The finding came from a study at the University of Georgia, led by professor of psychology Leonard Martin and Matthew Sanders, a doctoral candidate also in the UGA Franklin College of Arts and Sciences, and was published in Psychological Science.
Fifty-one students were involved in the study and were asked to perform two assignments so that the team could test self-control.
In the first assignment, the subjects were asked to cross out the Es on a page from a statistics book, which has been known to diminish self-control.
In the second task, they were asked to identify the color of different words, which actually spell out the names of other colors, that were flashed on a monitor. This is called the Stroop test, in which the aim is to turn off a person's inclination to read the word instead of see the color.
The participants were divided into two groups - half rinsed their mouths with lemonade sweetened with sugar while they completed the Stroop test and the other group with Splenda-sweetened lemonade.
According to the results, students who rinsed with sugar responded to the color rather than the word significantly faster than those in the artificial sweetener group.
"Researchers used to think you had to drink the glucose and get it into your body to give you the energy to (have) self control. After this trial, it seems that glucose stimulates the simple carbohydrate sensors on the tongue. This, in turn, signals the motivational centers of the brain where our self-related goals are represented. These signals tell your body to pay attention."
The Stroop test was completed in about three to five minutes. A measure of self-control was seen in the results, Martin said, but a glucose mouthwash might not be sufficient to fix certain self-control hurdles such as quitting smoking or losing weight.
"The research is not clear yet on the effects of swishing with glucose on long-term self-control," Martin said. "So, if you are trying to quit smoking, a swish of lemonade may not be the total cure, but it certainly could help you in the short run."
The ambition is seen in the form of self-values, or emotive investment, the authors revealed.
"It is the self-investment," Martin said. "It doesn't just crank up your energy, but it cranks up your personal investment in what you are doing. Clicking into the things that are important to you makes those self-related goals salient." According to the scientists, emotive enhancement is what results from the glucose, which causes people to be more aware of their desires and try harder at evoking the non-dominant response.
"The glucose seems to be good at getting you to stop an automatic response such as reading the words in the Stroop task and to substitute the second harder one in its place such as saying the color the word is printed in," he said. "It can enhance emotive investment and self-relevant goals."
Prior research on self-control demonstrated a considerable decrease in performance for the Stroop test. Studies have suggested, Martin said, that this is because the first task is too difficult that you just don't have the energy to complete the second assignment.
We are saying when people engage in self-control, they ignore important aspects of their goals and feelings. If you have to stay late at work, for example, but you really want to be going home, you have to ignore your desire to go home. Doing so will help you stay late at work, but it may also put you out of touch with what you personally want and feel on later tasks. Swishing glucose can focus you back on those goals and feelings and this, in turn, can help you perform better on the second task. In short, we believe self-control goes away because people send away, not because they don't have energy. People turn it off on purpose."
The study's main goal was to identify the impact of swishing glucose on a psychological level. "We think it makes your self-related goals come to mind," Martin said.
The team is conducting more research to examine how people evoke emotive responses and how they interpret them.
Written by Sarah Glynn