Stress Makes Us Try Hard for Pleasurable Rewards

To relieve stress many people use distractions. It can be relaxing with a book, movie, exercise or indulging in one's food or drinks cravings. A recent study shows that rewarding oneself with a drink or a sweet dessert does not serve the purpose as one is not likely to enjoy it as much as a person who indulges oneself just for pleasure.

"Most of us have experienced stress that increases our craving for rewarding experiences, such as eating a tasty bar of chocolate, and it can make us invest considerable effort in obtaining the object of our desire, such as running to a convenience store in the middle of the night," said lead author Eva Pool, MS, a doctoral student at the University of Geneva. "But while stress increases our desire to indulge in rewards, it does not necessarily increase the enjoyment we experience."

For the study,  a group of  36 students of whom 19 were chocolate lovers were tested on their stress levels. One group was asked to dip its  hands in cold water to induce stress. The other group did the test with lukewarm water. Their saliva was tested for cortisol  (stress hormone)levels before the test and 30 minutes into the test.

During the test the participants were asked to press a handgrip for a chance to smell chocolate when they saw a certain symbol on a screen in front of them .

The amount of effort put in the grip was tested and the students were questioned on how pleased they were at getting the odor of the chocolate

Stress prompted chocolate lovers in the  experiment to exert three times as much effort to smell chocolate than unstressed chocolate lovers, but both groups reported about the same level of enjoyment when they got a whiff of chocolate,  

"Stress plays a critical role in many psychological disorders and is one of the most important factors determining relapses in addiction, gambling and binge eating," said another author, Tobias Brosch, PhD, also of the University of Geneva. "Stress seems to flip a switch in our functioning: If a stressed person encounters an image or a sound associated with a pleasant object, this may drive them to invest an inordinate amount of effort to obtain it."

A previous research on rodents revealed that wanting and liking are governed by different   neurons in the brain that can be activated independently, which can be a possible explanation for the response in the humans, the authors said..

The study is published in APA's Journal of Experimental Psychology: Animal Learning and Cognition.