Oxytocin Across the Transition to Fatherhood: Links with Prenatal Neural Activity During Theory of Mind and Postpartum Parenting Behavior

• In Event: Understanding and improving fathering in the prenatal and postnatal period

Abstract

Emerging evidence suggests changes in men's hormones at the prenatal and postpartum periods may indicate preparation for caregiving behavior. However, few studies have looked at fathers' oxytocin, a neuropeptide hormone associated with affiliative social behavior, across the transition to fatherhood. The current two-part study assesses associations between plasma oxytocin and fathers' caregiving indicators, both prenatally and at 6-months postpartum. Both studies use overlapping data, with participants being drawn from the University of Southern California Hormones Across the Transition to Childrearing study. In study 1, we focused on expectant fathers' neural activity during social cognition, which is thought to support fathers' sensitive caregiving behavior. We administered the Why-How Task, an fMRI task that elicits theory of mind processing to expectant fathers (n=39). Expectant fathers also visited the lab during their partner's pregnancy and provided a plasma sample for oxytocin assay. Our results from study 1 found that when rating "Why" an action was being performed vs. "How" the action was being performed, participants showed neural activity in regions theorized to support theory of mind, including medial prefrontal cortex, right temporoparietal junction, and posterior cingulate cortex. Fathers' prenatal oxytocin levels predicted greater activation to the Why condition in regions supporting theory of mind and embodied simulation (e.g., inferior parietal lobule). In study 2, fathers (n=45) took part in a free play interaction task at 6-months postpartum. We assessed paternal caregiving behaviors using a micro-coding coding scheme to analyze paternal touch. Our results from study 2 found that at 6-months postpartum, paternal unextracted oxytocin was positively associated with playful proprioceptive touch, functional proprioceptive touch, and gentle affectionate touch. Further, paternal unextracted oxytocin was negatively associated with the absence of father-to-infant touch. These findings held for both playful proprioceptive and absence of touch when using the more rigorous method of extraction to process oxytocin samples (i.e., extracted plasma oxytocin). In summary, these findings indicate the paternal oxytocin levels are related to neural activity during theory of mind processing prenatally, and with father-to-infant touch during postpartum play, suggesting that oxytocin may be related to paternal factors associated with caregiving across the transition to fatherhood. Future research will assess whether expectant fathers' prenatal plasma oxytocin levels and theory of mind processing directly predict postpartum fathering play behavior.

Authors

• Sofia Cardenas, University of Southern California
  Presenting Author

• Alyssa R Morris, University of Southern California
  Non-Presenting Author

• Chase H. Gilbertson, University of Southern California
  Non-Presenting Author

• Alexandra Turner
  Non-Presenting Author

• Darby E. Saxbe, University of Southern California
  Non-Presenting Author