Physiological psychology is a branch of psychology that is concerned with the biological basis of behavior, as opposed to the social influences on behavior. It is also known as biological psychology, biopsychology, or psychobiology, and is closely related to neuroscience. Physiological psychologists study the electrical and chemical functions and activities of the brain, and how they relate to a person's mental experience and behavior. This branch of psychology is an approach to psychological research, which is used to study many different psychological phenomena.
There are a number of areas of focus within physiological psychology. Most research focuses on the brain, and the reactions that take place at a neurological level. In the beginning of the field's development, sensation and perception were the focus, such as the brain's response to familiar smells. Neurotransmitters, such as serotonin and dopamine, are frequently studied by physiological psychologists, including the development of psychiatric medications that address chemical imbalances in the brain.
Some subjects commonly thought of as purely social can be studied from the viewpoint of physiological psychology. Research on mirror neurons, for example, helps to explain how people empathize with other people. Mirror neuron research looks at how neurons in one brain are activated when that person or animal is watching someone else perform a behavior that activates those same neurons. This is useful to help people who struggle with social interaction, such as people with autism.
Many different techniques are used in physiological psychology. Machines to view the brain, such as in magnetic resonance imaging (MRI), are often used to study the brain's physical structures and functional activity. Other methods include electrodes on the head that monitor the brain's activity, or wires inserted into the brains of animals that stimulate different brain structures. People who have experienced brain damage are frequently studied to determine which part of the brain was damaged and the corresponding effects of the damage on the person's behavior.
Surgery is sometimes used in this branch of psychology research, particularly in animal research, but also in humans who are undergoing brain surgery for other conditions, such as cancer or epilepsy. Surgeons investigate the effects of stimulation or damage to a given brain structure on behavior and, in the case of human brain surgery patients, on the subjective experience of the person. Surgery is used less in this field as accurate and non-invasive brain imaging techniques became available.
Animal research is a controversial ethical issue in physiological psychology. Experimentation on animals is very important for a great deal of research in this field and can yield research findings that help many people. Ethical guidelines for the care and treatment of research animals must be followed by researchers, but animal suffering still occurs even if it is minimized. Animal rights groups in particular may oppose the use of animals in this research.