The Cerebrum
Main functions

'There is one mind common to all individual men [and women].'
Poet and essayist Ralph Waldo Emerson (1803-82)

'The lower levels of the brain are also depended on higher level activity in the cerebrum.'
SUNRISE

The cerebrum is a great mass of neuronal tissue making up a large portion of the human brain. It branches off from the brain stem just in front of the midbrain structures and bulges outwards into two large lobes called the cerebral hemispheres. There is also a mass of biological wires called the corpus callosum which seem to bypass the brain stem completely and make a direct link between the two lobes. These wires are deeply protected beneath and between the lobes and are positioned slightly forward from centre towards the frontal lobes.
The two lobes, or cerebral hemispheres, are so large and highly developed in humans that they literally wrap themselves around the upper parts of the brain stem and much of the midbrain sections as if to protect these apparently more sensitive and vital regions.
The surface of the cerebral hemispheres may appear smooth or heavily convoluted like valleys and hills, depending on the amount of brain usage. Upon closer examination, three crevasse-like subdivisions or fissures, called the longitudinal fissure, the lateral fissure and the central sulcus, can be seen. Inside the longitudinal fissure that divides the cerebrum into the two cerebral hemispheres is a mass of some three hundred million separate 'conducting wires' or nerve cell fibres that connect the two cerebral hemispheres together. This bundle of nerve fibres, known as the corpus callosum, shuttles information back and forth between the two hemispheres.
After many years of extensive research and experiments on the brain, there is general agreement by the scientists that the primary objective of the cerebrum is to store on a subconscious and more permanent level (compared to the hippocampus) the information and behaviours gathered and learnt over the lifetime of the living organism (the closest analogy would be the massive storage capabilities of the internal hard disk of a computer) and to use this more "unchangeable" information (unless deep meditation or hypnosis is applied) as an important source for our cognitive, ideational and imaginative functions as well as the development of our unique personality or personalised behaviour.
Although the cerebrum is capable of processing various types of information (including abstract symbolic information of language and pictures within the frontal cortex), its main purpose is to store and retrieve important patterns or symbols acquired over a lifetime of experience and knowledge, and to connect this information, by bundles of white-coloured nerve fibres called association areas, with itself and with various parts of the brain so as to help create, modify and refine our unique behaviours that make up our personality, including our thoughts and feelings, as well as to handle the great diversity of life experiences.
The storage area is located on the outer surface of the cerebrum and has a thickness of approximately one-eighth of an inch; it is called the cerebral cortex and is where our subconscious mind is generally said to reside (1).
Just below this dense, greyish-looking and highly dendrite-rich storage area lies the white-coloured association areas linking all our memories together and with the rest of human behaviour.

The removal of one or the other cerebral hemisphere has little consequence on the individualised behaviours, or personality traits, of a normal fully-grown adult (children, however, are a different matter all together) other than requiring the person to work harder on certain problem-solving activities. But evidence has shown that eventually the remaining hemisphere will take up much of the lost functions after a period of a few years. The main reason why the loss of one hemisphere does not affect personality is because the cerebrum is structured like some networks in society such as the Internet, with information spread out to different parts of the brain in an attempt to preserve and, if necessary, rebuild from this information, and so the chances of losing well-established personality traits following removal of one hemisphere or the other is therefore minimised.
However, the removal of both hemispheres of the brain will lead to a total loss in all individualised behaviours acquired over the lifetime of the individual. What behaviours remain are purely the basic and instinctive types needed for survival (such as activating, maintaining and regulating heart beat and so on). The result of such a major loss or damage to the cerebrum is a person described as a zombie or someone living in the vegetative state (2). An example of this can be seen among patients with Alzheimer's Disease, Parkinson's Disease etc where the cerebral hemispheres have undergone a certain level of degeneration.
Likewise people who have accidents resulting in damage to the cerebral hemispheres tend to experience this state.

It must be understood that no two human brains are exactly the same. Superficially, there are many similarities such as the two cerebral hemispheres and the various fissures that appear to divide the brain, but deep down, there are many elementary differences. The differences appear macroscopically as slight enlargements over certain parts of the brain and in its degree of convolution. Deeper down the differences are even more pronounced, with nerve cells creating and disassembling countless unique and dynamic patterns necessary for remembering or forgetting (for the purposes of acquiring more relevant patterns) various types of information.

NOTES

Scientific American 1992, p.56.

There are many similarities between this vegetative state and the moment just after death. In both situations, neither time nor place are observed or understood. Anyone who experiences this special state will discover they will not have a clue of who they were in the past, where they are now, where they are going next, or how much time has gone by.
Some Eastern mystics would describe this experience as a different form of freedom from what we are used to. It is a place where both pain and suffering are non-existent. The moment just after death may be described by some mystics as the blissful state of ultimate stability where you do not need to expend energy to think, do things like keeping warm or whatever else we think we need compared to our superficial world of constant change where we are doing many different things to adapt. Death, the vegetative state or whatever we wish to call this moment of true freedom, is just another means of balancing ourselves and the universe in order for this universe to exist and for all of us the opportunity to reexperience this universe and all it has to offer for all eternity.
To give you that brief experience of what it is like after we die, find a warm and sunny place in a park where there is absolutely no noise, no wind, neither too hot nor too cold, just warm. If necessary find a place where the sun can shine down on you to get that feeling of warmth.
Now sit down, relax, and pretend you cannot move any muscle in your body. This will simulate the moment when the motor control regions of your brain are non-existent.
Next, close your eyes so that you cannot see anything around you. The closing of your eyes will simulate the experience of the visual cortex of your brain shutting down. It will look dark, but somehow you can feel your body bathed in light of some sort. So you will not feel as if you are lonely or in some terrible place. There is darkness yet there is no darkness. This is one of the paradoxical things you should feel when you close your eyes in this natural setting.
Also the lack of noise, or very little noise, will hopefully simulate the experience of your auditory system disappearing into nothingness.
After a while, with all your senses ar ease, you will sense the feeling of complete relaxation, of quiet happiness and warmth, of not being aware of what's happening around you or what time it is. Even the sounds of nature in your environment will just mellow away to nothingness. This is perhaps the closest you will ever experience of what this special state we will all experience is like after we die and before whatever else happens to us after we reemerge from this blissful state (perhaps to return to this universe in a different place and time, who knows? This is the great mystery about this universe we have yet to understand).
## SPECIAL UPDATE ##
People may also go through a similar situation in near death experiences. For example, some people may describe the near-death experience in an objective manner as being in total blackness. As billionaire media magnate Mr Kerry Packer reportedly said after his near-death experience on the operating table when his heart stopped for eight minutes:
'There isn't a f**ing thing out there. Nothing but total blackness and oblivion.' (Cronin 2003, p.B7.)

Then there are other people who describe their near-death experiences as initially total blackness followed by observing some kind of a light at the end of a tunnel and being somehow drawn towards it.
Yet other people may get a feeling of being detached briefly from their bodies and looking down at everything around them during the experience.
And only a few may get images of what hell might be like such as seeing dead bodies being thrown into rubbish bins or some other gruesome image.
All these images are probably due to some electrical impulses in the brain still firing in certain parts of our recent memories and/or long-held beliefs (still intact and undamaged) leading to the creation of these unified images we see in our near-death experiences (and possibly revealing a little of our purpose in this universe or at least what we have learnt in the past after all this time) despite the heart stopping for a short while.
However, once the heart and the brain are permanently silenced and we experience true death where nothing can help us to return to our previous lives, all such images are likely to disappear like the clouds in a perfectly clear blue sky. And what you should be able to experience is this true blissful state where we are only able to get a glimpse of what it is like through meditation and in a quiet mind during a near-death experience.
## SPECIAL UPDATE ##
In some western religions, there is a belief that when good people die they will go to a place described as "heaven" and meet their creator and that is it. Anyone else who is not considered good is thought to end up in a place called hell.
In eastern mysticism, there is a belief that when people die they will return to this Universe (possibly as the same species) to continue the journey to some destination and possibly experience what they have left behind as their legacy in a previous life.
How do we reconcile these two differences?
Maybe western religions are trying to say that we will all eventually meet our creator, whether it is at the end of our lifetime, or in many lifetimes from now, and that eastern religion is only trying to say that to understand this ultimate goal we may need to return and experience this Universe many times until we have learned something very important.
And perhaps how many times we return to this universe and what experiences we go through (whether it feels like a heaven or hell) may depend on how often we fall into temptation and how we treat all of life in the Universe, which may either hasten the journey to reach our destination (ie. to meet our creator?), or for us to return to this universe to experience the consequences of our past actions as we continue our journey to understand the meaning and purpose of life and the Universe.
We can only speculate on what it could be.
Or m