Washington: Sad people seem to have a better memory advantage than their happier counterparts, an upside to being down in the dumps which, psychologists say, will shed light into how mood can affect the brain.
The findings, published in the journal Consciousness and Cognition, could also open the doors for better and effective treatments for depression, researchers said.
Past studies have found that unhappiness is often detrimental to a wide range of mental tasks, such as abstract thinking and remembering lists of words.
To learn more about how sadness might affect thinking, a team at the Anglia Ruskin University in England carried out experiments on college students involving face recognition.
The researchers put volunteers into happy, sad or neutral moods by having them listen to suitable music -- for instance, Mozart`s "Requiem" for sadness, the theme from "The A-Team" for happiness, and the soundtrack for the movie "The Hunt for Red October" for a neutral mood.
Participants were also asked to remember the happiest or saddest moments in their lives, or, for a neutral mood, their journey from home to the university.
In one experiment, 88 undergraduates were shown 32 faces with neutral expressions, then given a questionnaire as a brief distraction, then shown a sequence of 64 faces and asked to identify the ones they first saw.
The volunteers primed to feel sad turned out to be the most accurate, and the happy ones the least accurate.
"I was surprised," said study researcher Peter Hills, a cognitive psychologist at Anglia Ruskin University in England.
"Sad mood is usually associated with poorer performance in cognitive tasks."
In a similar experiment, 60 students viewed a series of faces with happy, sad or neutral expressions. Again, sad volunteers were the most accurate, regardless of the expressions on the faces they viewed.
Intriguingly, volunteers in happy or neutral moods were more accurate at recognising happy faces than sad ones, the researchers said.
"People prefer looking at happy faces -- isn`t a smiling face always more appealing than a sad one?" Hills said. "It may simply be that because we prefer looking at happy faces, we may pay more attention."
Elaborate thinking on the part of sad people could explain why they perform better at face recognition but worse at certain other tasks, the scientists said.
That advantage goes away when happy people are asked to actively think about the world around them.
"Although investigating sadness is useful in itself, the main focus is to try and understand how to prevent and treat depression," Hills said.
Perhaps understanding how sad people analyse faces could lead to a better understanding of how depression changes the way people view the world, pointing the way toward new avenues of therapy, he added.