In Chapter 3, biological psychology is discussed. Much time is spend conveying the function and components of neurons, the message conveyors of the neurological system, and of the brain, the control center of the system. Genetics, the spinal cord, and the endocrine system are also mentioned, though to a lesser extent. One of the most interesting portions, though short, conveys a story that I first heard in high school psychology. This is the story of Phineas Gage.
Gage was working as a railroad foreman in rural Vermont. During an average work day, which involved breaking up rock formations with gunpowder, the tamping iron he used to press the gunpowder in was rocketed upward from an explosion, driving it through his skull and destroying much of his frontal lobe, as well as his left eye. He miraculously survived, but was described as being "no longer Gage." The accident left him, apparently once a happy and level-headed man, "fitful, irreverent, indulging at times in the grossest profanity." The drastic personality change is quite disturbing, but when considering the importance of the brain to human anatomy, it isn't hard to believe such an accident could change a person so significantly.