The role of early experience in infant stress physiology.
Infant stress physiology provides a window into
the way the brain functions in relation to social and
cognitive development. Stress physiology affects how
we learn, and even how we learn to regulate the stress
system. The dialectical interplay between stress physiology
and learning partly reflects social and biological
feedback mechanisms that have evolved to help organisms
survive; these mechanisms require some training or
fine tuning during the course of early development.
In this talk, I present research that addresses three
questions that relate to the development of stress
physiology and its role in learning and memory in low-
and high-risk infants. The first is how the environment
affects the development of the stress system. Substantial
work, primarily with animals, indicates that early
experience permanently alters the development of the
stress system, a process that is fashionably referred
to as "programming." I provide some new evidence to
support this perspective in human infants. The second
question I consider is how infants learn to regulate
the stress system. Here I argue that infants learn
to regulate their stress in part by reacting to and
recovering from momentary failures in the parent-infant
relationship. I also consider the links between individual
differences in parenting style and infant stress regulation.
The role the stress system plays in learning and memory
is the focus of my final question. I build on developmental
and neurobiological theories of learning and memory
and present new evidence that the capacity to regulate
stress physiology plays an important role in contingency
learning and memory in infancy. I conclude with a discussion
of future directions.