Gould discovered evidence of adult neurogenesis in the hippocampus and olfactory bulb of rats, marmosets and macaque monkeys. In her early studies, she laid the groundwork for understanding the relationship between stress and adult neurogenesis. Specifically, she and Dr. Heather A. Cameron reported on adrenal steroid control of adult neurogenesis in rat dentate gyrus. Additionally, her work has provided evidence of neurogenesis in the adult primate neocortex. Gould and the researchers reported new neurons in adult marmoset monkeys are added to three neocortical association areas important in cognitive function: the prefrontal, inferior temporal and posterior parietal cortex. The new neurons appeared to originate in the subventricular zone, where stem cells giving rise to other cell types are located. They then migrate through the white matter to the neocortex, extending axons. Continual addition of neurons in adulthood apparently contributes to association neocortex functions.