Motherhood is definitely not just a boon, it’s a curse. It is rare that anybody is so straight forward about it, even assume so. But even less likely is anyone who gets so candid and blunt about motherhood without being reminded of it at every turn. In fact, for many women, motherhood is a constant struggle between self-imposed absolutes – a mother’s unalterable loyalty to her newborn; a mother’s unwavering resolve to breastfeed forever; a mother’s unrelenting refusal to accept that giving up the baby would mean giving up her freedom. Mothers, it turns out, have a knack for figuring out what counts as real life and what doesn’t. And for those of us who keep count, it seems that self-imposed limits almost always amount to nothing.

As we’ve come to know and experience motherhood, we’ve also come to appreciate just how much our brains change as we go through the process. We’ve come to recognize that the more we live with babies in our lives, the more our brains start to adapt to their environments. Mothers who breastfeed their babies longer and more insistently – even if it means their own sanity has to get on the line – demonstrate to themselves and to everyone else that they are still firmly committed to their child. They demonstrate to their brain memory that the bond they have with their babies is not one to be broken.

For some, this newfound commitment can lead to other kinds of brain adjustments, too. One study, for instance, found that women who were preoccupied with their babies’ well-being, spending time with them, stroking them, comforting them, and so on, exhibited lower levels of cortisol, a stress hormone. Women who were preoccupied with being mothers also exhibited higher levels of social memory, a skill that helps us remember our social surroundings. These results suggest that mothers who are preoccupied with the well-being of their babies may have greater psychological access to the parts of the brain that influence nurturing and caring.

But there’s something else going on here, as well. The same study found that mothers who felt like they were “unique” during pregnancy, experienced greater brain flexibility in terms of their maternal care giving. Specifically, the researchers found that their children benefited from having “mother-child memories” stored in the hippocampus, a brain region that helps us relate to our children in the present. What does this mean?

It means that the effects of sleep deprivation and cortisol on brain function aren’t fully represented by the results of studies on maternal care giving and brain development. The truth is that all these studies measure only the outcome of a single type of intervention, namely, the effect of cortisol on sleep deprivation. To really understand what’s going on, you need to consider two separate factors: first, the effect of cortisol on our cognition; and second, the effect of cortisol on our hormones. You see, the reason that we get sleepy during the night is that the levels of several hormones become unbalanced because we’re exposed to too much stress and strain at once. The good news is that this stress and strain dissipate with sleep, allowing our brains to take a break and regroup.

In the past, most scientists had only looked at the effects of cortisol on negative behaviors, like aggression and mood disorders. This new research highlights how important motherhood is for brain health, and the benefits that come from nurturing infants and taking care of new mothers. The results of the study show that mothers who feel like they are unique, that they have a unique role in their child’s development, and that they take care of themselves physically and emotionally are more likely to provide their children with emotional and physical care. Indeed, the results of this research demonstrate that nature neuroscience provides a significant step forward in the understanding of motherhood, and the benefits of motherhood.