BASIC BRANCHES OF PSYCHOLOGY One of the major branches of psychology is neuropsychology or biopsychology. It looks at the different biological factors that affect mental processes and behavior. It looks at the phenomena associated with sensation and sensory perception. This is a relatively new field of psychology because it depends on understanding things like neurotransmitters and the different mental processes linked to different parts of the brain. The field originated in the 1870s, when a researcher named Paul Broca mapped speech production to certain areas on the left frontal gyrus of the brain. Another researcher, Carl Wernicke, mapped out the areas of the brain that determine the ability to understand the spoken word. It was discovered by these researchers that there is lateralization of certain cerebral processes so that an injury on a specific side an of the brain means a different impact on mental and physical functioning. Many other things were discovered by studying people who had major brain injuries. One infamous patient who was studied was Phineas Gage, who had a rod impaling his frontal lobe and survived. He developed significant social and interpersonal difficulties afterward, which were examined; the findings helped doctors understand the role of the frontal lobe on thinking and behavior. In modern science, there is the field of behavioral neuroscience that looks at the interplay between neurology and psychology. Because of the ethical issues regarding the study of the nervous system in humans, many studies are done on neural circuits as they relate to learning and memory in rats. There are doctors and researchers that use neuroimaging techniques to take specialized images of the human brain. The differences in brain structures as they relate to psychological differences in humans can then be studied ethically. Brain damaged patients or those with brain tumors can help determine which parts of the brain are associated with what kinds of neurological, emotional, and cognitive defects. A related field is evolutionary psychology, which looks at thinking patterns and personality traits that have changed over the course of human development. According
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