|
|
||||||
|
|
||||||
|
||||||
 |
|
|
||||||
|
|
||||||
|
||||||
|
|
|
|
|
Men, women differ in response to stress28 November, 2007 A study has shown that men and women differ in their neural responses to psychological stress. While men have a “fight-or-flight” response to stress, women are more likely to “tend-and-befriend,” according to a study conducted by researchers in the United States. The “fight-or-flight” response is associated with the main stress hormone system that produces cortisol in the human body, which is the hypothalamic-pituitary-adrenal (HPA) axis. In the study, published in the Social Cognitive and Affective Neuroscience, researchers at the University of Pennsylvania School of Medicine found that different parts of the brain activate with different spatial and temporal profiles for men and women when they are faced with stress linked to performance. Dr J J Wang, assistant professor or radiology and neurology and lead author of the study, said that, on account of evolution, males might have had to confront a situation or an incident causing stress either by overcoming or fleeing it. In contrast, women may have responded by nurturing offspring and affiliating with social groups that maximize the survival of the species. In the study, 32 healthy subjects – 16 females and 16 males – received functional magnetic resonance imaging scans (fMRI) before, during and after they were subjected, under pressure, to a challenging arithmetic task (serial subtraction of 13 from a 4-digit number). To increase the level of stress, the researchers frequently prompted participants for a faster performance and asked them to restart the task if they responded incorrectly. The participants were also asked to count backward without pressure. They measured heart rate, levels of cortisol (a stress hormone), subjects’ perceived stress levels throughout the experiments, and regional cerebral blood flow (CBF). The CBF provides a marker of regional brain function. In men, it was found that stress was associated with increased CBF in the right prefrontal cortex and a reduction of CBF in the left orbitofrontal cortex. In women, the limbic system – a part of the brain primarily involved in emotion – was activated when they were under stress. Though the brain activation in both men and women lasted beyond the task that gave them stress, the lasting response in the female brain was stronger. While neural response among the men was associated with higher levels of cortisol, women did not have as much association between brain activation to stress and cortisol changes. Dr J J Wang concluded: “Women have twice the rate of depression and anxiety disorders compared to men. Knowing that women respond to stress by increasing activity in brain regions involved with emotion, and that these changes last longer than in men, may help us begin to explain the gender differences in the incidence of mood disorders.”
|
|
|
|
|
|
