I have definitely read many studies that say a bedroom should be for sleep and that's it - if you have your bedroom become a tv watching area then your mind associates the room with being awake and active, rather than being quiet and restful. So the studies say it's good to have a fun tv room where you watch tv and enjoy socializing with friends and such - but then a serene, quiet bedroom where the focus is on quiet, sleep, dark, rest.
It is amazing how your mind "responds" to a room when it's used to doing things there. So for example when you walk into a gym your mind automatically starts getting you ready to be active. When you walk into a spa, with its soothing colors and sounds, your mind automatically begins to relax. You want to use that to your advantage.
