Is your mind buzzing 24/7? If so, you're in the grip of the overwork epidemic and enslaved by technology, says journalist India Sturgis. Mobile devices were meant to free us from the office, but technology has long ago killed the nine-to-five working day and left us mentally tethered to our desks, 24/7, instead.Professor Mark Cropley, a leading psychologist at the University of Surrey specialising in health and stress, outlines in his new book, The Off Switch , techniques to reduce the time it takes to unwind in the evening . Here are a few:At work: Establishing an "unwinding ritual" at the end of the working day trains your mind to slow down. "During the last half an hour, begin only jobs that are easy to complete, make a to-do list for the next day, clear your desk. With time, your mind and body will come to anticipate winding down," Cropley says.While you commute: "The shortest route to changing your thought patterns is to find a task that is the total opposite to your work and completely absorbs the mind," says Cropley. "For an accountant who looks at a screen for 10 hours a day, cycling home - a physical activity where you have to be aware of traffic around you - is ideal."At home: Get into the habit of switching off your phone after work or, at the very least, your e-mails. The daily bombardment of information from texts, e-mails and social media takes up neural resources and causes "decision fatigue", according to neuroscientist Daniel Levitin in his new book, The Organised Mind. ..