Unless they are lying in bed preparing to die. In which case we could opt to hook them up to an EEG and record it, for the science. It would not be the least

Unless they are lying in bed preparing to die. In which case we could opt to hook them up to an EEG and record it, for the science. It would not be the least bit difficult to get any number of willing volunteers, it would not require some kind of accident. OP was wondering how it could be possible that nobody ever thought to do exactly that.