Dr. Ryuta Kawashima, represented polygonally in Nintendo DS juggernauts Brain Age and Brain Age 2, opts not to take his share of the profits from the games—instead directing them to support research at the university where he's employed.

"Not a single yen has gone in my pocket," Kawashima says, explaining he'd rather keep up his research rather than live a life of idle luxury. "Everyone in my family is mad at me but I tell them that if they want money, go out and earn it."

Kawashima's current work has him at Japan's only Nintendo-beating company Toyota, working on ways to help elderly drivers keep alert to avoid accidents.

'Brain training' Dr Kawashima has no time for games (AFP)