How does the brain support parent-child attachment?

Experiences early in life, when infants are highly dependent on their caregivers, can have profound effects on the brain. Research has shown that even young infants quickly learn the special relevance of their caregiver. For example, infants prefer their caregivers to strangers, learn to stay close to their caregivers, and are soothed by their caregivers (Ainsworth & Bell, 1970; Hofer, 1994). These processes are essential to forming a strong attachment between the parent and child. However, only recently has research shed light on the important role that the brain plays in parental bonding. Recent studies using functional magnetic resonance imaging (fMRI) have demonstrated that children distinguish between their caregivers and strangers even at the level of the brain. For example, one study found that children’s brains respond differently to pictures of their own mother, compared with pictures of a stranger (Tottenham et al., 2012). Specifically, children showed greater activation in the left amygdala, a region of the brain involved in emotional reactions, when viewing their mother (compared with viewing a stranger). While additional research is needed to fully understand this finding, one possibility is that caregivers preferentially recruit amygdala activation because of their salience during childhood. As evidenced by decades of research on parent-child relationships, caregivers are highly important in development. It may be that this unique relevance is reflected in children’s neural responses to their caregivers.

Research also suggests that parenting plays a profound role in shaping the development of the brain. To examine how early experiences with caregivers affect brain development, researchers have compared children raised by their families with children who were raised in orphanages when they were infants and who were later adopted into stable families. Children raised in orphanages experience a form of early-life stress, which includes atypical caregiving and reduced opportunities to form secure attachments with caregivers (Zeanah et al., 2003). This unique study design allows researchers to understand how the early, isolated period of stress affects later brain function and emotional behavior. When researchers showed these children pictures of their adoptive mothers and strangers, they did not see the same differential recruitment of amygdala activation observed in the typically reared children (Olsavsky et al., 2013). This finding highlights the long-term impact of early experiences on the brain, such that even children who have bonded to their adoptive mothers show different brain responses. If you are interested in more information on the role of early experiences on brain development, this paper provides a great review.

References

Ainsworth, M. D. S., & Bell, S. M. (1970). Attachment, Exploration, and Separation: Illustrated by the Behavior of One-Year-Olds in a Strange Situation. Child Development, 41(1), 49.

Hofer, M. A. (1994). Early relationships as regulators of infant physiology and behavior. Acta Pædiatrica, 83, 9–18.

Olsavsky, A. K., Telzer, E. H., Shapiro, M., Humphreys, K. L., Flannery, J., Goff, B., & Tottenham, N. (2013). Indiscriminate amygdala response to mothers and strangers after early maternal deprivation. Biological Psychiatry, 74(11), 853–860.

Tottenham, N., Shapiro, M., Telzer, E. H., & Humphreys, K. L. (2012). Amygdala response to mother. Developmental Science, 15(3), 307–319.

Zeanah, C.H., Nelson, C.A., Fox, N.A., Smyke, A.T., Marshall, P., Parker, S.W., Koga, S. (2003). Designing research to study the effects of institutionalization on brain and behavioral development: the Bucharest Early Intervention Project. Developmental Psychopathology, 15(4), 885-907.