Postnatal mental health and mothers’ processing of infant emotion: an eye-tracking study

Characteristics of the time processing of adults' strongest sustained attentional bias toward neutral infant faces

Previous studies have shown that adults exhibit the strongest attentional bias toward neutral infant faces when viewing faces with different expressions at different attentional processing stages due to different stimulus presentation times. However, it is not clear how the characteristics of the temporal processing associated with the strongest effect change over time. Thus, we combined a free-viewing task with eye-tracking technology to measure adults' attentional bias toward infant and adult faces with happy, neutral, and sad expressions of the same face. The results of the analysis of the total time course indicated that the strongest effect occurred during the strategic processing stage. However, the results of the analysis of the split time course revealed that sad infant faces first elicited adults' attentional bias at 0 to 500 ms, whereas the strongest effect of attentional bias toward neutral infant faces was observed at 1000 to 3000 ms, peaking at 1500 to 2000 ms. In addition, women and men had no differences in their responses to different expressions. In summary, this study provides further evidence that adults' attentional bias toward infant faces across stages of attention processing is modulated by expressions. Specifically, during automatic processing adults' attentional bias was directed toward sad infant faces, followed by a shift to the processing of neutral infant faces during strategic processing, which ultimately resulted in the strongest effect. These findings highlight that this strongest effect is dynamic and associated with a specific time window in the strategic process.

The effect of emotional uncertainty on attentional bias toward neutral infant faces in adults

Recent studies have found that adults have stronger attentional bias toward neutral infant faces than emotional (positive or negative) infant faces. This phenomenon may derive from uncertainty over neutral expressions. To test this hypothesis, we recruited 176 participants to examine the relationship between their attentional bias toward neutral infant faces (with neutral adult faces as a comparison baseline) and their level of certainty in their appraisal of emotional valence through eye-tracking indices. The results showed that participants had a longer dwell time and higher fixation counts for infant faces than for adult faces and that a more uncertain appraisal of facial expressions positively predicted attentional bias toward neutral infant faces. Therefore, this study preliminarily demonstrates that emotional uncertainty heightens adults' attentional bias toward infant faces with neutral expressions.

Processing of infant emotion in mothers with mood disorders and implications for infant development

BACKGROUND

Atypical neurocognitive responses to emotional stimuli are core features of unipolar depression (UD) and bipolar disorder (BD). For mothers with these mood disorders, this may influence interactions with their infants and consequently infant development. The study aimed to investigate psychophysiological and cognitive responses to infant emotional stimuli, and their relation to mother-infant interaction and infant development, in mothers with BD or UD in full or partial remission.

METHODS

Four months after birth, mothers' cognitive responses to emotional infant stimuli were assessed with computerized tasks, while their facial expressions, galvanic skin responses (GSR), gazes, and fixations were recorded. Infant development and mother-infant interactions were also assessed.

RESULTS

We included 76 mothers: 27 with BD, 13 with UD, and 36 without known psychiatric disorders, and their infants. Mothers with BD and UD were in full or partial remission and showed blunted GSR and spent less time looking at infant stimuli (unadjusted p values < 0.03). Mothers with BD showed subtle positive neurocognitive biases (unadjusted p values<0.04) and mothers with UD showed negative biases (unadjusted p values < 0.02). Across all mothers, some measures of atypical infant emotion processing correlated with some measures of delays in infant development and suboptimal mother-infant interaction (unadjusted p values<0.04).

CONCLUSIONS

Mothers with mood disorders in full or partial remission showed atypical cognitive and psychophysiological response to emotional infant stimuli, which could be associated with mother-infant interactions and infant development. The study is explorative, hypothesis generating, and should be replicated in a larger sample. Investigation of the long-term implications of reduced maternal sensitivity is warranted.

Parental Sensitivity and Responsiveness as Mediators Between Postpartum Mental Health and Bonding in Mothers and Fathers

Background: There is a lack of studies that examine the complex relationship between parental mental health, parental sensitivity and responsiveness, and parent-infant bonding. This study aimed to test whether parental sensitivity and responsiveness were mediators between postpartum mental health (depression, anxiety, and stress) and parent-infant bonding in mothers and fathers. Method: Mothers (n = 427) and fathers (n = 170) of infants aged up to 1-year-old participated in an online study. The parents completed questionnaires on depression (Edinburgh Postnatal Depression Scale, EPDS), anxiety and stress (Depression, Anxiety, and Stress Scale, DASS-21). Parent-infant bonding was measured by Postpartum Bonding Questionnaire (PBQ) that has three components: Impaired bonding (PBQ1), Anxiety about care and parental distress (PBQ2), and Lack of enjoyment and affection with infant (PB3Q). Parental sensitivity was measured as the number of correct recognitions of infant facial expressions (City Infant Faces Database, CIFD). Responsiveness was measured as a self-report with two subscales of responsiveness and non-responsiveness (Maternal Infant Responsiveness Instrument, MIRI). Results: The path analysis showed that the model had a good fit to the data. Parental sex was a significant moderator, indicating different paths in mothers and fathers. In mothers, responsiveness and non-responsiveness were significant mediators between depression symptoms and three dimensions of bonding. In fathers, only non-responsiveness was a significant mediator between anxiety and PBQ3. Although recognizing infant facial expressions directly affected PBQ3 in mothers (but not in fathers), it was not a significant mediator between mental health and bonding. Conclusion: Higher levels of parental mental health problems (depression and anxiety) were associated with lower levels of parental responsiveness, which is, in turn, related to poor parent-infant bonding. Prevention and intervention programs should be offered for both mothers and fathers, focusing on postpartum mental health promotion and enhancing responsiveness in infant care.