Читать книгу The Handy Psychology Answer Book - Lisa J. Cohen - Страница 219

In a 2011 article about the use of neuroscience techniques in psychological research, Joseph Kable proposed that research into brain-behavior relationships should assess association, necessity, and sufficiency. Association refers to correlation. This means that two phenomena have been shown to occur together. People show increased activity in their insula on brain scans when asked to spend money. People with a certain genetic polymorphism are more likely to enjoy thrill-seeking activities than people with a different variety of that gene. In tests of necessity, scientists disrupt the neural activity and show that this impairs the psychological behavior in question. For example, if a rat’s hippocampus is removed, the rat will not be able to learn new mazes. This shows that the hippocampus is necessary for creating new memories. In tests of sufficiency, an increase in the specific type of neural activity increases the behavior in question. If rats are given a drug that increases the level of the chemical vasopressin, they show more social behavior. This supports that vasopressin is sufficient to initiate male rats’ social behavior. Research that shows association, sufficiency and necessity in a brain-behavior relationship is far stronger than research that only shows association. In sum, we have to be cautious in how we interpret neurobiological research and take care not to over-interpret the findings.

What role has the study of brain damage played in the history of neuroscience?

Long before the development of today’s brain imaging technology people still suffered from various kinds of brain disease and trauma. People had strokes or serious brain injuries, for example, from wars or from industrial accidents. By carefully studying the changes in behavior that accompanied these brain traumas and then mapping the affected parts of the brain on autopsy after the person died, scientists have learned a tremendous amount about how different psychological functions map onto different parts of the brain. As mentioned above, Alexander Luria, the famous Russian neuropsychologist, made great advances in the field by studying brain-injured soldiers in World War II. With today’s brain imaging methods, however, the lesions to the brain can be identified while the person is still alive.