Consciousness after death is a common theme in society and culture, and the belief in some form of life after death is a feature of many religions. However, scientific research has established that the physiological functioning of the brain, the cessation of which defines brain death, is closely connected to mental states.
Neuroscience is a large interdisciplinary field founded on the premise that all of behavior and all of the cognitive processes that constitute the mind have their origin in the structure and function of the nervous system, especially in the brain. According to this view, the mind can be regarded as a set of operations carried out by the brain.[1][2][3][4][5]
Many lines of evidence support this view, for example:
Death is the permanent end of all biological functions that sustain a living organism. It is no longer defined as the cessation of heartbeat (cardiac arrest) and breathing, as CPR and prompt defibrillation can sometimes restart both. In modern medicine, when a definition of the moment of death is required, doctors and coroners usually turn to "brain death" or "biological death" to define a person as being dead; brain death being defined as the complete and irreversible loss of brain function (including involuntary activity necessary to sustain life).[15][16][17][18]
A near-death experience (NDE) is a personal experience associated with impending death, encompassing multiple possible sensations. Some explanations from neuroscience hypothesize the NDE to be a hallucinatory state caused by various neurological factors such as cerebral anoxia, hypercarbia, abnormal activity in the temporal lobes and brain damage, though the exact nature of such experiences is not universally agreed upon.[19][20]