Lallymac: That depends on the definition of clinically dead. If the patients were able to later recount their experiences then there was still life in their brains. Perhaps current technology is incapable of accurately measuring brain activity, and so those cases of clinical death were incorrectly classified.
There's also the possibility that the brain was active enough to perceive what was going on, but the seemingly conscious recall happened later. I.e., what the patient described as happening at the time of open-heart surgery was actually a memory that was formed later, once their brain was able to do so. And it was put together in the form of an OBE because that was how the brain coped with such a traumatic experience.
I don't know, do you have any references to that research? I'd be interested to see the method, and results.
Studies have been done whose researchers propose that certain parts of the physical brain are related to OBEs, and that stimulation of the brain can induce an OBE.
The wikipedia article about OBEs lists some studies.
I'll also point out that my limited understanding of how the brain works makes my explanation just as believable as the concept of mind and brain being separate. In other words in the face of limited information speculation is just that, speculation. OBEs, and any paranormal events, must have explanations which are more concrete than speculation before they're widely accepted. (according to the Amazon reviews, the book Dharma posted a link to doesn't present any evidence for what it says)
Uplift: Science has never been about absolute certainty. Scientists attempt to come up with a theory that most closely fits the available data while making as few assumptions as possible. That means that when key data is unavailable, or the data shows that certain elements of a theory are incomplete, using words which imply 100% certainty would be misleading.
Is it worse to admit one's uncertainty than to wrongly claim to be 100% correct?