Extreme Brain Workout - Vol. 2 (Harlequin Non Fiction) Marcel DanesiBuild your brain muscle! extreme brain workout is a series of puzzles designed to engage the core parts of your brain that are responsible for verbal ability, logical thinking and even your iq. Each group of puzzles progresses from simple to complex so that they are accessible and challenging for everyone, from the very beginner to the dedicated puzzle master. With each set of puzzles you'll also find information about the specific part of your brain