Relationships influence social and emotional functioning.
The research described above suggests how a child’s experiences early in life significantly affect brain development. Other research suggests that relationships are among the most important experiences that young children have, and that they have a particularly strong influence on social and emotional functioning. Although the connections between neurobiology and psychology between the physical and the emotional - are less well defined, we do know that one of the greatest predictors of social and emotional outcomes is a young child’s relationship with his or her primary caregiver (Sroufe, 1988). This relationship, known as an “attachment” relationship, develops when a child is between 6 and 18 months of age and reflects the sense of security the child feels in the presence of her caregiver (see Bowlby, 1969 and Ainsworth et, al, 1978). Because feeling of safety and security in the caregiver’s presence elicit particular biological responses to stress, they provide a foundation for healthy social and emotional development, and can positively affect the developing brain.
Specifically, children learn to regulate their emotional responses to events through caregiver behavior (Fox, 1998). If the attachment relationship is secure, a child learns to rely on the caregiver to help regulate her response to stressful situations and, over time, begins to self-regulate. If the attachment relationship in not secure due to inappropriate, inconsistent or ineffective behavior on the part of the caregiver, the child can experience prolonged episodes of unregulated stress and, in extreme cases, fail to develop self-regulating abilities such as the ability to calm oneself down after being startled, or the ability to put oneself to sleep. This prolonged exposure to stress hormones can even affect the synapses in the cortex, and can conceivably change the physical structure of the brain, if it occurs during the critical period of development for that region (Schore, 1996).
One group of parents whose children may be at risk for insecure attachment and prolonged exposure to stress is depressed mothers. Maternal depression occurs in mild form in approximately 40% of all mothers and in a moderate or severe form in approximately 10% of mothers during the immediate postpartum period (O’Hara, 1995). Although exacerbated by the physiological changes associated with childbirth, factors such as social support, family and spousal support, and employment play a critical role in a mother’s capacity to interact with her child. Mothers who suffer from clinical depression have difficulty responding appropriately to their infants, are often “out of sync” with their developing child, and frequently fail to respond adaptively to their infant’s emotional signals. Studies suggest that they are either more intrusive and controlling, or less attentive and engaged than nondepressed mothers (Dawson, Hessl and Frey, 1994), and observations of depressed mothers with their children can be quite dramatic: the infants smiles, the mother does not respond, and the child becomes agitated, looks away and appears distraught.
The effect of maternal depression on children’s brains has also been measured in the laboratory. Electroencephalographic (EEG) - or brain wave - recordings demonstrate that children of depressed mothers show more activity in the frontal brain region when expressing negative emotions than do children of non-depressed mothers (Dawson, Hessl and Frey, 1994 and Dawson et. al., 1997). This pattern of increased activity indicates an attempt by the child to regulate her negative reaction to an event, yet children of depressed mothers tend to be more irritable and display sadness and anger more frequently. Thus, the attempts of such children to control their negative emotions are often unsuccessful.
Infants of depressed mothers have also been found to have higher and more persistently elevated levels of cortisol, a hormone whose levels are associated directly with stress, than do infants of non-depressed mothers (Field et. al., and Dawson, Hessl and Fray, 1994). It is thought that this indicates that these infants perceive a lack of control over their environment and that, as a result, their ability to cope with stress is significantly impaired. Other studies suggest that persistently elevated levels of cortisol are associated with atrophy of the hippocampus, a region of the brain involved in memory and learning (Sapolsky, 1996). This would suggest that it is possible that maternal depression can have a permanent effect not only on the ability of the child to feel safe and in control, but even on the child’s ability to retain memories and therefore learn.