear and anger expressions above threshold were significantly more confused with one another than with other expressions. In contrast, neutral faces were significantly more often interpreted as happy than as angry or fearful. These results provide a comparison point for future studies of early facial emotion recognition in typical and atypical populations of children in this age group. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Maternal Depressive Symptoms During the Pre- and Postnatal Periods and Infant Attention to Emotional Faces

We examined how infants' attentional disengagement from happy, fearful, neutral, and phase-scrambled faces at 8 months, as assessed by eye tracking, is associated with trajectories of maternal depressive symptoms from early pregnancy to 6 months postpartum (decreasing n = 48, increasing n = 34, and consistently low symptom levels n = 280). The sample (mother-infant dyads belonging to a larger FinnBrain Birth Cohort Study) was collected between 5/2013-6/2016. The overall disengagement probability from faces to distractors was not related to maternal depressive symptoms, but fear bias was heightened in infants whose mothers reported decreasing or increasing depressive symptoms. Exacerbated attention to fearful faces in infants of mothers with depressive symptoms may be independent of the timing of the symptoms in the pre- and postnatal stages.

Fearful but not happy expressions boost face detection in human infants

Human adults show an attentional bias towards fearful faces, an adaptive behaviour that relies on amygdala function. This attentional bias emerges in infancy between 5 and 7 months, but the underlying developmental mechanism is unknown. To examine possible precursors, we investigated whether 3.5-, 6- and 12-month-old infants show facilitated detection of fearful faces in noise, compared to happy faces. Happy or fearful faces, mixed with noise, were presented to infants (N = 192), paired with pure noise. We applied multivariate pattern analyses to several measures of infant looking behaviour to derive a criterion-free, continuous measure of face detection evidence in each trial. Analyses of the resulting psychometric curves supported the hypothesis of a detection advantage for fearful faces compared to happy faces, from 3.5 months of age and across all age groups. Overall, our data show a readiness to detect fearful faces (compared to happy faces) in younger infants that developmentally precedes the previously documented attentional bias to fearful faces in older infants and adults.