Functional connectivity of resting-state, working memory and inhibition networks in perceived stress

Abstract

Experimental imaging studies on the effects of acute stress have revealed functional changes in the amygdalae, hippocampi and medial frontal cortices. However, much less is known about the association between perceived stress and neurological function which may have implications for the development of stress related disorders. Participants completed a working-memory task and an inhibition task whilst undergoing a functional magnetic resonance imaging (fMRI) scan. Task related and resting-state fMRI data from 22 women and 24 men were analysed to investigate changes in task activations and functional connectivity associated with perceived stress over the past month. Analyses were stratified by gender due to gender differences in the stress response. Stress was associated with faster working memory response time in women, but not men. Stress was not associated with any differences in task activations in either gender. There were many significant associations between stress and connectivity: findings in women were consistent with increased emotional regulation; men exhibited decreases in connectivity between affective processing areas during the tasks and showed no relation between perceived stress and resting-state connectivity; very few of the within gender differences were significantly different between gender. Dysregulated connectivity between areas involved in the neural stress response and self-referential thoughts (e.g. the default mode network) suggests that perceived stress may have a subtle impact on cognitive processing and neural correlates.