Brain training games have kept human minds sharp for centuries and they can also keep dogs switched on in old age, research shows.<br /><br />Like us, dogs' brains can be kept sharper for longer if they play specially designed computer games.<br /><br />Dog owners often become more forgiving of their pets' disobedience and stubbornness as they grow old, which can actually speed mental slowdown.<br /><br />But a study revealed challenging pooches with specially developed touch-screen games, including a 'dog sudoku', exercises their minds and slows brain ageing.