Biopsychology is the scientific study of behavior and mental processes through a biological approach (Cooper 2000). Practitioners in this field believe that biological processes may explain certain psychological phenomena, such as learning, memory, perception, attention, motivation, emotion, and cognition, particularly problems and issues connected with these phenomena. Biopsychology is also called biological psychology, psychobiology, behavioral biology or behavioral neuroscience (Cooper).
Practitioners in this new field use varied and overlapping fields of study: cognitive neuroscience, which primarily examines the brain to understand the neural workings of mental processes; psychopharmacology, which deals with the effects of drugs on psychological functions; neuro-psychology, which is concerned with the psychological effects of brain damage in humans; behavioral genetics, which deals with behavior and psychological traits; evolutionary psychology, which is involved with how psychological processes have evolved; and comparative psychology, which compares findings among different species (Cooper). The last science centers on ethology, which is the study of animal behavior in the natural habitat. The combined study of biological and psychological approaches may be considered a specialized field of either biology or psychology, although most of its practitioners are trained in university psychology departments.
Biopsychology is unlike other branches of psychology in terms of its approach rather than subject matter. It studies a full range of psychological phenomena always on a biological premise and perspective. Scholars, philosophers and researchers in previous years observed the role that biological factors play in these phenomena, but the field did not evolve until the last century (Cooper). The book, "The Organization of Behavior," in 1949 by Canadian psychologist Donald O. Hebb was a key initiative. In the book, Hebb suggested that the brain (as qtd in Cooper) produced these diverse and complex psychological phenomena in overriding the traditional belief that psychological functioning was too complex to be derived from the simpler chemistry and physiology of the brain. Hebb clinically experimented on both animals and humans and observed their daily lives critically. His findings became a controversial basis for biopsychological analysis in the year his book was published. It was an unexplored field at that time and few universities even used the new term "biopsychology" or offered courses on the biology of psychological processes (Cooper). Yet, today, it is one of the most active fields in psychology: bio-psychologists are now employed to teach and conduct research.
Several academic journals specialize on bio-psychological research as well.
E. Chudler (2001) proposed that behavior forms out of both genetic and environmental factors. It is proximate if it is mechanistic and environmentally stimulated or genetically (or physiologically) behind the behavior. It is ultimate if it has evolutionary significance and explains why natural selection favors it. Innate behavior, on the other hand, is developmentally fixed as genetically programmed and not subject to environmental variations (Chudler). Chudler also proposed ethology as the evolutionary approach to behavioral biology or biopsychology. Ethology, as previously mentioned, is the science of animal behavior in the natural habitat. He also saw behavior as an evolutionary adaptation to the natural ecological conditions in and by animals, whom he believed to behave in a way that would maximize their fitness, this fitness, in turn, as determined by the number of offspring (Chudler).
Humans and animals go through maturation and learn, according to Chudler. Maturation is genetically determined, but learning involves a change in behavior and based on experience (Chudler). This is why physical maturation is not necessarily accompanied by, or means the same thing as, learning.
Other pioneers in the combined fields included Karl von Trisch, Konrad Lorenz and Niko Tinbergen (Chudler). Lorenz experimented on young geese and discovered that a process called "imprinting" could occur. Imprinting consists of the recognition, response and attachment of a young to an adult or object (Chudler). Lorenz discovered that when the young geese were isolated, they could no longer imprint on anything. His experiment revealed an animal's innate ability to respond to a parent figure and it was during this sensitive and limited period when learning particular behaviors occurred.
Chudler, furthermore, observed that animals associate one stimulus with another, as in the case of Ivan Pavlov's dogs. This is parallel to operant conditioning in psychology, wherein a particular behavior is associated with either reward or punishment. He pointed to the connection between the nervous system and behavior as cognition, or the ability of the animal's (or human's) nervous system to perceive, store, process and use information gathered by or through sensory receptors (Chudler).
In observing and recording the internal activities of the brain and the body, bio-psychologists use research methods that manipulate and measure behavior and biological factors (Cooper). The first category came from other fields of psychology, while the second evolved primarily from neuroscience, which is the scientific study of the brain
Under the second category are the lesion methods, a lesion being a wound or an area of the body of an animal or human that has been damaged. Researchers who use these methods damage a certain part of the brain of the laboratory animal and observe and evaluate the psychological consequence of the damage on the animal's behavior. For example, a small part of a rat's brain may be surgically removed and then compare the operation of that damaged brain with the operation of the normal brain of another rat (Cooper). Or a technique called cryogenic blockade may be used in deactivating an area in the brain by bringing it to a near-frozen condition. Brain experiments on live human subjects and using lesions, are widely or universally prohibited for ethical reasons or considerations, but tests on patients with current brain damage are allowed.
In the past, neural or brain circuits, which control certain psychological processes, cross with those performing other functions and, thus, confused researchers in specifying the neural circuits involved in a given psychological process (Cooper) when a surgical lesion eliminated all neurons in the damaged area. Today, researchers use selective neurotoxins, which are chemicals that destroy specific neurons or brain cells only in a given area, such as those neurons that release norepinephrine or dopamine (Cooper).
Another category is that of stimulation methods, which activate, rather than destroy or deactivate, neurons in a specific part of the brain. Observation is afterwards made on the consequence, which determines the function of that activated part. Activation is usually done by implanting an electrode into a particular area of a laboratory animal's brain wherein a weak electrical current is passed across the tip. In past experiments, electrical stimulation activated all the neurons at the electrode tip indiscriminately (Cooper). But current neuro-chemical techniques can now selectively activate neurons that release specific neurotransmitters or have particular receptors (Cooper). Stimulation methods are used on human subjects only occasionally and only when they are conscious before surgery. A consequent observation of the impact determines what brain tissue to remove and which should be left intact.
Another set of methods takes the record of the activity of the brain or other parts of the body while the animal or human subject is psychologically or behaviorally engaged or active (Cooper). One mode is by scalp electroencephalography, which records general changes in the brain's electrical activity through disk-shaped electrodes taped on to the scalp. An electroencephalogram (EEG) indicated the voltage of the electrical signal. EEG can also be used in measuring a human subject's response to a particular sensory stimulus or to discover his or her level of physiological arousal. Other recording methods are electromyography for measuring muscle tension and electro-oculopgraphy for recording eye movements (Cooper).
Bio-psychologists who establish the relationship between emotion and cardiovascular activity measure blood pressure, the volume of blood in the other body parts and/or electro-cardiographic activity of the heart.
One of the miracles of modern-day science occurred in the early 70s when technological advances allowed or enabled scientists to look inside the human brain without needing to cut into it (Cooper). This miracle was through the imaging methods. Today, psychologists can thrillingly view the different cognitive process - perceiving, reading and imagining, among others - and investigate the biological-psychological interplay in an effort at studying and treating mental illnesses, such as schizophrenia. Imaging methods include computed tomography (CT), magnetic resonance imaging (MRI), functional magnetic resonance imaging (functional MRI) and positron emission tomography. Functional methods even produce three-dimensional images and colors, indicating the different levels of activity in each part.
Brain imaging research has developed into a new, important and exciting field of bio-psychology, now called cognitive neuroscience (Cooper). Some experiments make use of patterns of brain activity as subjects perceive different types of visual stimuli (Cooper) and researchers discover that different areas in the cerebral cortex specialize in the use or analysis of the different aspects of a visual image, e.g., position, speed, angle of movement, shape, and color.
Genetic engineering is another method introduced into the bio-psychology realm. Genetic engineering grew out of the interest in the role of genes in the development of normal and abnormal psychological traits (Cooper). Past experiments and studies under this method were limited to those that survived the…