Question: What happens when someone is brain dead?

Sarah Finnegan answered on 22 Sep 2017:

Hi Logan, I’m going to retype my answer to someone else. Hope you don’t mind! I think its probably my best answer:
Well i’m not 100% sure but I think if we say someone is brain dead it means that we can’t detect any brain signal using equipment like EEG and there are no responses to tests like shining a bright light into the persons eyes. Tests like these are definitely not foolproof though which makes decisions like whether the person should remain on life support very difficult! Probably the person isn’t aware of anything. However! MRI scans are starting to be used to help people who are in a coma. Because different areas of the brain are activated depending on what you think of, you can ask someone in the scanner to think of playing tennis and then to think of a persons face that they know. If the person in the coma is conscious then we will see the different brain areas become active!