Further evidence of early development of attention to dynamic facial emotions: Reply to Grossmann and Jessen

An integrative review: Human chemosensory communication in the parent-child relationship

Body odors serve as signals of kinship, with parents exhibiting a preference for the scent of their infants, and vice versa. The reciprocal perception of body odors can promote bonding through two mechanisms. Firstly, as an indirect pathway, through associative chemosensory learning, which leads to changes in proximity-seeking behaviors. Secondly, as a direct pathway, by eliciting the display of positive emotions, thereby reinforcing the mutual bond. Both mechanisms weaken as the child undergoes development due to changes in body odor expression and perception. This comprehensive review provides an overview of the current literature on chemosignals in the parent-child relationship, highlighting their significance in facilitating dyadic communication throughout the developmental span. Furthermore, future research perspectives are outlined to gain a better understanding of these benefits and, on the long run, derive potential interventions to strengthen parent child attachment.

Maternal stress and development of infant attention to threat-related facial expressions

Attentional biases to threat-related stimuli, such as fearful and angry facial expressions, are important to survival and emerge early in development. Infants demonstrate an attentional bias to fearful facial expressions by 5-7 months of age and an attentional bias toward anger by 3 years of age that are modulated by experiential factors. In a longitudinal study of 87 mother-infant dyads from families predominantly experiencing low income, we examined whether maternal stress and depressive symptoms were associated with trajectories of attentional biases to threat, assessed during an attention disengagement eye-tracking task when infants were 6-, 9-, and 12-month old. By 9 months, infants demonstrated a generalized bias toward threat (both fearful and angry facial expressions). Maternal perceived stress was associated with the trajectory of the bias toward angry facial expressions between 6 and 12 months. Specifically, infants of mothers with higher perceived stress exhibited a greater bias toward angry facial expressions at 6 months that decreased across the next 6 months, compared to infants of mothers with lower perceived stress who displayed an increased bias to angry facial expressions over this age range. Maternal depressive symptoms and stressful life events were not associated with trajectories of infant attentional bias to anger or fear. These findings highlight the role of maternal perceptions of stress in shaping developmental trajectories of threat-alerting systems.

Sensorimotor Activity and Network Connectivity to Dynamic and Static Emotional Faces in 7-Month-Old Infants

The present study investigated whether, as in adults, 7-month-old infants’ sensorimotor brain areas are recruited in response to the observation of emotional facial expressions. Activity of the sensorimotor cortex, as indexed by µ rhythm suppression, was recorded using electroencephalography (EEG) while infants observed neutral, angry, and happy facial expressions either in a static (N = 19) or dynamic (N = 19) condition. Graph theory analysis was used to investigate to which extent neural activity was functionally localized in specific cortical areas. Happy facial expressions elicited greater sensorimotor activation compared to angry faces in the dynamic experimental condition, while no difference was found between the three expressions in the static condition. Results also revealed that happy but not angry nor neutral expressions elicited a significant right-lateralized activation in the dynamic condition. Furthermore, dynamic emotional faces generated more efficient processing as they elicited higher global efficiency and lower networks’ diameter compared to static faces. Overall, current results suggest that, contrarily to neutral and angry faces, happy expressions elicit sensorimotor activity at 7 months and dynamic emotional faces are more efficiently processed by functional brain networks. Finally, current data provide evidence of the existence of a right-lateralized activity for the processing of happy facial expressions.

Infants are sensitive to cultural differences in emotions at 11 months

A myriad of emotion perception studies has shown infants' ability to discriminate different emotional categories, yet there has been little investigation of infants' perception of cultural differences in emotions. Hence little is known about the extent to which culture-specific emotion information is recognised in the beginning of life. Caucasian Australian infants of 10-12 months participated in a visual-paired comparison task where their preferential looking patterns to three types of infant-directed emotions (anger, happiness, surprise) from two different cultures (Australian, Japanese) were examined. Differences in racial appearances were controlled. Infants exhibited preferential looking to Japanese over Caucasian Australian mothers' angry and surprised expressions, whereas no difference was observed in trials involving East-Asian Australian mothers. In addition, infants preferred Caucasian Australian mothers' happy expressions. These findings suggest that 11-month-olds are sensitive to cultural differences in spontaneous infant-directed emotional expressions when they are combined with a difference in racial appearance.

Exploring emotional face processing in 5-month-olds: The relation with quality of parent-child interaction and spatial frequencies

It is unclear whether infants differentially process emotional faces in the brain at 5 months of age. Contradictory findings of previous research indicate that additional factors play a role in this process. The current study investigated whether five-month-old infants show differential brain activity between emotional faces. Furthermore, we explored the relation between emotional face processing and (I) stimulus characteristics, specifically the spatial frequency content, and (II) parent, child, and dyadic qualities of interaction characteristics. Face-sensitive components (i.e., N290, P400, Nc) in response to neutral and fearful faces that contained only lower or higher spatial frequencies were assessed. Quality of parent-child interaction was assessed with the Manchester Assessment of Caregiver Infant Interaction (MACI). The results show that, as a full group, none of the components differed between emotional expressions. However, when splitting the group based on median MACI scores, infants who showed high quality of interaction (i.e., more attentiveness to caregiver, positive and negative affect, and liveliness) processed emotions differently, whereas infants who showed low quality did not. These results indicate that a sub-group of infants show differential emotional face processing at 5 months of age, which seem to relate to quality of their behavior during the parent-child interaction.

The Relationship Between Facial Expression and Cognitive Function in Patients With Depression

Objective: Considerable evidence has shown that facial expression recognition ability and cognitive function are impaired in patients with depression. We aimed to investigate the relationship between facial expression recognition and cognitive function in patients with depression.

Methods: A total of 51 participants (i.e., 31 patients with depression and 20 healthy control subjects) underwent facial expression recognition tests, measuring anger, fear, disgust, sadness, happiness, and surprise. The Chinese version of the MATRICS Consensus Cognitive Battery (MCCB), which assesses seven cognitive domains, was used.

Results: When compared with a control group, there were differences in the recognition of the expressions of sadness (p = 0.036), happiness (p = 0.041), and disgust (p = 0.030) in a depression group. In terms of cognitive function, the scores of patients with depression in the Trail Making Test (TMT; p < 0.001), symbol coding (p < 0.001), spatial span (p < 0.001), mazes (p = 0.007), the Brief Visuospatial Memory Test (BVMT; p = 0.001), category fluency (p = 0.029), and continuous performance test (p = 0.001) were lower than those of the control group, and the difference was statistically significant. The accuracy of sadness and disgust expression recognition in patients with depression was significantly positively correlated with cognitive function scores. The deficits in sadness expression recognition were significantly correlated with the TMT (p = 0.001, r = 0.561), symbol coding (p = 0.001, r = 0.596), maze (p = 0.015, r = 0.439), and the BVMT (p = 0.044, r = 0.370). The deficits in disgust expression recognition were significantly correlated with impairments in the TMT (p = 0.005, r = 0.501) and symbol coding (p = 0.001, r = 0.560).

Conclusion: Since cognitive function is impaired in patients with depression, the ability to recognize negative facial expressions declines, which is mainly reflected in processing speed, reasoning, problem-solving, and memory.

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.

Sex-specific scanning in infancy: Developmental changes in the use of face/head and body information

The current investigation sought to differentiate between contrasting perspectives of body knowledge development by determining whether infants' adult-like scanning of male and female bodies is dependent on relevant information from the face/head alone, the body alone, or a combination of both sources. Scanning patterns of 3.5-, 6.5-, and 9-month-olds (N = 80) in response to images that contained information relevant to sex classification in either the face/head or the body were examined. The results indicate that sex-specific scanning in the presence of only one source of relevant information (i.e., face/head or body) is present only at 9 months. Thus, although sex-specific scanning of bodies emerges as early as 3.5 months, information from both faces/heads and bodies is required until sometime between 6.5 and 9 months of age. These findings constrain theories of the development of social perception by documenting the complex interplay between body and face/head processing early in life.

Threat-related Attention Bias in Socioemotional Development: A Critical Review and Methodological Considerations

Cross-sectional evidence suggests that attention bias to threat is linked to anxiety disorders and anxiety vulnerability in both children and adults. However, there is a lack of developmental evidence regarding the causal mechanisms through which attention bias to threat might convey risks for socioemotional problems, such as anxiety. Gaining insights into this question demands longitudinal research to track the complex interplay between threat-related attention and socioemotional functioning. Developing and implementing reliable and valid assessments tools is essential to this line of work. This review presents theoretical accounts and empirical evidence from behavioral, eye-tracking, and neural assessments of attention to discuss our current understanding of the development of normative threat-related attention in infancy, as well as maladaptive threat-related attention patterns that may be associated with the development of anxiety. This review highlights the importance of measuring threat-related attention using multiple attention paradigms at multiple levels of analysis. In order to understand if and how threat-related attention bias in real-life, social interactive contexts can predict socioemotional development outcomes, this review proposes that future research cannot solely rely on screen-based paradigms but needs to extend the assessment of threat-related attention to naturalistic settings. Mobile eye-tracking technology provides an effective tool for capturing threat-related attention processes in vivo as children navigate fear-eliciting environments and may help us uncover more proximal bio-psycho-behavioral markers of anxiety.

Dichotomous Perception of Animal Categories in Infancy

Although there is a wealth of knowledge on categorization early in life, there are still many unanswered questions about the nature of category representation in infancy. For example, it is unclear whether infants are sensitive to boundaries between complex categories, such as types of animals, or whether young infants exhibit such sensitivity without explicit experience in the lab. Using a morphing technique, we linearly altered the category composition of images and measured 6.5-month-olds' attention to pairs of animal faces that either did or did not cross the categorical boundary, with the stimuli in each pair being equally dissimilar from one another across the two types of image pairs. Results indicated that infants dichotomize the continua between cats and dogs and between cows and otters, but only when the images are presented in their canonical, upright orientations. These findings demonstrate a propensity to dichotomize early in life that could have implications for social categorizations, such as race and gender.

Development of body emotion perception in infancy: From discrimination to recognition

Research suggests that infants progress from discrimination to recognition of emotions in faces during the first half year of life. It is unknown whether the perception of emotions from bodies develops in a similar manner. In the current study, when presented with happy and angry body videos and voices, 5-month-olds looked longer at the matching video when they were presented upright but not when they were inverted. In contrast, 3.5-month-olds failed to match even with upright videos. Thus, 5-month-olds but not 3.5-month-olds exhibited evidence of recognition of emotions from bodies by demonstrating intermodal matching. In a subsequent experiment, younger infants did discriminate between body emotion videos but failed to exhibit an inversion effect, suggesting that discrimination may be based on low-level stimulus features. These results document a developmental change from discrimination based on non-emotional information at 3.5 months to recognition of body emotions at 5 months. This pattern of development is similar to face emotion knowledge development and suggests that both the face and body emotion perception systems develop rapidly during the first half year of life.

Face Experience and the Attentional Bias for Fearful Expressions in 6- and 9-Month-Old Infants

Infants demonstrate an attentional bias toward fearful facial expressions that emerges in the first year of life. The current study investigated whether this attentional bias is influenced by experience with particular face types. Six-month-old (n = 33) and 9-month-old (n = 31) Caucasian infants' spontaneous preference for fearful facial expressions when expressed by own-race (Caucasian) or other-race (East Asian) faces was examined. Six-month-old infants showed a preference for fearful expressions when expressed by own-race faces, but not when expressed by other-race faces. Nine-month-old infants showed a preference for fearful expressions when expressed by both own-race faces and other-race faces. These results suggest that how infants deploy their attention to different emotional expressions is shaped by experience: Attentional biases might initially be restricted to faces with which infants have the most experience, and later be extended to faces with which they have less experience.