Hippocrates was right: The brain is the organ of the mind. The mind is a set of processes (feeling, thinking, initiating action, and so on) carried out by physical activities in the brain. The brain, of course, does not work in isolation from the rest of the body or the environment. It needs input from sensory nerves, is affected by chemicals carried in the blood, and acts through motor nerves and (to a lesser degree) hormones. Yet the brain is the center of all that we call the mind: It contains the mechanisms needed to analyze all inputs and organize all outputs.
In reviewing this chapter, so full of terms and details, you may find it useful to keep the following broad points in mind:
1. The value of a functionalist perspective As you review the structures described in this chapter—ranging from the little ones, such as synaptic vesicles and dendrites, to the big ones, such as the cerebellum and autonomic nervous system—ask yourself, for each: What is it for? That is, what role does it play in the workings of the larger machine that is the human being? How is it related to other parts of the machine, and how can variations in it affect human behavior? The structures are a lot easier to remember, and certainly more interesting, if you think of them in terms of their roles in a larger system rather than as isolated entities.
2. Uses of the hierarchical model The hierarchical model described in this chapter (summarized in Figure 5.24 on p. 176) provides a way to organize thinking about the nervous system. It is a useful memory scheme because it allows us to see each part in relation to the whole. It summarizes, in a very general way, the effects of damage to different parts of the nervous system. As you review the discussion of the central nervous system, tie the bits and pieces together into the hierarchical model.
3. Brain science in relation to the rest of psychology As researchers discover more about the brain, knowledge about it becomes relevant to broader areas of psychology. In later chapters, you will read about the brain in relation to psychology’s attempt to understand basic processes of motivation, sensation, memory, and thought. Still later, you will read of brain-based theories of mental disorders and of drugs that are believed to alleviate specific mental disorders through their interactions with neurotransmitters. Your review of this chapter will be more effective if you try to anticipate the ways that each topic discussed here might be relevant later. Ask yourself: Why might a psychologist want to know about this structure or process? You may be surprised at how often you come up with a good answer.