Consciousness may continue even after death, scientists now believe.

Research into 'near-death' experiences has revealed that awareness and the mind may continue to exist after the brain has ceased to function and the body is clinically dead.

Scientists at the University of Southampton conducted a four-year study of more than 2,000 patients who had suffered cardiac arrests.

The research spanned cases at 15 hospitals in the UK, U.S. and Austria.

The findings revealed nearly 40 per cent of those who survived described some kind of 'awareness' during the time when they were clinically dead before their hearts were restarted.

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Out of body: In the study, conducted by scientists from the University of Southampton, one man even recollected leaving his body entirely and watching his resuscitation from the corner of the room. (File image)

Dr Sam Parnia, a former Southampton University research fellow now based at the State University of New York, who led the study, said: 'The evidence thus far suggests that in the first few minutes after death, consciousness is not annihilated.

'Whether it fades away afterwards, we do not know, but right after death, consciousness is not lost.'

The scientists heard one man recall leaving his body entirely, watching his resuscitation from the corner of the room.

The 57-year-old social worker from Southampton was 'dead' for three minutes yet managed to recount detailed actions of the nursing staff and the sound of the machines.

Dr Parnia said: 'We know the brain can't function when the heart has stopped beating.

'But in this case conscious awareness appears to have continued for up to three minutes into the period when the heart wasn't beating, even though the brain typically shuts down within 20-30 seconds after the heart has stopped.

'This is significant, since it has often been assumed that experiences in relation to death are likely hallucinations or illusions, occurring either before the heart stops or after the heart has been successfully restarted, but not an experience corresponding with ‘real’ events when the heart isn’t beating.

'Furthermore, the detailed recollections of visual awareness in this case were consistent with verified events.'

A total of 2,060 cardiac arrest patients were studied.

Of that number, 330 survived and 140 said that had been partly aware at the time of resuscitating.

Moment of peace: The bright light or golden flash image often used in Hollywood films was also described by some patients. Others experienced an unpleasant sensation of fears of drowning

Thirty-nine per cent of patients who survived cardiac arrest and were able to undergo interviews described a perception of awareness, but did not have any explicit memory of events.

'This suggests more people may have mental activity initially but then lose their memories after recovery, either due to the effects of brain injury or sedative drugs on memory recall,' said Dr Parnia.

Among the study participants who recalled awareness, and completed further interviews, 46 per cent experienced a wide range of mental recollections, that were not compatible with the commonly used term, near death experiences.

They included feelings of fear and persecution.

Lead researcher: Dr Sam Parnia said: 'The evidence thus far suggests that in the first few minutes after death, consciousness is not annihilated'

Only nine per cent had experiences commonly linked to a near death experiences, while two per cent showed full awareness or out of body experiences.

They explicitly recalled 'seeing' and 'hearing' events after their hearts had stopped.

In many of the cases, several similar trends emerged.

One in five described a feeling of peacefulness in the moment after death.

A third said time had either moved more quickly or slowed down. An out-of-body experience was felt by 13 per cent of those asked.

The bright light or golden flash image often used in Hollywood films was also described by some patients.

Others experienced a more unpleasant sensation of fears of drowning or being dragged through deep water.

Dr Parnia said that the number of people having experiences when close to death would be higher were it not for drugs and sedatives given to patients.

The study was launched in 2008 following a successful 18-month pilot phase at selected hospitals in the UK.

It allowed the research to be expanded to include other centres within the UK, mainland Europe and North America.

Dr Parnia added: 'Contrary to perception, death is not a specific moment but a potentially reversible process that occurs after any severe illness or accident causes the heart, lungs and brain to cease functioning.

'If attempts are made to reverse this process, it is referred to as 'cardiac arrest'; however, if these attempts do not succeed it is called 'death.

'In this study we wanted to go beyond the emotionally charged yet poorly defined term of near death experiences to explore objectively what happens when we die.

'While it was not possible to absolutely prove the reality or meaning of patients’ experiences and claims of awareness, (due to the very low incidence - two per cent - of explicit recall of visual awareness or so called out of body experiences), it was impossible to disclaim them either and more work is needed in this area.