The Scientific American article is entitled The Neurobiology of Trust. In both cases, the studies reported indicate that by applying oxytocin in the form of a nasal spray the level of “trust” displayed by people engaged in specially orchestrated, financially oriented social interactions can be increased by a statistically significant amount. Whether these experiments illustrate a manipulation of a personal trust infrastructure, or a manipulation of the anticipated interaction outcome assessment within such a personal trust infrastructure, we find this to be a most interesting illustration of the physiological basis of social systems. We will delve into this concept in much more detail in the coming sections and in subsequent chapters.

The human brain is the unique feature of the species that has enabled its dominance in the physical ecosystem of the earth. About the size of a grapefruit with a cranial capacity of approximately 1500 cc, the brain sits at the anterior end of the spinal cord. It is encased in an exoskeleton component call the skull. While the human body is based on an endoskeleton, the skull and the vertebrae of the spine exhibit the excellent support and protection characteristics of exoskeletal structures. Our typical visual image of the brain is that of the partially bifurcated, semi-globular form whose surface is marked by deep fissures giving something of the appearance of a tightly coiled mass of rope. This visible, outer area of the brain is composed almost completely of neurons, with their soma, which are naturally gray in color, visible at the outer surface. This gives rise to the image of the brain as gray matter.

The brain structure encased in a bony skull is an evolutionary feature that developed early in the emergence of the vertebrates. The human species is notable for its brain size, relative to its body size, although some of the larger primates have almost comparable relative sizes. While the cranial capacity of the skull is relatively larger in humans that in other primates, the brain size is really enhanced through the development of folding of the mass of neurons into ridges and grooves, termed gyri and sulci respectively. This mechanical orientation of neurons allows for increased surface area of the brain, which, in turn, allows for more neurons to be supported by the same arrangement of glial cells. Moreover, the amount of white matter, that is the number of neuron axons, appears to be the really distinguishing feature of the human brain. This would effect a larger number of synapses, reinforcing the idea that these are the determining factor of cognitive power.

If one visualizes one’s own brain as existing as a mass above and behind the eyes, then a number of common features of all human brains can be identified. First, the visible outer area, that area of gray matter, is termed the cerebrum and it is divided into two hemispheres by a deep fissure that completely divides the left half of the brain from the right half, save for a connecting bundle of fibers called the corpus callosum located midway between the front and back extremes of the hemispheres. A number of general lobes or areas of the brain provide location coordinates for specific functional sections that have been identified through various forms of research. The front portion of each hemisphere is termed, appropriately enough, the frontal lobe. The rear portion of each hemisphere is termed the occipital lobe, and a rather narrow section of each hemisphere between these two lobes is termed the parietal lobe. On each side of the brain, looking a bit like earmuffs, are the temporal lobes. Functional areas of the brain are then located through references to these lobes. For example, in the lower, rear portion of the left hemisphere’s frontal lobe is found Broca’s area; a neural network that is in particular heavily involved in language processing.

The spinal cord connects in to the bottom of the brain through a structure called the brain stem. A region between the brain stem and the cerebrum is termed the diencephalon. It is in turn comprised of the hypothalamus, the thalamus and the epithalamus. These sections are largely responsible for maintaining a stable internal environment within the human body. For example,

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