Playing the classic puzzle game Tetris can boost your brain power, according to a new study. The three-month study, by the Mind Research Network, found adolescent girls who played Tetris not only displayed greater brain efficiency, but developed a thicker brain cortex, a sign of increased grey matter. Clinical neuropsychologist Dr Rex Jung said one of the most surprising findings of brain research in the past five years was that juggling game play increased grey matter in the motor areas of the brain. Study co-author Dr Richard Haier said Tetris had proved useful for brain researchers. "Tetris for the brain...