A University of California Los Angeles team found searching the web stimulated centres in the brain that controlled decision-making and complex reasoning.
The researchers say this might even help to counteract the age-related physiological changes that cause the brain to slow down.
The study features in the American Journal of Geriatric Psychiatry.
As the brain ages, a number of changes occur, including shrinkage and reductions in cell activity, which can affect performance.
It has long been thought that activities which keep the brain active, such as crossword puzzles, may help minimise that impact - and the latest study suggests that surfing the web can be added to the list. More...