Regularly solving puzzles and quizzes are useful in maintaining a sharp mind, according to a new study.
It is often believed that brain games do little more than allow the participant to develop strategies for improving performance on that particular task. The improvement does not typically extend beyond the game itself.
But the latest study reports that a group of college students improved their performance on a pattern-recognition test - a commonly used intelligence test - after training their working memory.
In the study, Susanne Jaeggi and Martin Buschkuehl, both now at the University of Michigan in Ann Arbor, and their colleagues recruited 70 participants from the University of Bern in Switzerland, and trained them on a rigorous memory test.
The test consisted of a string of events: every three seconds, a small white box would appear on the screen in varying locations while at the same time a letter of the alphabet was read aloud.
In the research, the volunteers were asked to indicate when the current box-letter combination matched what they saw and heard some number of trials back.
The number of trials that the test subjects had to remember depended on how well they did on the test - someone with a good memory might be asked to recall what they saw six trials previously, for example.
Participants practised this test for 25 minutes a day for 8 to 19 days. After that, they were given a pattern-recognition test to assay 'fluid intelligence' - the ability to solve problems, use abstract reasoning, and adapt to new situations.
A typical intelligence test, often called an IQ test, will measure both fluid intelligence and 'crystalline' intelligence - a measure of learned abilities such as vocabulary or specific skills.
The researchers found that those who had trained on the working memory test scored on average a little more than one point better than the control group in a test of 29 questions. The effect was larger among those who trained for longer.
It's unclear, however, whether this improved 'intelligence' would make a difference to a person's life.
"The impact of fluid intelligence on adult day-to-day life is not clear. Based on 100 years of research on human intelligence, fluid intelligence is not closely related to professional success," Nature quoted Phillip Ackerman, a experimental psychologist at the Georgia Institute of Technology in Atlanta, as saying.
The study is published in Proceedings of the National Academy of Sciences.