SUB-SPECIALIZATIONS WITHIN THE BEHAVIORAL NEUROSCIENCES

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Neurological Basis of Behavior (PSY - 610)

LESSON 03

SUB-SPECIALIZATIONS WITHIN THE BEHAVIORAL NEUROSCIENCES

Objectives

· This would elaborate the characteristics of research in behavioral neuroscience.

· This would elaborate on the understanding of various sub-specializations within the behavioral

neurosciences which contribute to the understanding of brain and behavior relationship and how

each relates to the other areas.

According to Pinel (2002) the major areas of behavioral neuroscience research are multiple but they

have some of the following characteristics:

Range: The range subjects whose behavior has been studied through natural or experimental work

includes all organism: animals to humans. In some cases the studies have been carried out on simple

cellular mechanism.

Controls: They vary from extreme to naturalistic (as we have discussed earlier).

Research: It can be pure or applied. Research should be done purely to understand behaviors and to

develop theories and it should have no practical implications. This is known as pure research. On the

other hand research is considered to be meaningful only if there are practical implications coming out of

research data. Suck kind of research is known as applied research. Sometimes the lines are not dividing

these areas but applied research can lead to pure research and Vice-versa.

Approach: It can either be experimental or Clinical. Sub specializations differ in what they are studying

and if it involves applied clinical practice or not. Some areas such as psychobiology focus exclusively

on laboratory, experimental work whereas neuropsychology has a strong clinical focus.

The major subdivisions of Behavioral Neurosciences are as follows:

Physiological Psychology: Studies the neural modulates of behavior through direct

manipulation of the brain, using controlled experimental settings. The manipulation of the

Nervous system can be through surgical, electrical or chemical means and these are carried out

primarily on animals. The formal experimentation is carried out with strictest control of

variables. Use of human subjects is eliminated (not allowed, for ethical reasons even animal

experimentation has a strict code). This is an area which focuses on identifying variables,

creating theoretical frameworks rather than producing applied oriented results. Pure research is

a priority. It may or may not have an applied implication later.

Psychopharmacology: Earlier psychopharmacologists were also researchers in physiological

psychology; the lines were diffuse and not bifurcated. The two disciplines are still quite similar.

However, the experimentation under strict control conditions may have a different focus--one

is more interested in neural activity and interaction of drugs and the other with neural activity

and its influence on behavior. Psychopharmacology, as specialization, focuses primarily on

identifying the effects of the exogenously created substances on behavior. Pure research carried

out is on laboratory animal subjects, however, at a more advanced level of testing human

volunteers are also included in the studies,( clinical or patients suffering from the

psychopathology for which a drug has been developed), however, there are stringent procedures

for doing this kind of experimentation. The Psycho-pharmacological research can be both pure

and applied. Pure when we are testing out these substances to develop a theoretical model or

framework. As an example "SPEED" or amphetamines are abused as stimulants, chronic use

of these leads to a psychotic like state. Since amphetamines increase release of dopamine

thereby increasing its levels in the brain, this has formed basis for developing dopaminergic

Neurological Basis of Behavior (PSY - 610)

hypothesis of schizophrenia. The research in Psychopharmacology becomes APPLIED when a

drug is developed for therapeutic use in clinical setting. Many drugs being used as psychotropic

drugs were developed in the laboratories ( and are still being developed through

psychopharmacological studies). This has contributed immensely to the understanding of how

brain works with exogenous chemicals through the neurotransmitter changes.

· Comparative psychology

This is an area which is more related to biopsychology, or psychobiology, ethological, ecological,

evolutionary basis of behavior. The studies in this area can range from naturalistic studies such as

those of Konrad Lorenz, (Imprinting in birds) and Niko Tinbergen (aggression in the red stickle

back fish) and Jan Goodall (Chimpanzee studies carried out in the jungle) to laboratory

investigations, (creating a model of attachment of animals as in the case of Harlows studies on

rhesus monkeys and chimpanzees at the Wisconsin Primate Center). The focus can be micro

(where we can compare cells, parts of the brain and their functioning)- to macro and holistic (

which is extended to animal families, social and group behavior: specially studies on pheromonal

signals have carried out extensive free roaming animals social behavior studies). Some researcher

focus on the phyletic difference in behavior while others focus on higher order behaviors.

Comparative psychology studies similarities and differences in animal behaviors. Thus simply

put, it studies and compares behaviors across species and across animal kingdom.

· Neuropsychology

This is the study of behavioural deficits which result from human brain damage. The focus of area is

mainly the highly developed cerebral cortex, (neocortex) in humans. It is not possible to create

lesions or damage brain to see the aftereffects, therefore this discipline uses:

a) Case studies of patients who have suffered some damage or trauma (stroke, deficits- as an

example we have two famous cases: Phineas Gage, and H.M), to identify the relationship between

the brain areas and the functioning. These two cases will be discussed in detail in later chapters but

the case of Phineas Gage is famous as it showed that damage to the orbito-frontal area led to

personality change, and the case of HM is famous as he lost the ability to store memories after

brain surgery, he lives in short term memory.

Fig 3.1 Source : www.brown.edu/.../py47/diagrams/phineas.jpg

Fig 3.1 shows phineas gage: reconstruction from his damaged skull showed extensive damage to the

orbitofrontal cortex.

Neurological Basis of Behavior (PSY - 610)

b) Co-relational studies of damage/deficits resulting from surgery lesions. Extensive Tests are

given to identify the deficits and then these are correlated with the damage reported by the

neurologist, or surgeon or the other advanced technologies (such as MRI, PET scan etc).

In addition, the following are the areas which define neuropsychology as a speciality.

Neocortex: The focus of Neuropsychology is mainly on the neocortex, the association and other

higher order functions, but this is not necessarily true. Neuropsychologists do assess sensory motor

functioning involving the lower order brain areas as well.

Applied: Neuropsychology has a very strong applied focus, where neuropsychological assessments

are essentially done to understand the deficits- with the aim of localizing deficits to help the patient.

The aim of this discipline is to identify, provide diagnosis of the area of deficit with the specific

goal of care counseling and developing rehabilitation strategies to help the patients.

Non Invasive: This is non-invasive specialization we do not damage brains or insert tubes within

the brain to test the patient. We use tests and extrapolate functioning on the basis of performance on

the test (paper pencil, construction, memory etc).

Controls Vs Flexibility: The neuropsychological approach can vary form extremely controlled to

flexible testing. There is a strong school of thought within the discipline which believes in

flexibility of testing and assessment (especially considering that we are testing brain damaged

patients). The father of this discipline Luria (Russian Neurologist) did not believe in

standardization, but qualitative assessment and keen observation. The American school believes in

strong standardized and controlled conditions of testing and responses.

· Psychophysiology

-mStudies the relationship of physiology and behavior by recording the brain and body

electrophysiological responses both in animal and human subjects. In humans, Scalp electrodes are

placed on surface of scalp to measure electroencephalographic changes (EEG) on muscles, eye

movement, skin to measure electromyographic activity, electro-oculographic activity, and

electrodermal changes(EMG,EOG EDR). Psychophysiological measures also include autonomic

measures such as GSR, heart rate, B.P. Pupil dilation etc.

This is Non- invasive, can be applied or even pure research such as sleep research which uses EMG,

EOG and EEG recordings. We also have single cell recordings, event related potentials. Further,

electrophysiological recordings can be made of one cell or a large group of cells for an orchestrated

response.

· Cognitive neurosciences

It is the newest and most exciting, and the most active of the sciences. Cognitive neuroscience

brings together scientist from cognitive sciences (mathematicians, physicists, computer scientists

who build theoretical models) life sciences (biochemists, biologists, chemists, who actively work to

identify living tissue and functional correlates) and cognitive psychologists. It has emerged as a

distinct enterprise only recently and has been driven by methodological advances that enable the

study of the human brain safely in the laboratory. Cognition is defined as the neural basis of higher

intellectual functioning such as memory, thought, perceptions, attention, judgment, imagination,

creativity, speech and language, action, foresight and planning.

Very interesting issues are part of research in cognitive neurosciences such as how information is

stored, processed and retrieved. Is there multistage or parallel processing of information,

mathematical and computer modeling of how neural networks are formed etc.

Neurological Basis of Behavior (PSY - 610)

This is mainly non-invasive. Using techniques such as functional imaging (which measures ongoing

behavior). This is more exciting as technology develops; therefore this specialization is essentially

interdisciplinary.

In summary, all approaches work in conjunction with each other, to formulate theory and to test it.

Experiments from Physiological Psychology can be complemented by applied work in

Neuropsychology and vice-versa

Reference

Pinel, John P.J. (2003) Biopsychology (5th edition) Allyn and Bacon; Singapore

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