Brain Summary Though Not Much

Brain Summary

Though not much to look at on the surface, the brain is one of the most complex -- if not the most complex -- natural marvels known to man. With many billions of neurons serving to make connections in the brain, it is far more complex and varied in its abilities than even the most complex and powerful computers. Different functions stem primarily from different areas of the brain, but it takes a complex interaction to produce most behaviors. There are several techniques for studying the brain in general and the different areas of the brain involved in certain activities and behaviors. Electroencephalograms (EEGs) measure electrical activity in the brain through electrodes placed on the exterior of the head, while positron emission topography (PET) uses an injected radioactive dye to measure blood flow and activity in the brain by tracing the radiation Both functional magnetic resonance imaging (fMRI) and transcranial magnetic simulation use magnetic fields to create three-dimensional images of the brain that can show activity as well as structure.

pp. 81-2

Neuroscience is being used in several key ways to help individuals with damaged brains and/or nervous systems. Deep brain stimulation, in which electrodes are placed deep in the brain tissue and used to electrically trigger precise areas of the brain have been used to "wake up" patients in a semi-conscious state due to brain trauma, and techniques involving EEGs are being develop for patients that have full brain activity but cannot communicate. The cerebellum is the part of the brain responsible for movement and balance, while the adjacent and continuous reticular formation is capable of instantly activating many other parts of the brain.

pp. 83-84

The thalamus acts as an organizer in the brain, distributing information form higher up to the cerebellum and the medulla. The adjacent hypothalamus helps to regulate homeostasis and also regulates critical functions such as eating, self-preservation, and sexual activity. The limbic system, which includes certain "pleasure centers," runs through the brain's central core and also regulates basic emotions and behaviors, such as appetite, reproduction, and aggression. The limbic system, along with the hypothalamus, is also very involved in the process of learning and memory, which was shown unintentionally when some individuals with epilepsy had portions of their limbic system removed. The cerebral cortex is a more recently evolved piece of organic machinery, and allows human to think and make complex judgments.

pp. 85-6

The brain can be understood in terms of its lobe-like structures, or it can be mapped out according to the regions that seem to dictate and influence certain behaviors and processes. The three major areas of the brain in this schema are the motor areas, the sensory areas, and the association areas, though in reality almost all human functions and behaviors involve interactions between these areas. Interestingly, large and imprecise movements have been found to originate in a very small space of the motor areas, whereas more precise yet much smaller movements require large brain areas. The sensory area consists of three composite areas -- the somatosensory area, the auditory area, and the visual area.

pp. 87-8

The association areas of the brain are believed to control higher-level thinking and processes that regulate behavior in a larger sense, such as turning Phineas Gage from a hardworking and responsible individual to an aggressive, scheming alcoholic after an iron bar was thrust through his brain. Similar injuries and careful observation make up much of what is known about these areas of the brain, as direct findings and observations are not so easily obtained. The phenomenon of neuroplasticity shows that functions can be moved to different areas of the brain following an injury, however, and new connections and even new neurons are created in the brain throughout life. Stem cells also hold great promise in being able to become specialized neurons and brain cells and thus repair brain damage or degradation.