Biological psychology, also known as behavioral neuroscience and psychobiology, is the study of physiological processes and how they affect human behavior. According to this concept, behavior is inextricably related to somatic or physiological experiences that are created by the brain’s interpretation of sensory impingement. Therefore, biological psychology presumes that the mind and body have an interdependent relationship, and that behavior is fueled by sensory perceptions based on physiology.
Avicenna (980-1037 C.E.), a Persian physician, was the first scientist to discern a relationship between psychology and physiology. This runs counter to the dualistic point of view held by Plato and Aristotle, and later, by René Descartes. In his work, Meditations on First Philosophy, Descartes put forth his belief that the mind, which he thought to be the seat of emotions, was a separate phenomenon from the biological brain, which had more to do with intelligence. He felt emotional phenomena, then, was not dependent on the physical substance of brain matter.
During the 19th century, psychologist William James, in his seminal textbook The Principles of Psychology (1890), advanced the idea that psychology should be studied in conjunction with biology. James's point of view attracted much attention since, in addition to being a psychologist, he had received training in physiology. Another psychologist, Knight Dunlap, advanced the concept of biological psychology by writing the book An Outline of Psychobiology (1914). He also founded and published the journal, Psychobiology.
Through the study of biological psychology, neuroscientists and social scientists hope to improve the quality of life of those who may be suffering from cognitive disorders that are sometimes accompanied by physical deficits. Therefore, both autism and Alzhemier's Disease are of great interest to biological psychologists. In the case of autism, the person afflicted may experience severe and quite noticeable kinds of motor disturbances. With Alzheimer’s patients, in addition to possible physical deterioration, cognitive and behavioral abilities become more and more impaired as the disease progresses.
The field of biological psychology is also concerned with finding solutions to psychiatric disorders like schizophrenia and clinical depression. It is generally believed that the emotions and behaviors are associated with chemical imbalances in the brain, and dysfunctional transmission of neurons. Neurotransmitters are naturally occurring chemicals in the brain that relay signals between nerve cells. When their action is disrupted, it generally has a deleterious effect on a person’s mood. The disruption can cause depression, or auditory and/or visual perceptions, in the case of schizophrenia.