Information processing is the study of the flow of information from one location to another and how it gets transformed, reconstituted, or interfered with. The information superhighway is the technological system that makes full use of these ideas.

Information processing systems:

All information processing systems seem to have these general components.
receptors--senses
processors--transform, interpret, integrate, select--attention, set, automatic and controlled processes.
memories--long term, short term, working, STSS.
effectors--muscles, glands

The nervous system, and particularly the brain, is the part of the body that is the major locus of cognition. It receives information from the senses and "processes" it. Evidence that the brain is particularly important is that it uses a far greater percent of the blood supply than its percent weight of the body, and according to some physiologists, approximately half of the genome is directly related to brain function.

The human nervous system has a fairly complex gross structure, and an incredibly complex microstructure. Grossly one can identify many different parts. The central nervous system consists of the brain, with its many substructures, and the spinal cord. The peripheral nervous system consists of the cranial nerves, the spinal nerves, and the visceral nervous system.

Neurons: The human nervous system contains approximately 100 billion cells identified as neurons. It also contains trillions of other cells called glial cells, whose functions are to support the neurons in many different ways. Neurons are specifically designed to transmit information. They generally receive information in the form of electrochemical activity received through synapses at one end, and deliver information through other synapses about it elsewhere. Neurons may receive information via a few to many thousands of synapses, and send information via a few to many thousands of synapses. Let's look at the structure and functions of neurons (click here). (Axons, cell body, dendrites, synapses, neurotransmitters, excitatory and inhibitory synapses, resting potential, spike or action potential, all or none principle, absolute and relative inhibition, summation)

Synapses and Neurotransmitters.  Neurons, when active, produce an action potential which travels down the neuron. Some synapses are excitatory synapses and increase the likelihood that the neuron they synapse on will become active, or fire. Some are inhibitory and lower the likelihood that the adjacent neuron will fire. So far it seems that each neuron either has only excitatory or inhibitory synapses, but not both. The transfer from one neuron tto another is by biochemical means. A synapse releases neurotransmitters which in a complex manner change the electrical potential of the next neuron. There are many different neurotransmitters with different modes of action. Some you may have heard of are acetylcholine, norepinephrine, glutamate, aspartate, GABA. Some newly discovered neurotransmitters are called peptides, which are longer lasting and perhaps act more slowly than the others.

Central Nervous System: The CNS contains a vast network of interconnections of neurons. Some of these neurons are connected locally, within a few millimeters, and some of them go from one part of the brain to another. There are major pathways which connect many neurons in one area to another, and there are smaller pathways which connect fewer neurons between sites. Some of the lower centers of the brain serve as relay stations to connect neurons coming from one location to another, and also to divert other signals to supporting functions. Almost all of the neurons that project to the cortex synapse in the thalamus. Also there are projections from each cortical region back to the thalamus. There are areas of the brain that have primary functions that are fairly well known , and other areas for which the functions are less clear. Although some areas of the brain are more active for some activities than others, the whole brain is active to some extent at all times.

Brain and cognitive functions. There is much evidence that different parts of the brain have different functions. Some of the information from the eyes map topographically with loci in the occipital cortex. There are localized motor areas relating to different parts of the body in the frontal lobe, and the same kind of sensory locations in the parietal lobe. New research has suggested that it is not necessarily that simple. Interactions among the systems have been demonstrated. The complexity, and the problems of how the different systems interrelate to form single activities and unique psychological experiences are hardly understood at all. We will discuss some of the complexities during this semester.

The following is an introduction to the nervous system by Dr. Chudler from Washington University in St. Louis. I recommend that you spend some time perusing it, especially if you do not know anything about the nervous system. This URL, http://faculty.washington.edu/chudler/introb.html, is the home page for his discussion. This collection, essays, and links contain a wealth of information about the brain and other aspects of the nervous system. I recommend your exploring it. I do not have time in this course to discuss much of it.
In Brain Basics, check out divided brain and functional divisions of the brain
This URL is the introduction to Brain Basics. http://faculty.washington.edu/chudler/introb.html#bb

If we want to pat ourselves on the back, we can note that the human brain, in particular the cerebral cortex, is larger than that of almost all of the other species on earth.  A comparison of different brains. However, it can also be noted that at least some of the neurotransmitters in the human nervous system are identical to those of lower animals. The sea slug, which has only a very few neurons, has the same neurotransmitters that we do.