I was surprised to hear on the news that Sam Parnia has been awarded a big grant to find out whether the human spirit leaves the body at death – whether consciousness can survive when the brain is no longer working. He, and colleagues around the world, will place an image on a platform suspended from the ceiling of hospital wards and resuscitation areas, so that the image cannot be seen from below but could be seen if – during a near-death experience – the patient's consciousness left his body.

I was surprised, not that he has been awarded the grant, but that this made the news. But I assumed that this topic is of sufficient popular interest that, of all the thousands of research grants awarded, this one was worth reporting. Then I heard people saying it was a total waste of time and money. Surely we should be spending scarce research resources on improving patient care or developing new drugs shouldn't we? Well should we? Is this a good use of research money?

I long ago became fascinated with near-death experiences (NDE). In 1970, before the term was even invented, I had an extraordinary drug-induced experience (this was the time of hippy enthusiasm for old-fashioned mild cannabis). This life-changing experience included the tunnels, lights, out-of-body experience and meeting other beings that occur in the classic NDE. I was convinced that my spirit had left my body, and that is why I went on to become a parapsychologist, trying to prove this was true. I found it was not.

If there is any survival, I now think it's more likely to be through technological advances – you can hear me discussing this with musician Peter Gabriel, who is building the first "social networking site for the dead"!

I learned a lot about the experience though. In 1975, physician Raymond Moody coined the term NDE in his book Life After Life. Since then, research has shown that something like 10% of people who come close to death and survive report some kind of memory.

Most seem to rush down dark tunnels towards a bright light, many seem to fly out of their body to watch events as though from above, some go on into "other worlds" where they meet dead loved ones or angels or gods, and a very few reach a barrier from which they decide to return to life. Many are changed by their experiences, often becoming less fearful of death and less materialistic. All of this is well explained by what we know about how brain function changes as it approaches death, or even when in shock or severe stress. This "dying brain hypothesis" tells us a lot about what we can expect of our own deaths.

What could not be explained – if indeed it were true – is people actually seeing things that were happening at the time when they could not possibly have seen them with their physical eyes (or heard them described, or inferred them from what they already knew).

There are many claims of this kind, but in my long decades of research into out-of-body and near-death experiences I never met any convincing evidence that this is true. There is the famous case of the woman in Seattle who apparently saw a shoe on a high ledge and her social worker later found it there. This story, like so many others, relies on the testimony of just one person, in this case the social worker. The woman herself never told anyone else and is now dead, and there is no one else who reported seeing it. The testimony of one person, however sincere, is not sufficient to overturn much of science. And this is what would be entailed.

If human consciousness can really leave the body and operate without a brain then everything we know in neuroscience has to be questioned. If people could really gain paranormal knowledge then much of physics needs to be rewritten. This is what is at stake. Add to that the fact that most people in the population believe in some kind of life after death, and many desperately want it to be true, then you have a strong case for this research – even if the chances of success are vanishingly small.

If Parnia does the experiments properly, and his patients really can see those images, then I will change my mind about the paranormal. I don't think it's going to happen but I do think it's worth him making the attempt.