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. There are multiple lines of evidence that support this view. They are here briefly summarized along with some examples.
Experimental manipulations: Neuroimaging correlational studies cannot determine whether neural activity plays a causal role in the occurrence of mental processes and they cannot determine if the neural activity is either necessary or sufficient for such processes to occur. Identification of causation and necessary and sufficient conditions requires explicit experimental manipulation of that activity. If manipulation of brain activity changes consciousness, then a causal role for that brain activity can be inferred. Two of the most common types of manipulation experiments are loss-of-function and gain-of-function experiments. In a loss-of-function experiment, a part of the nervous system is diminished or removed in an attempt to determine if it is necessary for a certain process to occur, and in a gain-of-function experiment, an aspect of the nervous system is increased relative to normal. Manipulations of brain activity can be performed in several ways:
Symptoms of brain damage: Examining case studies and lesion studies are the only sources of knowledge regarding what happens to the mind when the brain is damaged. Various symptoms have been documented.
Mental development/brain development correlation: The brain grows and develops in an intricately orchestrated sequence of stages, and this development is correlated with the development of various mental capabilities. Impairments in the growth and development of the brain also result in various neurodevelopmental disorders.
Death
Death is the permanent cessation of all biological functions that sustain a living organism. Death was once defined as the cessation of heartbeat and of breathing, but the development of CPR and prompt defibrillation have rendered that definition inadequate because breathing and heartbeat can sometimes be restarted. Events that were causally linked to death in the past no longer kill in all circumstances; without a functioning heart or lungs, life can sometimes be sustained with a combination of life support devices, organ transplants and artificial pacemakers. Today, where 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.
Near-death experience (NDE)
A near-death experience is a personal experience associated with impending death, encompassing multiple possible sensations. Research from neuroscience considers 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.
