Читать книгу The Behavior of Animals - Группа авторов - Страница 68

A major problem in the study of both motivation and emotion is that different authors use these concepts in different ways. The concept of a behavior system is useful in understanding many of these differences. I have proposed perceptual, central, and motor mechanisms as the basic structural units of behavior. These entities are viewed as corresponding to structures within the central nervous system. They consist of an arrangement of neurons (not necessarily localized) that acts independently of other such mechanisms. Perceptual mechanisms analyze incoming sensory information and solve the problem of stimulus recognition. An example is the releasing mechanism discussed in Chapter 2. The motor mechanisms are responsible for coordinating the neural output to the muscles, which results in recognizable patterns of movement. The central mechanisms coordinate the perceptual and motor mechanisms and also provide the basis for an animal’s mood or internal state. These units are called behavior mechanisms because their activation results in an event of behavioral interest: a particular perception, a specific motor pattern, or an identifiable internal state.

Behavior mechanisms can be connected with one another to form larger units called behavior systems, which correspond to the level of complexity indicated by feeding, sexual, and aggressive behavior (Baerends 1976; Hogan 2001). The organization of the connections among behavior mechanisms determines the nature of the behavior system. Thus, a behavior system can be considered a description of the structure of behavior. A pictorial representation of this concept is shown in Figure 3.1.

Figure 3.1 Conception of behavior systems. Stimuli from the external world are analyzed by perceptual mechanisms. Output from the perceptual mechanisms can be integrated by central mechanisms and/or channeled directly to motor mechanisms. The output of the motor mechanisms results in behavior. In this diagram, central mechanism I, perceptual mechanisms 1, 2, and 3, and motor mechanisms A, B, and C form one behavior system; central mechanism II, perceptual mechanisms 3, 4, and 5, and motor mechanisms C, D,and E form a second behavior system; 1-A, 2-B, and so on can also be considered less complex behavior systems. (From Hogan 1988).

Causal factors not only motivate behavior, they can also change the structure of behavior; that is, they have developmental effects. The formation of associations and the effects of reinforcement are developmental processes, and developmental processes have played an important role in many theories of motivation, especially in experimental psychology (see Hogan 1998). In this chapter, I will restrict the term motivation to the modulating effects causal factors have on the activation of behavior mechanisms. Development refers to the permanent effects causal factors have on the structure of the behavior mechanisms and on the connections among the behavior mechanisms and is discussed in Chapters 7 and 8. Emotion is considered to be one of the consequences of activating behavior mechanisms and will be discussed later.