Religious Experience, NDE & The Brain
As mentioned in the earlier article, recent discoveries and the consequent improvements in medical care have revealed a maze of ethical issues which were formerly reserved for philosophical debate. Many now feel that the progress of science, although undoubtedly bringing benefits, has itself begun to threaten the sanctity of human life. Some scientists believe that ultimately everything, including issues that may be considered theological or philosophical, are amenable to the objective study of science.
In this context, how does the brain work and what does this tell us about our spiritual or religious experiences?
Like many other complex structures in the body, the brain is made up of a number of different parts, all connected in a way which allow it to perform its overall function.
The brain has two mirror-image halves, called the cerebral hemispheres, which, according to one eminent brain scientist, Professor Ramachandran, resembles a 'walnut sitting on top of a stalk, called the brain stem'. Each half of the mirror-imaged brain, or hemisphere, is divided into four areas that have different functions: the frontal, parietal, occipital and temporal lobes, which make up the surface structure of the brain called the cortex. There are also some areas that lie between the stalk and the cortex, including the areas responsible for the initiation and modulation of movement, temperature regulation and goal-directed behaviour such as eating, drinking and reproduction, together with the expression of emotions. These sections are also connected via tracts of nerves to the rest of the brain and the rest of the body.
The cerebral cortex, the structure on the surface of the brain is involved with higher brain function, including thought processes, listening, seeing, counting, drawing, recalling memories and moving particular muscles such as the arms and legs. The frontal areas are concerned with some very mysterious aspects of the human mind and human behaviour such as moral sense, wisdom, ambition and other activities of the mind about which we know very little. Damage to the frontal section of this part of the brain typically causes changes in personality and problems with the sensation of touch as well as with speaking, whereas damage a little further behind, in the parietal area, can cause problems with speech as well as the use of arms and legs. These areas are also concerned with creating a three-dimensional representation of the spatial layout of the external world, and of our own body within that three-dimensional representation.
Further back is the occipital area, which is involved with vision and damage to which can result in blindness, and to the side is the temporal region, which is involved with certain aspects of memory, hearing, emotions and visual perception.
Underneath the cortex or main surface structure of the brain, which mediates all higher brain functions, is the stem, otherwise known as the brain stem, which maintains all of life's vital processes, including heartbeat and breathing, as well as important reflexes such as the pupillary reflex, which controls the size of our pupils in response to light, and the gag reflex, which prevents food and other swallowed objects going down the windpipe. The other important function of the brain stem is maintaining wakefulness. So damage to the brain stem may lead to unconsciousness, loss of vital reflexes and eventually death.
Due to its position the brain stem is also very much like a highway junction through which all the connections between the body and brain pass. For example, all the nerves carrying sensations from the rest of the body converge in the spinal cord before travelling up through the brain stem and then branching off to the different sections of the brain, including the cerebral cortex, where the higher functions are carried out. Messages are then relayed back to the body from the cerebral cortex via the brain stem.
Behind and just above the brain stem lies the area of the brain that is responsible for the regulation and co-ordination of our movements such as walking and running. This is the third main structure in the brain and is called the cerebellum.
The different areas of the brain are in a constant state of communication through electricity carried by long tracts of nerves. If any area of the brain becomes damaged, this will affect the normal patterns of electricity, which is why an EEG monitor, which measures electricity, can be used to diagnose brain diseases.
The source of the electricity flowing across the brain are the specialized brain cells called neurones. The brain is thought to be made up of 100 billion of these neurones and they form the basic structure and functional units of the nervous system. Each neurone is connected to other brain cells through 1,000 to 10,000 contacts called synapses. It is here that exchange of information takes place between brain cells. This is incredible - with around 100 billion cells, each with 1,000 to 10,000 connections to other cells, the total number of permutations and combinations of brain connections and hence activity is almost infinite! All the different brain states, including all our emotions, such as love, hate and anger, as well as our thoughts, ambitions and even religious sentiments, are mediated by these connections or synapses, which have themselves been shown to vary and become more complex if a certain area of the brain is being used and developed. In fact it is thought that no two people, even twins, will have exactly the same brain connections or wiring, since these synapses or connections develop and change constantly according to different stimulation of the brain areas during our lifetimes. This is because as we grow, learn and generate new experiences, the connections in our brains become more extensive. These ultimately depend, then, on the richness of experiences.
The neurones themselves are constantly generating electricity through the passage of positively and negatively charged chemical elements, such as sodium, in and out of the cells via special gates on the surface of the cells. The electricity then flows along the entire length of a cell until it reaches another brain cell. At that point it causes a special chemical, called a neurotransmitter, to be released from the first cell onto the next cell, where it causes gates on the surface of the second cell to open, which again generates the electricity along the length of that cell by allowing positive and negative elements to go in and out of the cell. Sometimes when these neurotransmitters are released, they have the effect of stopping the electricity from going along any further at the next junction and at other times they may cause further action at the next nerve junction. This is how they stop a signal or send it on.
Like almost all other cells in the body, neurones also produce proteins and protein-derived chemicals in response to a special code. This code is essentially in the form of genes that are in the nucleus, or control room, of each cell. The chemical products sometimes have the function of maintaining the structure of the cells themselves and at other times may be released from the cells to have an effect on neighboring cells.
As well as neurones there are also other cells, called glial cells, in the brain which do not produce electricity but just act as support for the electricity-producing neurones. Their name comes from the Greek for 'glue', because when looked at though a microscope some of these cells appear to be attached to the neurones like glue. They are like scaffolding maintaining the structure of the brain while the wire-like neurones transmit the messages.
The brain is thus a highly complex and well-organized mesh of electrical wires that form a network of electrical superhighways conducting information to and from the most distant parts of the body. So in the brain it is not an individual cell that performs a particular function, rather a large group of cells all connected together, otherwise known as a 'neural network'. It is therefore the overall activity of multiple areas of the brain that is involved with all the functions of the brain, including conscious experiences such as thoughts, vision and hearing.
The difficulty for science is determining how from the activity of these cells, do thoughts arise? Today there is no plausible scientific theory to explain how this can arise and therefore the arguments largely mirror philosophical views.