Abnormal Psychology. William J. Ray

universe, and that was that.

      Beginning in the fourteenth century, however, a new spirit began to emerge in Europe. It influenced art, literature, politics, and science. In art, there was a desire for a sense of realism, which led artists such as Leonardo da Vinci to carefully study the human body. He performed dissections on animals and human cadavers to carefully reveal the structure of organs. Figure 1.5 shows one of da Vinci’s drawings.

      With the detailed drawings of human anatomy created by da Vinci and other artists of the time, there was now the possibility for the scientists of the 1600s to consider function. One important focus was the manner in which the nervous system allows us to perform both involuntary and voluntary functions. How physiological processes are involved in remembering, moving, feeling, and thinking became topics of consideration. Mechanical models emerged, as illustrated by the writings of French philosopher René Descartes (1596–1650).

      Figure 1.5 Leonardo da Vinci Drawing of the Structure of Human Organs

      Public domain

      Descartes was intrigued by mechanical machines such as the large clocks in Europe with moving figures or water displays in large fountains. By analogy, he assumed that reflexes or involuntary actions of organisms were based on similar principles. Thus, moving your hand quickly from a hot stove or even digesting food was seen as a mechanical operation. For Descartes, all animal behavior could be explained by mechanical principles as could human involuntary actions. In Figure 1.6 from Descartes’ work, you can see the mechanical means by which a hot fire would cause an involuntary or reflexive movement.

      The important distinction that continues today is that behavior can be categorized as either involuntary or voluntary. Voluntary actions such as thinking or consciously performing an act were different in that they required a mind, and humans were the only organism to have a mind, according to Descartes. By thinking, humans can know with certainty that they exist—thus, the famous philosophical statement of Descartes, “I think, therefore I am.”

      Given the understanding that the bodies of animals are totally mechanical and that humans have both a body and a mind, Descartes created a mind–body distinction that science has had to face in its explanations. The problem is, how can a material body including the brain be influenced by an immaterial process such as the mind? How can a thought influence a cell in the brain?

      Figure 1.6 Involuntary or Reflexive Movement

      Source: Public domain

      Although today we generally talk about the mind–body problem, the metaphysics of Descartes’ era would often make the distinction between body and soul. Descartes answered this problem by suggesting that the rational soul was able to control the mechanical body by having both functions come together in one particular organ of the brain, the pineal gland. It is in the pineal gland, Descartes claimed, that the mind not only controls the body but also senses the nature and flow of the mechanical nervous system.

      Today, most neuroscientists see the mind as resulting directly from the brain and that the mind–body problem is not actually a problem to be solved. However, the question of whether particular behaviors seen in individuals with mental illness represent involuntary processes performed without the benefit of a conscious mind has plagued our legal understanding of mental illness.

      In the 1600s, science as a way of knowing about the world began to emerge. At the beginning of this period, prior authorities such as Aristotle or the Church determined the worldview. In this century, Galileo led a movement that would eventually replace authority with experimentation. This movement toward experimentation was greatly aided by Galileo’s own inventions, such as the telescope, the thermometer, an improved microscope, and a pendulum-type timing device. Each of these instruments allowed people to experiment and answer for themselves the questions of nature. With Galileo’s work, a new science based on observation and experimentation was beginning. Galileo was part of a revolution that was to challenge authority. In the 1680s, Newton’s classic work Principia was published (Newton, 1729/1969). Designated by science historian Gerald Holton (1952) as “probably the greatest single book in the history of science,” this work describes Newton’s theories of time, space, and motion as well as his rules of reasoning for science.

      Concept Check

       Concepts in understanding psychopathology date back thousands of years yet still influence our views today. What important contributions did the ancient Greeks and Romans—particularly Pythagoras, Hippocrates, and Galen—make to current views of psychopathology?

       Describe the shift from authority to science as a way of knowing what happened during the Renaissance. Specifically, what did Leonardo da Vinci, René Descartes, Galileo, and Isaac Newton contribute during this period that led to this shift?

      Discovering the Function of the Brain in Behavior and Psychopathology

      The developing spirit of science during the 1600s began to set the stage for a new breed of scientists to emerge. One of these scientists was an English doctor, Thomas Willis (1621–1675). He was interested in neurology and in fact coined that term along with a number of anatomical terms such as lobe, hemisphere, and corpus striatum. He may also have been the first person to use the word psychology in English.

      Willis sought to combine the study of brain structure and function. He suggested that lower-brain structures were responsible for more basic functions of life and that these structures could be found across a variety of vertebrates. On the other hand, those structures located higher in the brain must be involved in more advanced processes seen in higher organisms such as humans. Implicit in this idea is a break with Descartes’ suggestion that animals are only machines.

      Figure 1.7 Gray Matter and White Matter in the Brain

      Source: CC BY 2.5 John A Beal, PhD Dep’t. of Cellular Biology & Anatomy, Louisiana State University Health Sciences Center Shreveport, http://www.healcentral.org/healapp/showMetadata?metadataId=40566 (Internet Archive of file description page)

      By the end of the 1700s, the nervous system had been completely dissected and the major parts described in detail. The brain was seen to be composed of gray matter and white matter, terms we continue to use today (see Figure 1.7). White matter was involved in moving information to and from the gray matter. Today, we have a fuller understanding of brain structure, with the thin outer shell of the brain consisting of cells, which appear to be a darker color and are thus called gray matter. Underlying this are the axons, which transfer information throughout the brain. Their myelin sheaths are lighter in color, and thus these areas are referred to as white matter. Myelin is made up of fats and proteins and wraps around axons like insulation does around electrical cables, resulting in an increased speed of information transmissions.

      Also by the 1700s, scientists knew that there was a general pattern in all human brains in how the brain was structured in terms of surface structures or bumps, which were called gyri, and the grooves between them, referred to then and now as sulci and fissures. The present-day terms used to describe parts of the brain also come from Latin, so the lobes of the brain are the frontal lobe, parietal lobe, temporal lobe, and occipital lobe. This can be seen in Figure 1.8.

      Scientists of the 1700s also determined that the nervous system had a central division consisting of the brain and spinal cord and a peripheral division consisting of nerves throughout the body (see Figure 1.9).

      Figure 1.8 The Lobes