Biological psychology, of biopsychology, is the application of the principles of biology to the study of mental processes and behavior, that is the study of psychology in terms of bodily mechanisms. The view that psychological processes have biological (or physiological) correlates, is the basic assumption of the whole field of biological psychology. Through a variety of research methods, psychologists in this field hope to uncover information that enriches human understanding of their own mental processes, as well as providing valuable data that enable those in medical fields to better treat patients with a variety of disorders, both physical and mental.
Biopsychology has been a prominent field of psychology from the start in Europe and North America and remains a major area of research and instruction in many countries. In the last two centuries, biopsychology has found new ways to answer old questions, has tackled important new questions, and has abandoned some problems as poorly defined. Carefully designed behavioral experiments and innovative biomedical techniques have been essential to its progress.
The current scope of biological psychology includes the following themes: Evolution of brain and behavior; development of the nervous system and behavior over the life span; psychopharmacology; sensory and perceptual processes; control and coordination of movement and actions; control of behavioral states (motivation), including sex and reproductive behavior, and regulation of internal states; biological rhythms and sleep; emotions and mental disorders; neural mechanisms of learning and memory, language and cognition; and recovery of function after damage to the nervous system. Developing from biological psychology and overlapping with parts of it are such fields as behavior genetics as well as hormones and behavior. Through all these methods, biological psychology is a hopeful domain, one that has much to offer in terms of improving the quality of life of the healthy as well as those suffering from disorders.
Synonyms to Biological Psychology include Biopsychology, Behavioral Neuroscience, and Psychobiology. Physiological psychology is another term often used synonymously with biological psychology, though some authors would make physiological psychology a subfield of biological psychology, with an appropriately more narrow definition. The focus of study of physiological psychology is the neural mechanisms of perception and behavior through direct manipulation of the brains of nonhuman animal subjects in controlled experiments.
The history of biological psychology is a major part of the history of modern scientific psychology. The study of biological psychology can be dated back to Avicenna (980-1037 C.E.), a physician who in The Canon of Medicine, recognized physiological psychology in the treatment of illnesses involving emotions, and developed a system for associating changes in the pulse rate with inner feelings, which is seen as an anticipation of the word association test. Avicenna also gave psychological explanations for certain somatic illnesses, and he always linked the physical and psychological illnesses together. He explained that "humidity" inside the head can contribute to mood disorders, and he recognized that this occurs when the amount of "breath" changes: Happiness increases the breath, which leads to increased moisture inside the brain, but if this moisture goes beyond its limits, the brain would lose control over its rationality and lead to mental disorders.
Biological psychology as a scientific discipline later emerged from a variety of scientific and philosophical traditions in the eighteenth and nineteenth centuries. In philosophy, the first issues is how to approach what is known as the "mind-body problem," namely the explanation of the relationship, if any, that obtains between minds, or mental processes, and bodily states or processes. Dualism is a family of views about the relationship between mind and physical matter. It begins with the claim that mental phenomena are, in some respects, non-physical. In Western Philosophy, some of the earliest discussions of dualist ideas are in the writings of Plato and Aristotle. Each of these maintained, but for different reasons, that human "intelligence" (a faculty of the mind or soul) could not be identified with, or explained in terms of, his physical body. However, the best-known version of dualism is due to René Descartes (expressed in his 1641, Meditations on First Philosophy), and holds that the mind is a non-extended, non-physical substance. Descartes was the first to clearly identify the mind with consciousness and self-awareness, and to distinguish this from the brain, which was the seat of intelligence.
The question then, is how do these separate and entirely different aspects of living beings, the mind and the body, relate? Some, like Descartes, proposed physical models to explain animal and human behavior. Descartes, for example, suggested that the pineal gland, a midline unpaired structure in the brain of many organisms, was the point of contact between mind and body. Descartes also elaborated on a theory in which the pneumatics of bodily fluids could explain reflexes and other motor behavior. This theory was inspired by moving statues in a garden in Paris.
Other philosophers also helped to give birth to psychology, also relating its subject matter to biology. This view, that psychological processes have biological (or physiological) correlates, is the basic assumption of the whole field of biological psychology. One of the earliest textbooks in the new field, The Principles of Psychology by William James (1890), argues that the scientific study of psychology should be grounded in an understanding of biology:
Bodily experiences, therefore, and more particularly brain-experiences, must take a place amongst those conditions of the mental life of which Psychology need take account. The spiritualist and the associationist must both be "cerebralists," to the extent at least of admitting that certain peculiarities in the way of working of their own favorite principles are explicable only by the fact that the brain laws are a codeterminant of their result. Our first conclusion, then, is that a certain amount of brain-physiology must be presupposed or included in Psychology.
William James, like many early psychologists, had considerable training in physiology. The emergence of both psychology and biological psychology as legitimate sciences can be traced from the emergence of physiology from anatomy, particularly neuroanatomy. Physiologists conducted experiments on living organisms, a practice that was distrusted by the dominant anatomists of the eighteenth and nineteenth centuries. The influential work of Claude Bernard, Charles Bell, and William Harvey helped to convince the scientific community that reliable data could be obtained from living subjects.
The term "psychobiology" has been used in a variety of contexts, but was likely first used in its modern sense by Knight Dunlap in his book, An Outline of Psychobiology (1914). Although a "forgotten man" of American psychology, Dunlap also founded the journal Psychobiology. In the announcement of that journal, Dunlap writes that the journal will publish research "…bearing on the interconnection of mental and physiological functions," which describes the field of biological psychology even in its modern sense.
For many decades, biopsychology or psychobiology has been a site of exchange of concepts, information, and techniques between psychology and the biological sciences. In many cases, humans may serve as experimental subjects in biological psychology experiments; however, a great deal of the experimental literature in biological psychology comes from the study of non-human species, most frequently rats, mice, and monkeys. As a result, a critical assumption in biological psychology is that organisms share biological and behavioral similarities, enough to permit extrapolations across species. This allies biological psychology closely with comparative psychology, evolutionary psychology, and evolutionary biology. Biological psychology also has paradigmatic and methodological similarities to neuropsychology, which relies heavily on the study of the behavior of humans with nervous system dysfunction (a non-experimentally based biological manipulation).
A psychobiologist or biopsychologist may compare the imprinting behavior in goslings to the early attachment behavior in human infants and construct theory around these two phenomena. Biological psychologists may often be interested in measuring some biological variable, such as an anatomical, physiological, or genetic variable, in an attempt to relate it quantitatively or qualitatively to a psychological or behavioral variable, and thus, contribute to evidence based practice.
Unlike other subdivisions within biological psychology, the main focus of physiological psychological research is the development of theories that explain brain-behavior relationships rather than the development of research that has translational value. It is sometimes alternatively called "psychophysiology," and in recent years also "cognitive neuroscience." One example of physiological psychology research is the study of the role of the hippocampus in learning and memory. This can be achieved by surgical removal of the hippocampus from the rat brain followed by an assessment of memory tasks by that same rat.
The distinguishing characteristic of a biological psychology experiment is that either the independent variable of the experiment is biological, or some dependent variable is biological. In other words, the nervous system of the organism under study is permanently or temporarily altered, or some aspect of the nervous system is measured (usually to be related to a behavioral variable). For example, in one treatment, a group of mice may be shown a particular color whereas the other treatment may receive no such stimulation before being measured (the dependent variable). Most commonly, these manipulations and measurements concern non-human subjects.
One set of experimental methods involves disabling or decreasing neural function.
Lesions is a classic method in which a brain-region of interest is enabled. Lesions can be placed with relatively high accuracy thanks to a variety of brain "atlases" which provide a map of brain regions in three-dimensional stereotactic coordinates. The method of electrolytic lesions involves the destruction of neural tissue by the use of electric run through. Chemical lesions destroy neural tissue by the infusion of a neurotoxin. Temporary lesions may be employed when neural tissue is temporarily disabled by cooling or by the use of anesthetics such as tetrodotoxin.
Transcranial magnetic stimulation is a comparatively new technique usually used with human subjects in which a magnetic coil applied to the scalp causes unsystematic electrical activity in nearby cortical neurons which can be experimentally analyzed as a functional lesion.
In this method a chemical receptor antagonist induces neural activity by interfering with neurotransmission. Antagonists can be delivered systemically (such as by intravenous injection) or locally (intracebrally) during a surgical procedure.
Enhancing neural function is another research method in biopsychology.
This is a classic method in which neural activity is enhanced by application of a small electrical current (too small to cause significant cell death).
A chemical receptor agonist facilitates neural activity by enhancing or replacing endogenous neurotransmitters. Agonists can be delivered systemically (such as by intravenous injection) or locally (intracebrally) during a surgical procedure.
In some cases (for example, studies of motor cortex), this technique can be analyzed as having a stimulatory effect (rather than as a functional lesion).
Some biopsychological techniques measure neural activity.
This is the measurement of the electrical activity of one neuron, often in the context of an ongoing behavioral (psychological) task.
This involves a bundle of fine electrodes to record the simultaneous activity of up to hundreds of neurons.
fMRI or functional magnetic resonance imaging is a technique frequently applied to human subjects, in which changes in cerebral blood flow can be detected in an MRI apparatus and are taken to indicate relative activity of larger scale brain regions (on the order of hundreds of thousands of neurons).
Electroencephalography (or EEG) (including the derivative technique of event-related potentials) is the method in which scalp electrodes monitor the average activity of neurons in the cortex (again, used most frequently with human subjects).
Functional neuroanatomy is the method in which the expression of some anatomical marker is taken to reflect neural activity. For example, the expression of "immediate early genes" is thought to be caused by vigorous neural activity. Likewise, the injection of 2-deoxyglucose prior to some behavioral task can be followed by anatomical localization of that chemical; it is taken up by neurons that are electrically active.
In general, biological psychologists study the same issues as academic psychologists, though limited by the need to use nonhuman species. As a result, the bulk of literature in biological psychology deals with mental processes and behaviors that are shared across mammalian species, such as: Sensation and perception; Motivated behavior (hunger, thirst, sex); Control of movement; Learning and memory; Sleep and biological rhythms; Emotions.
With increasing technical sophistication and with the development of more precise noninvasive methods that can be applied to human subjects, Biological psychologists are beginning to contribute to other classical topic areas of psychology, such as: Language; Reasoning and decision making; Consciousness.
Biological psychology has also had a strong history of contributing to medical disorders including those that fall under the purview of clinical psychology and psychopathology, also known as abnormal psychology. Although animal models for all mental illnesses do not exist, the field has contributed important therapeutic data on a variety of conditions, including:
In the past, physiological psychologists received much of their their training in psychology departments in major universities. Currently, physiological psychologists are also be trained in behavioral neuroscience or biological psychology programs that are affiliated with psychology departments, or in interdisciplinary neuroscience programs. Professional positions in Biopsychology are mainly in academic and research institutions. Training for most of these positions requires a doctorate. Each year, the National Research Council lists over one hundred research doctorate programs in neuroscience in the United States.
Division 6 of the American Psychological Association (APA) is the scholarly and professional organization related to Biopsychology. APA publishes the journals Behavioral Neuroscience and Journal of Comparative and Physiological Psychology. The European Brain and Behaviour Society publishes the journal Behavioural Brain Research and the Forum of European Neuroscience Societies publishes the Journal of Neuroscience.
All links retrieved February 5, 2013.
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