Brain researchers for the first time claim to have found a method for improving the general problem-solving ability scientists call fluid intelligence, otherwise known as "smarts."

Fluid intelligence was previously thought to be genetically hard-wired, but the finding suggests that with about 25 minutes of rigorous mental training a day, healthy adults could improve their mental capacities.

The method, if commercialized, could be a boon to the growing, multimillion-dollar market for "brain fitness" software like Nintendo's Brain Age.

Fluid intelligence measures how people adapt to new situations and solve problems they've never seen before. Fluid intelligence differs from crystallized intelligence, which takes into account skills and knowledge that have been acquired -- like vocabulary, grammar and math.

In a limited trial, he and his team were able to make 34 test subjects significantly better at answering IQ test questions after training them on a completely separate memory task.