Darby Saxbe, a psychologist, directs the Center for the Changing Family and a research project to investigate how parents change biologically and neurobiologically in response to their babies at the USC Dornsife College of Letters, Arts, and Sciences. Saxbe, an associate professor, recently had a study published in the journal Cerebral Cortex in which he discovered evidence that men develop a type of “dad brain” after the birth of their child, similar to how mothers’ brains change in response to their newborns. She talked about why studying these changes in parents is important and what she plans to do next.
Why are you researching these changes in the brains of the parents? What do you hope to learn?
Parenting is extremely important for society and public health, but it is also poorly studied from a neurobiological standpoint. We hope that our research will help shape public policies such as paid family leave and other initiatives that help new parents.
What exactly is neuroplasticity, and what does it usually mean? What changes when one becomes a parent?
Neuroplasticity is still being studied, but there is evidence that the brain changes and grows when we learn a new skill, such as playing a musical instrument, or during developmental stages such as early childhood and adolescence. Being a parent requires changes to your lifestyle and biology, as well as new skills such as being able to empathise with a nonverbal infant, so it stands to reason — but has yet to be proven — that the brain would be especially plastic during the transition to parenthood.
According to the findings, you discovered changes in the default mode network. What exactly is this network, and what do these changes mean for new fathers? What does this mean for their romantic partners?
When the brain is at rest, the default mode network refers to the regions of the brain that “light up” (not doing a particularly cognitive task). These areas are thought to be involved in mentalizing about the thoughts and feelings of others. The fact that we discovered changes in that part of the brain in both fathers and mothers suggests that the social brain is being remodelled.
You notice that these changes are taking place in the cortex. What is the cortex in charge of, especially when it comes to parenting?
The cortex is the most recently evolved part of the brain, and it is more unique to humans. It is involved in attention, planning, and executive functioning. Subcortical regions (below the cortex) are the more primitive brain structures seen in animals, and they are involved in reward, threat, and salience detection. We see both subcortical and cortical changes in mothers, but only cortical changes in fathers. It’s too soon to draw conclusions from such a small sample, but it could point to more higher-order processing in fatherhood in particular.
