After surviving a heart attack, some people recall being drawn towards a bright light - now the boffins may have a reason. They say the brain keeps working for up to 30sec after blood flow stops.
University of Michigan scientists conducted research on nine lab rats that were subjected to induced cardiac arrest. In the first 30sec after their hearts stopped, they all showed a surge of brain activity, seen in electroencephalograms (EEGs) that indicated highly aroused mental states. Prof.George Mashour: ''Many known electrical signatures of consciousness exceeded levels found in the waking state, suggesting the brain is capable of well-organised electrical activity during the early stage of clinical death.''
About 20% of people who survive cardiac arrest report having had visions during a period known to doctors as clinical death. "Reduction of oxygen or both oxygen and glucose during cardiac arrest can stimulate brain activity that's characteristic of conscious processing. It also provides the first scientific framework for the near-death experiences reported by many cardiac arrest survivors.''
|"OY! Who left the bloody |
fridge door open!"
But how much can a study on rats reveal about humans? After all, that may well have simply been the bright light inside a fridge full of cheese...