Читать книгу Lifespan Development - Tara L. Kuther - Страница 157
Brain and Biological Influences on Development Pregnancy and the Maternal Brain
ОглавлениеPregnancy is associated with neurological changes especially in the areas of the brain responsible for social cognition.
John Bavosi/Science Source
The developing embryo and fetus receive a great deal of research attention, but what does pregnancy mean for mothers’ development? Women’s bodies undergo a radical transformation during pregnancy. For example, the hormone progesterone increases up to 15-fold and is accompanied by a flood of estrogen that is greater than the lifelong exposure prior to pregnancy. Research has shown that hormonal shifts are associated with brain changes during puberty as well as later in life. Do the hormonal changes with pregnancy influence women’s brain structure? Animal research suggests that pregnancy is accompanied by neurological changes, including changes in neural receptors, neuron generation, and gene expression, that are long-lasting (Kinsley & Amory-Meyer, 2011). It is likely that pregnancy is also associated with neural changes in humans, but there is little research to date (Hillerer, Jacobs, Fischer, & Aigner, 2014).
In a recent groundbreaking study, Elseine Hoekzema and colleagues (2017) conducted brain scans of women who were attempting to become pregnant for the first time as well as their partners. Women who became pregnant were scanned again after giving birth and at least 2 years later. The fathers and women who had not become pregnant were also assessed. The new mothers experienced reductions in the brain’s gray matter, signifying increased neural efficiency in regions of the brain involved in social cognition, specifically, theory of mind, which enables us to sense another person’s emotions and perspective (Schurz, Radua, Aichhorn, Richlan, & Perner, 2014). Theory of mind underlies a mother’s ability to interpret her infant’s mental states and is important for secure parent–infant attachment and for the development of the child’s own social cognitive functions (Meins, Fernyhough, Fradley, & Tuckey, 2001). The changes in gray matter volume predicted mothers’ attachment to their infants in the postpartum period, as indicated by mothers’ increased neural activity in response to viewing photos of their infant compared with other infants. Other research suggests that pregnancy is associated with the enhanced ability to recognize faces, especially those displaying emotions (Pearson, Lightman, & Evans, 2009). Gestational alterations in the brain structures that are implicated in social processes may offer an adaptive advantage to mothers by facilitating their ability to recognize the needs of their children and to promote mother–infant bonding.
Moreover, similar to findings with animals (Kinsley & Amory-Meyer, 2011), Hoekzema and colleagues observed that the neural changes that accompanied pregnancy were long lasting, persisting 2 years after birth. The pregnancy-related neurological changes were so marked and predictable that all of the women could be classified as having undergone pregnancy or not on the basis of the volume changes in gray matter. Notably, fathers did not show a change in gray matter volume, suggesting that the neural effects of pregnancy are biological in nature rather than associated with the contextual changes that occur with the transition to parenthood.