If you find your working relationships deteriorate as the day wears on, take a nap. In a study yet to be published, Matt Walker from the University of California, Berkeley, and colleagues showed people pictures of faces expressing different emotions, including fear, anger, sadness and happiness, and asked them to rate how emotional they thought these faces were. They did this at midday and again at 6 pm. Participants were significantly more sensitive to angry and fearful faces at the second session. However, this change did not happen if volunteers were allowed a 90-minute lunchtime nap during which they managed to achieve REM sleep. What's more, these people also became more receptive to happy faces. Walker concludes that REM sleep refreshes our civilising emotional reactions. "Sleep is essentially changing the magnetic north of your emotional compass, in a good way," he says. Full Article