How do expectant fathers respond to infant cry? Examining brain and behavioral responses and the moderating role of testosterone

Neural correlates of inhibitory control in the context of infant cry and paternal postpartum mental health

BACKGROUND

Inhibitory control, a form of self-regulation, may support sensitive parenting, but has been understudied in new fathers despite their pronounced risk for stress and mental health challenges.

METHODS

This study probed the neural correlates of inhibitory control and its associations to first-time fathers' postpartum mental health, focusing on depressive symptoms, state anxiety, and perceived stress. Six months after their child's birth, 38 fathers self-reported on their mood, anxiety, and stress, and performed a Go/No-Go fMRI task while listening to three sets of sounds (infant cry, pink noise, and silence).

RESULTS

Fathers' behavioral inhibition accuracy was consistent across the sound conditions, but their patterns of neural activation varied. Compared to the pink noise condition, fathers showed heightened engagement in prefrontal regulatory regions when self-regulating during the infant cry and silent conditions. When examining correct trials only, results in visual motor area and primary somatosensory cortex emerged only for infant cry and not for pink noise and silence. Moreover, fathers reporting higher levels of postpartum depression, state anxiety, and perceived stress showed greater activation in prefrontal regions when inhibiting during infant cry or silence.

CONCLUSION

This study is the first to underscore the complex interplay between the neural mechanisms related to inhibitory control and postpartum mental health and stress across varied auditory context, laying the groundwork for future research.

The effects of oxytocin and vasopressin administration on fathers' neural responses to infant crying: A randomized controlled within-subject study

In a randomized double-blind within-subject control study we investigated the effects of oxytocin and vasopressin administration on neural reactivity to infant cry sounds in 70 first-time fathers in the first year of fatherhood. Additionally, we examined whether effects of oxytocin and vasopressin administration on neural reactivity were moderated by fathers' early childhood experiences. Neural reactivity to infant cry sounds (versus control sounds) was measured using functional magnetic resonance imaging (fMRI). Furthermore, participants reported on their childhood experiences of parental harsh discipline and parental love withdrawal. Whole brain analyses revealed no significant effect of vasopressin or oxytocin administration on neural activation in response to infant cry sounds. Region of interest analyses showed decreased amygdala activation in both the oxytocin condition and the vasopressin condition as compared to placebo. We found no moderating effects of fathers' early childhood experiences. Our findings suggest that oxytocin administration may decrease feelings of anxiety or aversion to a crying infant. Whether decreased amygdala activation after vasopressin administration might be explained by contextual factors (e.g., absence of high levels of threat, unfamiliarity of the infant) or represents an affiliative response to infant distress warrants further investigation. Findings of the present study showed that oxytocin and vasopressin are important hormones implicated in neural models of infant cry perception in fatherhood.

Motivational increase of androgens and behavior by infant distress calls in highly responsive common marmoset fathers, Callithrix jacchus

Common marmoset fathers are highly involved in care of their infants. However, variability exists in their response to infant behavior even in paternally experienced fathers. Using infant distress cries as a motivation test, we investigated: 1. the differences in paternally experienced fathers' motivation to search for the infant vocalization stimuli; 2. the relationship between a father's motivation to search for the source of the infant cries and testosterone levels; and 3. if there is a rapid steroidogenesis pathway leading to increased testosterone and estradiol in the peripheral circulation. Only 44% of the paternally experienced fathers showed a high frequency of searching for the source of the infant distress cries. Through the use of multisteroid analysis, we found high responsive fathers had significantly higher levels of progesterone and testosterone in response to infant distress cries compared to a control stimulus with progesterone and androstenedione correlating with testosterone, while no differences were seen in low responders. The frequency to search for the infant stimuli was positively correlated with higher testosterone compared to control vocal levels. These results suggest that searching for the source of infant cries represents a motivation behavior for fathers that is activated by testosterone and reflects rapid circulating testosterone.

The Neural Basis of Human Fatherhood: A Unique Biocultural Perspective on Plasticity of Brain and Behavior

With the growing involvement of fathers in childrearing and the application of neuroscientific tools to research on parenting, there is a need to understand how a father's brain and neurohormonal systems accommodate the transition to parenthood and how such neurobiological changes impact children's mental health, sociality, and family functioning. In this paper, we present a theoretical model on the human father's brain and the neural adaptations that take place when fathers assume an involved role. The neurobiology of fatherhood shows great variability across individuals, societies, and cultures and is shaped to a great extent by bottom-up caregiving experiences and the amount of childrearing responsibilities. Mechanisms of mother-father coparental brain coordination and hormonal correlates of paternal behavior are detailed. Adaptations in the father's brain during pregnancy and across the postpartum year carry long-term implications for children's emotion regulation, stress management, and symptom formation. We propose a new conceptual model of HEALthy Father Brain that describes how a father's brain serves as a source of resilience in the context of family adversity and its capacity to "heal", protect, and foster social brain maturation and functionality in family members via paternal sensitivity, attunement, and support, which, in turn, promote child development and healthy family functioning. Father's brain provides a unique model on neural plasticity as sustained by committed acts of caregiving, thereby affording a novel perspective on the brain basis of human affiliation.

Recent Neuroscience Advances in Human Parenting

The transition to parenthood entails brain adaptations to the demands of caring for a newborn. This chapter reviews recent neuroscience findings on human parenting, focusing on neuroimaging studies. First, we describe the brain circuits underlying human maternal behavior, which comprise ancient subcortical circuits and more sophisticated cortical regions. Then, we present the short-term and long-term functional and structural brain adaptations that characterize the transition to motherhood, discuss the long-term effects of parenthood on the brain, and propose several underlying neural mechanisms. We also review neuroimaging findings in biological fathers and alloparents (such as other relatives or adoptive parents), who engage in parenting without directly experiencing pregnancy or childbirth. Finally, we describe perinatal mental illnesses and discuss the neural responses associated with such disorders. To date, studies indicate that parenthood is a period of enhanced brain plasticity within brain areas critical for cognitive and social processing and that both parenting experience and gestational-related factors can prime such plasticity.

Child maltreatment affects fathers’ response to infant crying, not mediated by cortisol or testosterone

Parents' ability to appropriately respond to infant crying is essential for parental care and has been found to relate to parents' own childhood experiences. Additionally, childhood experiences can affect endocrine factors, which may subsequently affect behavior. In the current study, preregistered on https://osf.io/hwgtu, we examined in expectant and new fathers (N = 152) associations between experiences of maltreatment in their own childhood, hair cortisol and testosterone concentrations and their ability to modulate handgrip force when exposed to infant crying. Cortisol and testosterone were quantified from the 1 cm of hair most proximal to the scalp using Liquid chromatography-tandem mass spectrometry. Participants were asked to squeeze a handgrip dynamometer at full and half strength while listening to infant cries and control sounds. Results indicated that fathers who experienced more childhood maltreatment used more excessive handgrip force during infant cry sounds. Hair cortisol and testosterone were not related to either experienced childhood maltreatment or handgrip strength modulation. These findings confirm that fathers’ early experiences of maltreatment reduce their ability to modulate their behavioral responses during infant cries, but suggest that hair cortisol and testosterone concentrations do not identify the underlying mechanism of this association.

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Childhood maltreatment relates to fathers' behavioural responses to infant crying.

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Childhood maltreatment is unrelated to fathers' hair cortisol and testosterone.

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Cortisol and testosterone are unrelated to behavioural responses to infant cries.

Theory of mind processing in expectant fathers: Associations with prenatal oxytocin and parental attunement

Social cognition may facilitate fathers' sensitive caregiving behavior. We administered the Why-How Task, an fMRI task that elicits theory of mind processing, to expectant fathers (n = 39) who also visited the laboratory during their partner's pregnancy and provided a plasma sample for oxytocin assay. Three months postpartum, fathers reported their beliefs about parenting. When rating "Why" an action was being performed versus "How" the action was being performed (Why > How contrast), participants showed activation in regions theorized to support theory of mind, including the dorsomedial prefrontal cortex and superior temporal sulcus. Fathers' prenatal oxytocin levels predicted greater signal change during the Why > How contrast in the inferior parietal lobule. Both prenatal oxytocin and attunement parenting beliefs were associated with Why > How activation in the dorsolateral prefrontal cortex, a theory of mind region implicated in emotion regulation. Posterior parahippocampal gyrus and dorsolateral prefrontal cortex activation during the Why > How contrast predicted fathers' attunement parenting beliefs. In conclusion, fathers' neural activation when engaging in a theory of mind task was associated with their prenatal oxytocin levels and their postpartum attunement parenting beliefs. Results suggest biological and cognitive components of fathering may track with the theory of mind processing.

Exploring the hormonal and neural correlates of paternal protective behavior to their infants

Infant protection is an important but largely neglected aspect of parental care. Available theory and research suggest that endocrine levels and neural responses might be biological correlates of protective behavior. However, no research to date examined associations between these neurobiological and behavioral aspects. This study, preregistered on https://osf.io/2acxd, explored the psychobiology of paternal protection in 77 new fathers by combining neural responses to infant-threatening situations, self-reported protective behavior, behavioral observations in a newly developed experimental set-up (Auditory Startling Task), and measurements of testosterone and vasopressin. fMRI analyses validated the role of several brain networks in the processing of infant-threatening situations and indicated replicable findings with the infant-threat paradigm. We found little overlap between observed and reported protective behavior. Robust associations between endocrine levels, neural responses, and paternal protective behavior were absent.

The Paternal Transition Entails Neuroanatomic Adaptations that are Associated with the Father's Brain Response to his Infant Cues

The transition into fatherhood is a life-changing event that requires substantial psychological adaptations. In families that include a father figure, sensitive paternal behavior has been shown to positively impact the infant’s development. Yet, studies exploring the neuroanatomic adaptations of men in their transition into fatherhood are scarce. The present study used surface-based methods to reanalyze a previously published prospective magnetic resonance imaging dataset comprised of 20 first-time fathers (preconception-to-postpartum) and 17 childless men. We tested if the transition into fatherhood entailed changes in cortical volume, thickness, and area and whether these changes were related to 2 indicators of paternal experience. Specifically, we tested if such changes were associated with (1) the baby’s age and/or (2) the fathers’ brain activity in response to pictures of their babies compared with an unknown baby. Results indicated that first-time fathers exhibited a significant reduction in cortical volume and thickness of the precuneus. Moreover, higher volume reduction and cortical thinning were associated with stronger brain responses to pictures of their own baby in parental brain regions. This is the first study showing preconception-to-postpartum neuroanatomical adaptations in first-time fathers associated with the father’s brain response to cues of his infant.