Brain research cited at online gaming site Happy Neuron has found that mental exercise helps stave off decline. Here's why: Mental workouts create new neural pathways that build up a mental savings account, a reserve to be drawn upon in time of need. Then, when you start losing neural connections (sad, but probably inevitable) you will still have enough left to function with.

You can't just practice the mental skills you're good at, according to Happy Neuron. You need to practice a broad range of skills -- memory, attention, language, executive functions (logic, problem solving, etc.) and spatial and visual skills. The site offers games in each category so that you can develop a balanced workout.

Of course, playing computer games won't do the trick by itself. Happy Neuron says that physical workouts, good nutrition and social interaction are needed, too.