I did a paper in grad school about digital v. analog resources (e.g. paper) and learned the brain actually processes information from a screen differently than from a physical page. The eyes track differently, too. So if you get stuck while staring at a screen, a switch to a journal could get the brain moving again. Also, from a teaching/learning standpoint, the journal engages more of the senses and thus gives information more paths to travel to your brain--your hand holding the pencil, your nose smelling the paper, etc.