Interacting with other people through volunteering, work, and other social activities is also an important way to stimulate and challenge the brain, she adds.

CNN: Experts reveal best ways to save an aging brain

However, even if you didn't finish high school or have other factors you can't change, you can still challenge your brain to preserve mental function, Fiocco says.

CNN: Experts reveal best ways to save an aging brain

However, Dr Neil Stanley, of the University of Surrey, said sleep loss harmed spatial learning, although the brain could rise to the "spatial learning" challenge in the short-term it would struggle eventually.

BBC: Spatial memory works in a similar way in rats and humans

And because it could cost billions of dollars over several decades to build a comprehensive brain map, long-term funding could be another challenge.

WSJ: Obama Gives Details of Brain-Research Project

Colombian neuroscientist Ricardo Dolmetsch, on leave from Stanford, heads up another challenge: using stem cells to figure out what the brain is made of.

FORBES: Inside Paul Allen's Quest To Reverse Engineer The Brain

Several investigational compounds have been shown to be toxic to the liver, a challenge that highlights the difficulty in developing drugs for conditions that affect the brain.

WSJ: Fresh Target in Hunt for a Migraine Cure

The entertainment and challenge of games help us fight boredom, kill time, stimulate our brain capacity, socialize our networks as well as reach achievements and gain rewards.

FORBES: 7 Innovative Mobile Gaming Opportunities for Brands

The challenge for our workshop is remove from the students the common 'I am a left-brain person, I can't be creative!'

CNN: Learning to be creative