Near-death experiences (NDEs) in survivors of severe head injury with prolonged coma are markedly less common than in other near-death conditions such as cardiac arrest. In a study of 86 post-traumatic coma survivors, only 3 reported a clear NDE. Qualitative analysis of those 3 experiences revealed four master themes: unique light visions, intense feelings of astonishment, pleasure, and fear, a sense of helplessness, and a supernatural yet rational quality to the experience. The findings suggest that NDE incidence varies by cause of near-death state, and that head injury survivors who do have NDEs experience profound impacts on their beliefs and emotions.
The global workspace of consciousness, first proposed by Baars in 1982, describes how information becomes globally available in the brain, but its origin and mechanism remain poorly understood. One underexplored candidate is the brain's electromagnetic field. This review examines the theoretical framework and neuroimaging evidence for the global workspace model, then turns to electromagnetic field theories of consciousness. It highlights electromagnetic correlates derived from these theories that may underlie the global access phenomenon, suggesting that electromagnetic fields could play a key role in conscious awareness.
Consciousness remains a complex and fascinating phenomenon. While it has been pondered since antiquity, scientific investigation into it is relatively recent. Among the many theories about its nature and mechanisms, cognitive theories have gained wider acceptance. A prominent recent hypothesis is the 'conscious access hypothesis' based on the 'global workspace model of consciousness,' which highlights the global access of information in the cerebral cortex. This article reviews the theoretical foundations of the conscious access hypothesis and the experimental evidence supporting it.