She tested the animals response to danger by throwing a Frisbee over the maze and also by sounding a bird call to see how quickly the pups responded. High and low amounts of cortisol reduced the animals ability to learn how to respond to danger.
Among humans, what research that has been done on cortisol and learning has been inconclusive. Unlike animals, researchers cannot moderate cortisol levels in humans to study its impact. However, scholars are aware of situations in which cortisol levels change due to unusual interventions and events.
For instance, in order to help women at risk of pre-term birth deliver healthy babies, doctors sometimes treat them with synthetic glucocorticoids, which raise cortisol levels. The glucocorticoids facilitate fetal lung development.
We know almost nothing about the neurobiological implications of these treatments on cognitive development of children, she said. Animal studies have shown that these treatments can have negative effects on brain development, she said.
Additionally, little is known about the impact of low cortisol on learning among humans. Pregnant women who are exposed to stress, such as those tested after directly experiencing the collapse of the World Trade Center on 9/11, developed Post-Traumatic Stress Disorder and had significantly lower cortisol two years later, as did their babies.
The animal tests also help to understand the potential human impact of low cortisol on learning, she said.
|Contact: William Harms|
University of Chicago