Читать книгу Abnormal Psychology - William J. Ray - Страница 79

Information is encoded by means of action potentials in terms of frequency. That is, a loud sound would be encoded by a series of action potentials from the cells sensitive to sound intensity. A soft sound would result in fewer action potentials being fired. When observed in relation to a stimulus, action potentials are also referred to as spikes, and a number of spikes over time are referred to as spike trains. Figure 2.9 on page 49 shows different levels of firing. Understanding the nature of spikes and how they relate to information in the brain has been an important question since the beginning of the twentieth century when they were first recorded (Rieke, Warland, van Steveninck, & Bialek, 1999).

Figure 2.8 The Role of Neurotransmitters in Synaptic Processes

Source: Magistretti, P. J. (2009). Low-cost travel in neurons. Neuroscience Science, 325(5946), 1349–1351. doi:10.1126/science.118102. Retrieved from http://www.sciencemag.org/content/325/5946/1349.short. Reprinted with permission from American Association for the Advancement of Science (AAAS).

Let us now move from the consideration of neurons and neurotransmission to an overview of some of the specific neuroscience techniques that are used to understand psychopathological processes. Following an examination of these neuroscience techniques, I will move to a discussion of the networks of the brain.

Concept Check

 What are the four major lobes of the brain, and what is the primary role of each?

 “The brain’s function involves one basic element, the neuron.” What are the different parts that form the structure of the neuron, and what roles do they play?

 How does the neuron pass information on to other neurons, and how is that information encoded?

Table 2.1