A study detected hidden consciousness in one out of seven unresponsive brain injury patients using widely-available hospital technology. (Credit: Chairoij/Shutterstock)

There are some things that life never prepares you for — like the dreaded phone call that a loved one is in a coma, and you’re responsible for making their end-of-life decisions if they don’t wake up. These decisions are further complicated by the fact that there’s no true test for consciousness. And, unfortunately, it’s diff