I will elaborate on this, but for now please take a peak at the Human Consciousness Project:
"In recent years, a number of scientific studies conducted by independent researchers have found that as many as 10-20 percent of individuals who undergo cardiac arrest report lucid, well-structured thought processes, reasoning, memories, and sometimes detailed recall of their cardiac arrest. What makes these experiences remarkable is that while studies of the brain during cardiac arrest have consistently that there is no brain activity during this period, these individuals have reported detailed perceptions that appear to indicate the presence of a high-level of consciousness in the absence of measurable brain activity.
These studies appear to suggest that the human mind and consciousness may in fact function at a time when the clinical criteria of death are fully present and the brain has ceased functioning. If these smaller studies can be replicated and verified through the definitive, large-scale studies of the Human Consciousness Project, they may not only revolutionize the medical care of critically ill patients and the scientific study of the mind and brain, but may also bear profound universal implications for our social understanding of death and the dying process."
