Getting out of one's comfort zone and learning a new skill can help improve brain activity, a new study has found.

Senior citizens are often advised to engage themselves in some activity such as solving crosswords to help maintain cognitive function. However, the latest study shows that these activities may not be doing much to keep the brain healthy.

Researchers at the University of Texas at Dallas and their colleagues found that mentally-challenging skills such as photography or quilting can keep the brain fit in old age.

"It seems it is not enough just to get out and do something-it is important to get out and do something that is unfamiliar and mentally challenging, and that provides broad stimulation mentally and socially," said psychological scientist and lead researcher Denise Park of the University of Texas at Dallas. "When you are inside your comfort zone you may be outside of the enhancement zone."

For the study, researchers invited 221 adults, ages 60 to 90 to participate in a particular activity for about 15 hours a week for three months.

Participants were assigned into three groups; first group got to learn a new skill such as digital photography or quilting; the second was given a familiar activity such as listening to music while the third group was sent on field trips and social events.

Researchers found that older adults engaged in skill-learning were showing improvements in memory when compared to people taking part in non-active or social activities.

"The findings suggest that engagement alone is not enough," Park said in a news release. "The three learning groups were pushed very hard to keep learning more and mastering more tasks and skills. Only the groups that were confronted with continuous and prolonged mental challenge improved."

The study is published in the journal Psychological Science.

Previous studies have shown that taking part in everyday activities too can act as a buffer in cognitive decline. People with high intellectual ability remain mentally healthy till very old age, says a study in American Psychological Association.