Stress reduces self-control

Heavy stress can reduce our decision-making ability. Now scientists are showing that even moderate stress is enough to lower our self-control. The study provides important information on how stress affects our brain in decision-making.

Image: Jürgen Fälchle - fotolia

In the study, 29 subjects underwent treatment in the lab that produced moderate levels of stress: they had to put one hand in ice water for three minutes. After this treatment, subjects in the MRI scanner selected between two dishes in a series of decisions. Another 22 subjects underwent a control treatment. When choosing the food, all study participants had the choice of eating something tasty, but unhealthy, or something that was healthy but less tasty.

It turned out that those with the stressful ice bath treatment were more likely to choose an unhealthy dish than those without ice bath treatment. The effects of stress could also be demonstrated in the brain using functional magnetic resonance imaging (FMRT).

Among the brain regions that are important for the exercise of self-control - such as the tonsil nucleus, the striatum, and the dorsolateral and ventromedial prefrontal cortex, which are important for decision-making - altered neural connection patterns were found in the stressed participants. However, the hormone cortisol, usually associated with stress, only played a role in some of these neuronal changes. (Pm)