PHILADELPHIA (CBS) – Getting older and want to keep your mind sharp?

It seems that crossword puzzles and reading just won’t cut it.

According to a new study from the Association for Psychological Science and the University of Texas, only certain activities that are mentally demanding aid cognitive function in older adults.

The research, led by Denise Park of the University of Texas at Dallas, looked at 221 adults between the ages of 60 and 90 who were randomly assigned to engage in a particular activity for 15 hours a week over three months.

While some of the participants were assigned to listen to classical music, complete crosswords or partake in other “familiar” activities, others were told to learn an entirely new skill, such as digital photography, quilting or both.

To cover the social aspect, some study participants were also put together in a group that included social interactions like field trips and entertainment.

At the end of the three months, Park and her colleagues found that those who had learned a new skill showed greater memory improvement than those who had done the more familiar activities or those who were part of the social group.

“The findings suggest that engagement alone is not enough,” Park says. “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.”

“When you are inside your comfort zone you may be outside of the enhancement zone,” she adds.

Park and her colleagues plan to follow up with the study participants in one to five years to see if the effects on memory are long-lasting.

The full details of the research will be published in a forthcoming issue of the Association for Psychological Science’s journal, Psychological Science.