Читать книгу Abnormal Psychology - William J. Ray - Страница 91

Given that the human brain has some 86 billion neurons with some 5,000 synapses, each resulting in trillions of synaptic connections, it is clear that a higher-level analysis of brain function is necessary (Goldstone et al., 2015). A variety of brain imaging techniques have allowed for a network analysis that describes which areas of the brain are involved in specific tasks. The first step has been to describe the normal processing of networks such as those involved in rewards or fear. The next step is to understand how these networks become involved in more psychopathological states such as addiction and anxiety. The goal now is to better understand how the basic network becomes involved in psychopathological processes. Is it a lack of connections between brain areas, or is there a reorganization of normal processes that underlies specific psychopathologies? This is one question scientists are asking.

Following the discovery of brain areas involved in particular functions such as Broca’s area in the 1800s, researchers searched for specific areas involved in particular cognitive, emotional, and motor processes. With the increased sophistication of brain imaging technologies came a greater ability to view the manner in which certain parts of the brain work together as well as large-scale turning off and turning on of various areas. Some processes involve a pathway using only a few neurons. Being startled by a loud noise or touching a hot stove are examples of processes that have short neuronal pathways. Other processes use a more complex series of connections. More voluntary and complex processes use a much larger series of neuronal connections referred to as networks.

Researchers are now turning to examine how specific brain areas work together as networks. This search has also extended to psychopathology. Psychopathology can be seen in terms of problems involving either particular brain areas or the connections between areas that make up the network.

We all experience the brain organizing itself in terms of various networks throughout our day. One of the most familiar is sleep. Another is waiting for a lecture to start, when we just let our mind wander. Both of these cases are not responses to external stimuli but are self-organizing processes that occur. These types of processes are controlled by a large number of neurons working together in the form of a network.

Networks allow our brains to process information efficiently (Laughlin & Sejnowski, 2003; Sporns, 2011). Overall, cortical networks are influenced by experience and designed to be efficient in terms of connections between neurons in the network. This efficiency allows for less use of energy. One way energy is conserved is through not having every neuron connect with every other neuron.