Brain vs. Mind
Mind vs. Soul
Brain vs. Mind
Mind results from the organized connections of neurons within the brain, connected both to the environment and to mechanisms for changing the environment (muscles). So is it true to say the mind is nothing but the brain? Scientists who want to find better ways to explain the connection between the brain and mind often take the view that all that´s necessary to understand the mind is in the brain, because that keeps them looking for materially-based explanations, which is how cognitive science progresses. However, at present no one can say for sure how a single "thought" happens, and probably many aspects of cognition will never be explained through a scientific approach alone. Explanations of our thoughts are a subset of our thoughts, not the other way around. Theories should be tools to help us understand and better ourselves, not weapons for those who want to degrade our appreciation of ourselves and other human beings by reducing us to organic machines.
Matter, Energy, and Life
All material things (matter) are made of tiny pieces called atoms, which can join together in different combinations to make structures called molecules, which, in the case of living things, can be very large and complex. Molecules are connected together (whether loosely in gases and liquids, or more closely and with less movement between them, as in solids) to make what we call objects.
Whether viewed as atoms, molecules, or objects, all particles (pieces of matter) can have energy. Energy is the potential to change other matter in the following ways:
Energy, like matter, does not disappear, it only changes its type. But, since the beginning of time, energy has been changing all the matter in the universe to make it less and less complicated. In other words, hills are flattened and valleys filled in, hot places cooled and cool places warmed, "information," or the potential to be differentiated, is decreased.
This is the direction which the use of energy causes matter to take, but small pockets, which we call life, take in large amounts of energy from the nuclear self-destruction of the sun (or from other living things) to create and preserve order and information. For something to live it must have the right structures and chemicals to take in energy and use it to grow, it must have energy to take in, and it must be able to pass on its information for growing and chemical systems for using this information to make a new life which is almost exactly like itself, but just a little different.
Human Life and the Human Brain
The more complicated a living thing, the more needs it has, and the more it needs to be able to (and is able to) adapt to different environments. We human beings, the most complicated living things of all, can not only adapt to a huge variety of natural environments, we can imagine new environments and our roles in them. We can thoroughly manipulate and change our environments, and then adapt to these changes as well.
The brain is the part of the human body which:
The brain works to meet the basic human goals of pleasant survival and later the creation and sustaining of offspring. Cognitive science adds another basic goal, that of an interesting life which one is able to make sense of and consider, meaningful. This last goal of course ultimately helps to meet the first two.
Cells and Nerve Cells
All living things are made of cells, from bacteria which are a single cell, to people which are made of trillions (millions of millions) of cells, working together. A cell is a packet of biomolecules (molecules made in living systems) interacting in a water solution, some of them connected to form distinct cellular structures. A cell is separated from its environment by a membrane which lets only certain things in and out at certain times.
Animal cells use fuel molecules made by plants from the radiating energy of the sun (or by animals which eat plants or animals that eat plants, etc.) to build and change molecules and structures within themselves. This is done by "translating" the information contained in a cell´s DNA in it´s nucleus (membraned center dot) into biomolecules. Much of this information may be turned off (be unavailable for translation) for any given cell, because the information is for all types of cells in the body and for any one type of cell information specific to other types is irrelevant. Also, at any one time most of the information which could be relevant to a certain cell is turned off until it is needed. For example, the information for the molecules necessary to digest a sugar are turned off until that sugar is present and chemically turns the information on.
The DNA information of a cell, along with all it´s other parts, replicate and divide, so that a mother cell forms two identical daughters. This is cellular reproduction. The other kind, sexual reproduction, occurs only in living things whose cells have two different sets of information for each biological function. One cell each from mother and father, each containing one randomly mixed set of information, combine to make a new creature, similar to mother and father but different from both.
The following types of cells make our bodies:
Our circulatory system is made of hundreds of thousands of vessels which contain blood cells floating in a mix of water and other chemicals. The cells and fluid are pumped throughout the body by the heart muscle, they take in nutrients from the intestines and oxygen from the lungs, which they pass on to all the body´s cells. (Things like this, which cells want, move freely between and then through membranes by the process of random movement called diffusion, which actually happens quite fast. It is sometimes accelerated by tiny pumps on the surface of cell membranes.) Chemical waste and carbon dioxide are taken from cells into outgoing vessels (arteries) which take waste to the kidneys to be excreted, and carbon dioxide to be exhaled in the lungs, before reentering the heart. Blood cells also help fight infection and help the body heal itself.
Muscles cells group together to form long fibers which are attached to the ends of bones to make a muscle. When stimulated by nerves attached to them, proteins in the muscle cells slide over each other, making the muscle shorten (and appear bigger), causing movement.
The nervous system is built of nerve cells, or neurons. Their purpose is to receive and send information. While some are "dead-ends", stimulated by changes in the environment or stimulating muscle or glands, most neurons outside the brain, and all of them inside it, are connected only to each other, forming complex and ever-changing webs. (Nerve cells are each surrounded by a Schwann´s cell, which forms a sheath around the nerve to insulate and thus quicken transmission of the electrical impulse, and protect the nerve.)
Pumps on the membrane of the neuron force certain electrically charged particles outside the cell, and closed gates on the membrane keep them out. The neuron is stimulated when neurotransmitters (chemical "keys") from the axonal knobs of another neuron cross the synaptic gap between the two and fit into "locks" on its dendrite´s surface. This causes gates on the membrane near the synapse to fly open, and charged particles to rush into the cell. As they enter, they force gates directly in front of them to open, so that an electrical impulse travels across the entire cell, down the axon, until it reaches the opposite synapse, where it causes the release of neurotransmitters that may stimulate the next nerve cell.
Firing takes less than a millisecond, and almost immediately after "firing," membrane pumps restore the electrical imbalance across the membrane. The neuron is then ready to be stimulated again.
Parts of the Brain
Neurons form complex and ever-changing webs which make possible the speed, flexibility, and durability of our thoughts. Rather than being completely centralized in one place in the brain, mental processes are "distributed" (i.e., they occur throughout the brain) and can use different pathways, which is important for managing many different thoughts as we must do. Still, some functions are partially centered in certain compartments of the brain.
How does a body and brain develop from a single baby-cell? First, the cell divides into many unspecialized or stem cells. Then, according to chemical signals from the mother´s womb (and later from the baby cells themselves) cells begin to differentiate as parts of their DNA information become permanently turned off, and they become a specific type of cell. Later, the babies "chemical conversation" with its mother will determine how much and in what directions it´s now specialized cells should grow, forming organs and giving the body it´s shape.
Like many aspects of cognitive research, the development of the brain is not well understood. Whatever will or will not be learned in the future, we think it safe to say it will remain forever wonderful. In the next sections we will present theories related to cognition without explaining them directly in neurological terms.
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