MONDAY, Feb. 4 (HealthDay News) -- When older people's mood improves, so does their brain power, new research suggests.

Being in a good mood appears to enhance decision-making skills and working memory among older adults, according to the study published in the current issue of the journal Cognition and Emotion.

The study authors suggested that even something as simple as a small bag of candy can help older people perform better on so-called "cognitive" -- or thinking skill -- tests.

"There has been lots of research showing that younger adults are more creative and cognitively flexible when they are in a good mood. But because of the [mental] declines that come with aging, we weren't sure that a good mood would be able to help older adults," study co-author Ellen Peters, professor of psychology at Ohio State University, said in a university news release.

"So these results are good news," she added. "There are ways for older adults to overcome some of the [mental] declines that come with aging"

In conducting the study, the researchers divided 46 adults ranging in age from 63 to 85 years into two equal groups. Those included in the first group were given a thank you note and two small bags of candy tied with a red ribbon to boost their mood when they arrived for the thinking skill tests. Those in the other group did not receive either a thank you note or candy.

During the experiment, the participants who received the candy used computers that had a sky-blue background screen with smiling suns on it. Meanwhile, those who didn't receive the candy used computers with neutral round images but no smiling faces on the sky-blue background.

The participants were given $3 in quarters and eight virtual decks of cards featuring a different pattern during the decision-making tasks. Four of the decks were considered "gain" decks. If participants chose a card from one of these decks, 75 percent of the time they won a quarter and 25 percent of the time they didn't win or lose. The remaining four decks were considered "loss" decks. If someone chose a card from a "loss" deck, they lost a quarter 75 percent of the time, the study authors explained.

The participants could also accept or reject the top card of the deck that was offered to them. Their goal was to win as much money as they could. The participants were not told what the card values were. Instead, they had to learn through trial and error. The researchers noted they were looking to see how quickly the participants would learn which decks won them money and which ones didn't.

The study revealed that the older adults whose spirits were lifted with a thank you note and candy performed much better at the decision-making test than the other participants.

"We used an experiential task because real life is experiential," Peters explained. "For example, you meet a new person and she is like one of these decks of cards. You don't know anything about her and you have to learn if she is someone you can trust. What this study suggests is that people who are in a good mood are going to learn faster and make better decisions."

The participants also performed a memory test. They listened as a group of random numbers and letters were read aloud to them and had to repeat the sequence back in numerical and alphabetical order. For instance, if they heard T9A3, they would have to repeat back 39AT. As the test progressed, the participants were challenged even more with larger sequences they had to memorize.

Again, the study showed that the participants who received the mood-boosting gift achieved higher scores.

"Working memory is important in decision making. If you're working your way through different options, how much you can remember of each option -- and can therefore compare and contrast in your head -- has a big impact on how well you can make a decision," Peters pointed out. "Given the current concern about [mental] declines in the aged, our findings are important for showing how simple methods to improve mood can help improve cognitive functioning and decision performance in older adults, just like they do in younger people."

The researchers noted that the participants' speed of processing and vocabulary were not affected by a better mood. And although the study found an association between improved mood and better thinking skills, it did not prove a cause-and-effect relationship.

More information

The U.S. National Institute of Neurological Disorders and Stroke has more about the brain and how it works.