Question: How do you test minds whilst there sleeping

Alex Reid answered on 13 Nov 2018: last edited 13 Nov 2018 6:22 pm

Hello! Thanks for the question. If we are measuring brain activity we use something called polysomnography (PSG). This comes from a combination of Greek and Latin words which roughly translate as ‘many channels’, ‘sleep’ and ‘to write’. We basically put a bunch of sensors on the head and face (the ‘many channels’) and this converts signals from these areas into something we can see, which is then ‘written’ into a computer. Your brain cells give off little electrical signals and we can measure these using PSG. We then score these records using a manual (a guidebook of rules) to give us our sleep measures (i.e. we make a good educated guess at what stage of sleep the brain is in). The other way we can test minds is by waking people up to ask them what they were dreaming about. This is far from perfect because waking people up disrupts the dream! However, it is also the best measure we have for this at the moment (until we invent better technology).