About the Continuity of Our Consciousness

Some people who have survived a life-threatening crisis report an extraordinary experience. Near-death experiences (NDE) occur with increasing frequency because of improved survival rates resulting from modern techniques of resuscitation. The content of NDE and the effects on patients seem similar worldwide, across all cultures and times. The subjective nature and absence of a frame of reference for this experience lead to individual, cultural, and religious factors determining the vocabulary used to describe and interpret the experience. NDE can be defined as the reported memory of the whole of impressions during a special state of consciousness, including a number of special elements such as out-of-body experience, pleasant feelings, seeing a tunnel, a light, deceased relatives, or a life review. Many circumstances are described during which NDE are reported, such as cardiac arrest (clinical death), shock after loss of blood, traumatic brain injury or intra-cerebral haemorrhage, near-drowning or asphyxia, but also in serious diseases not immediately life-threatening. Similar experiences to near-death ones can occur during the terminal phase of illness, and are called deathbed visions. Furthermore, identical experiences, so-called “fear-death” experiences, are mainly reported after situations in which death seemed unavoidable like serious traffic or mountaineering accidents. The NDE is transformational, causing profound changes of life-insight and loss of the fear of death. An NDE seems to be a relatively regularly occurring, and to many physicians an inexplicable phenomenon and hence an ignored result of survival in a critical medical situation. And should we also consider the possibility of conscious experience when someone in coma has been declared brain dead by physicians, and organ transplantation is about to be started? Recently several books were published in the Netherlands about what patients had experienced in their consciousness during coma following a severe traffic accident, following acute disseminated encephalomyelitis (ADEM), or following complications with cerebral hypertension after surgery for a brain tumour, this last patient being declared brain dead by his neurologist and neurosurgeon, but the family refused to give permission for organ donation. All these patients reported, after regaining consciousness, that they had experienced clear consciousness with memories, emotions, and perception out of and above their body during the period of their coma, also “seeing” nurses, physicians and family in and around the ICU. Does brain death really means death, or is it just the beginning of the process of dying that can last for hours to days, and what happens to consciousness during this period? Should we also consider the possibility that someone who is clinically dead during cardiac arrest can experience consciousness, and even whether there could still be consciousness after someone really has died, when his body is cold? How is consciousness related to the integrity of brain function? Is it possible to gain insight in this relationship? In my view the only possible empirical approach to evaluate theories about consciousness is research on NDE, because in studying the several universal elements that are reported during NDE, we get the opportunity to verify all the existing theories about consciousness that have been discussed until now. Consciousness presents temporal as well as everlasting experiences. Is there a start or an end to consciousness? In this paper I first will discuss some more general aspects of death, and after that I will describe more details from our prospective study on near-death experience in survivors of cardiac arrest in the Netherlands, which was published in the Lancet. I also want to comment on similar findings from two prospective studies in survivors of cardiac arrest from the USA 2 and from the United Kingdom. 3 Finally, I will discuss implications for consciousness studies, and how it could be possible to explain the continuity of our consciousness.