Lying down may make you smarter
A recent study by the Australian National University tested peoples' problem solving abilities while standing up and lying down. They found that people were slightly better at solving problems while in a horizontal position.
This difference in cognitive ability may come from the varied release of a neurotransmitter called noradrenaline, which is believed to interfere with creative thinking. When you are lying down, your body releases less noradrenaline.
So, if you need to do some serious thinking, lying down may slightly boost your performance.