London: Even moderate levels of stress can impair self-control, a new study has revealed.
"Our findings provide an important step towards understanding the interactions between stress and self-control in the human brain, with the effects of stress operating through multiple neural pathways," said lead author Silvia Maier from University of Zurich, Switzerland.
"Self-control abilities are sensitive to perturbations at several points within this network, and optimal self-control requires a precise balance of input from multiple brain regions rather than a simple on/off switch," Maier added.
In the study, 29 participants underwent a treatment known to induce moderate stress in the laboratory before they were asked to choose between two food options.
An additional 22 participants did not undergo the treatment, which involved being observed and evaluated by the experimenter while immersing a hand in an ice water bath for three minutes, before choosing between the food options.
All of the participants who were selected for the study were making an effort to maintain a healthy lifestyle, so the study presented them with a conflict between eating a very tasty but unhealthy item and one that is healthy but less tasty.
The scientists found that when individuals chose between different food options after having experienced the stressful ice bath treatment, they were more likely to choose an unhealthy food.
The effects of stress were also visible in the brain. Stressed participants' brains exhibited altered patterns of connectivity between regions including the amygdala, striatum, and the dorsolateral and ventromedial prefrontal cortex, essentially reducing individuals' ability to exercise self-control over food choices.
"This is important because moderate stressors are more common than extreme events and will thus influence self-control choices more frequently and for a larger portion of the population," said senior author Todd Hare.
The study appeared in the journal Neuron.
