Deciding what to click on next when searching the internet may help stimulate the brain of middle-aged and older adults beyond the benefits of reading alone, researchers have found.

As the brain ages, cells shrink and their activity goes down, which can hinder performance. Activities that keep the brain active, such as completing crosswords and other puzzles, are thought to minimize the effect of aging on the brain.

"Internet searching engages complicated brain activity, which may help exercise and improve brain function," said the study's principal investigator, Dr. Gary Small, a professor of neuroscience and human behaviour at the University of California in Los Angeles.

In the study, 24 healthy volunteers between the ages of 55 and 76 had their brains scanned while they read books or searched the web.

Half were experienced internet users and the rest were not. Age, educational level and gender were similar between both groups.

The functional magnetic resonance imaging scanner measured the level of cerebral blood flow during the tasks, allowing researchers to track the intensity of cell responses in the brain.

Older brain 'continues to learn'

All participants showed significant brain activity while reading a book, which showed they were using areas in the temporal, parietal, occipital lobes and other areas that control language, reading, memory and visual ability.

But experienced internet users also showed a two-fold increase in brain activity, including areas in the frontal and temporal lobes and cingulate cortex that control decision-making and complex reasoning.

"A simple, everyday task like searching the web appears to enhance brain circuitry in older adults, demonstrating that our brains are sensitive and can continue to learn as we grow older," Small said.

As less experienced internet users spend more time online and learn how to search, they may show the same brain activation patterns as the more experienced group, he added.

Mental exercise, eating a balanced diet, getting physical exercise regularly and interacting with others frequently are other ways to avoid the effects of brain aging, neurologists say.