INTRODUCTION:Descriptive, Experimental and/ or Natural Studies

BRIEF HISTORICAL REVIEW:Roots of Behavioural Neurosciences >>

Neurological Basis of Behavior (PSY - 610)

Lesson 01

INTRODUCTION

Objectives:

· To familiarize the students with study of brain behavior study.

· To orient them towards its historical and scientific roots.

· To relate it to other areas of specialization in Psychology.

Introduction

The mastermind of all our living being is the brain which controls every aspect of behavior from molar

to molecular--a universe within the small cranium. Millions of neurons and glial cells interaction, firing

constantly resulting in the gross behaviors we see or experience.

Pinel (2002) defines Biopsychology (also known as psychobiology, behavioral biology, behavioural

neurosciences) as the scientific study of biology of behavior.

Carlson (2005) calls it the physiology of behavior where the brain and physiological correlates and

modulators of behavior are the domain of study.

We put together a definition encompassing these and simply state that "Behavioural Neurosciences

aims to study brain-behavior relationships utilizing all its specializations and methodologies"

Basic questions in the study of brain and behavior

There are several basic questions in the study of brain and behavior which are part of a continuing and

recurrent discussion,

· Is brain's relationship with behavior controlled by nature or nurture, is it genes or environment?

· Where did the study of the brain start (and who are the major contributors, how far do we go)?

· How does the brain know what to process, where and what about (people, places, objects)?

· How does the brain grow (evolutionary and developmental perspective)?

· What and where are the controls of our motivated behaviors?

· Why do we remember (smells, visuals, kinesthetic) and how do we retrieve these memories? Why

do we forget, what can go wrong (Alzheimer's)?

· Where does pleasure, pain, happiness addiction happen in the brain?

· What are neurochemicals, what are the various electrical, electro-physiological, neurochemical,

biochemical, and other changes that take place in the brain, which molecules go where and do

what?

· What happens if the systems malfunction, does one affect the rest, or things go on as before?

· What happens after brain damage- do we reconstruct?

· Why is it important for psychologists to know about the brain?

These are the questions which make the study of brain so exciting, and many questions are answered,

which raise more questions! Research is ongoing throughout the 24 hours somewhere around the world.

Neuroscientists are working around the clock and discoveries are being made, explanations offered

theories formed or rejected.

There are many ways of looking at the brain behavior interactions:

Neurological Basis of Behavior (PSY - 610)

Descriptive: To study behavior and brain functioning as it occurs without interfering in the

ongoing processes. This gives one a perspective of how behavior would occur under natural

circumstances.

Comparative, evolutionary perspective: This is used to see when researchers are looking for

continuity among species as well as why and how changes in brain and behaviors have evolved

and what do they lead to. Further this also answers many questions raised about behaviors

which can be partially answered by studying animals. Are evolutionary changes ongoing

processes? Also if there are any species specific behaviors which are found in other species and

the homosapien (human).

Developmental (over life span). How does the brain grow from the time of fertilization to

maturity, aging and death? What are various developmental stages? The question keeps arising

over and over again whether nature or nurture triggers or controls it, whether it is biological and

genetic programming or external stimulation which moves development in a particular

direction. Where can things go wrong or where does the environment and nature interact. How

many degrees of freedom for either to act and when?

Experimental and/ or Natural Studies

The continuum of research and investigation extends from the naturalistic ethological studies i.e. from

Joan Goodalls chimpanzee studies and Konrad Lorenz's earlier investigation to experimental/ laboratory

studies to brain manipulation studies.

Molar and molecular

The level of studies on analysis within the brain varies from studying behavior of a large number of

neurons or just one under the microscope. The Molar view focuses on groups of networks, neurons or

neuroantomical areas whereas the Molecular investigation focuses on single units, single cell, single

molecule, single impulse and the brain behavior relationships.

In addition to the above there are many areas which form part of neuroscientific study i.e.

neurohormonal influences on growth, development and subsequent expression and modulation of

behavior, the role of sleep, dreams and how the brain controls these are also important in understanding

brain behavior relationships. Behavioral neurosciences studies the brain-behavior relationship from a

wide range of perspectives and specializations.

Range of Behaviors:

Areas in brain/behavior relationships which have been

studied and researched range from simpler to complex

behaviors, as they form part of human and animal

behavioral repertoire.

Some of the simpler behaviors (as they can be measured as

activity is ongoing and the neurochemical interactions,

neuroantomical substrates are fairly well identified) are

feeding, thirst, sexual behavior, temperature regulation

aggression

etc.

Similarly,

neuroantomical

and

neurochemical substrates of vision, perception, audition,

movement of body parts are also fairly well defined by

research carried out so far.

However, complex behaviors are of special interest. We are

Fig.1.1 Cerebral Hemispheres

intrigued by the brain mechanisms of memory, learning and

forgetting (why do we have different types of learning and /or memories), attachment, addiction,

emotional states (anger, fear) etc.

Neurological Basis of Behavior (PSY - 610)

There are even more complex behaviors such as brain hemispheric functioning of the cerebral cortex

and these become more interesting as new technologies such as MRI emerge which pose challenges to

scientists. Further more, Depression, Schizophrenia are far more complex and are not easily

investigated.

Neurosciences:

The most interesting area has grown rapidly in the last century. The 21st century is the century of the

brain. In the middle of the 1970's a brain scientist, Valenstein wrote a book "Brain Control" predicting

possibilities emanating from the study of the brain. Researchers investigate how behavior is related to

neuroanatomical localizations, neurochemicals and how behavior can be controlled with the

manipulations of these as well as drugs and external "controls".

The most interesting aspect of this area is the intricacy and interdependence of brain-behavior

relationship and connections. It is most fascinating to discover how the brain masterminds behaviors of

organisms. This is the Pandora's Box, the more we know the more questions emerge and the more we

realize we don't know enough, i.e. the less we know. Researchers and fields have multiplied incredibly

from the 60's in the last century and research is ongoing 24 hours of the day around the clock in labs

around the globe. So much so that Behavioural Neurosciences has emerged as a discipline where

boundaries between chemistry, biochemistry, ethology, physiology, neuroanatomy, pharmacology,

psychology, neurobiology and even neurophysics have melted and merged into one discipline while

spawning others.

Issues in Neurosciences:

This discipline has many issues, some of which we have discussed earlier, however, we must remember

it is not easy to study the brain, and there are many views of how the brain functions. We can generally

categorize viewpoints regarding the brain functioning as follows:

1. Localization vs. Equipotentiality:

Among the major issues investigated in Behavioural Neurosciences is the localization of functions. Is it

one area or a group of areas working together (you need to see or feel or estimate distances when

walking), how do they "talk to each other and who listens to whom". Are functions and neuroanatomical

areas localized (specialized) or equipotential (all areas have similar capabilities) or is it a combination of

both.

2. Nature vs. Nurture:

The eternal nature-nurture debate continues in this discipline, i.e. whether the behaviors such as

Schizophrenia have a genetic, biochemical basis or are the behaviors environmentally influenced.

Related to this is the major issue of development of the brain. Does the brain during development,

accept environmental influences or is it preprogrammed to develop in a predetermined manner.

Findings have shown that both nature and nurture play a very important role in the development.

At present the Behavioural Neuroscientists are wiser and do not take up such controversial either/or

positions It appears that genes or environment do not act alone, so nature provides the template on

which the environment can act. Behaviors are not categorized simplistically as one or the other; they are

resultants of complex interactions of both. Research in future may be able to pinpoint exactly how much

each contributes to the development of behaviors. Till such time it would be appropriate to

remember that both have important roles to play in the appearance, development, growth and

expression of behaviors.

3) Molar level vs. Molecular level:

The scope of behaviors studied in the neurosciences vary from microscopic to holistic levels,

Micro-(reductionism as it reduces behavior to its cellular component) to macro ( holistic and more as a

total than sub components). The behaviours studied under the micro level could be that of a cell, or

components within a cell, its electrophysiological functioning, its ionic movements etc. Whereas macro

Neurological Basis of Behavior (PSY - 610)

could be a group of cells, or neurochemical pathways or behaviors emanating out of neuroanatomical

location or even behaviours of a species.

Behavioural neuroscientists now use both methods in combination (Can do observations in lab using

open field technique and experimental methods in open ranging animals implant electrodes to study

natural behavior).

Behavioural Neurosciences thus is as wide as the fields within the scope of its domain and every single

aspect of brain/behaviour relationship of any organisms comes under its preview. This has extended

more recently to a point where disciplines such as neurophysics have emerged, and mathematical

modeling of neural connectivity and communication as well as computer simulation of complex

experiences (and neural networks) is very much part of robotics.

Historical Roots of Brain Sciences:

· Hippocrates stated that the brain was the seat and center of sensation, thought, emotions and

judgment.

Muslim contribution is the first recorded brain dissection with anatomical details were given by

Muslim scientists. This is experimental as well as descriptive (not speculative work). While

dissecting, they discovered the hard protective covering protecting the brain and named it as Umm

ul Dafah (hard protective covering) and the inner covering also the fragile mother. These were

translated verbatim into Latin during the renaissance as Dura Mater and Pia Mater (Mater from

Umm mother, protective covering).

Franz Gall presented the concept of phrenology where faculties were located in centers of the

brain. The bumps on the cranium were also part of his formal theory. However, he also presented

the concept that the two hemispheres were joined by corpus callosum.

Around 1800's, Flourens was the first one to experiment with ablation of avian brains. He

demonstrated loss of function with damage. He proposed the concept of equipotentiality of the

brain on the basis of his investigations.

In 1861, Paul Broca presented evidence for speech expression in specific brain areas, i.e. frontal

motor areas for speech. This area is formally known as the Broca's area now.

In1868, Hughlins Jackson presented the idea of differentiation of two types of language

functions- expressive and receptive, he also elaborated on a particular form of epilepsy known as

the Jacksonian seizure.

In late 1800's Wernicke's presented evidence for control of receptive speech in temporal lobe.

This area is now known as the Wernicke's area.

Many eminent names followed up on brain research some of those who got Nobel prizes are

Gazzaniga, Sperry for their work in the 1960's. Lashley and Hebb are known as the fathers of

Behavioural Neurosciences as we know it today.

Roots of Behavioural Neurosciences

Basically the roots of experimentation in psychology emerge from adaptation of methods of Physics.

The well known psychophysical methods were developed by Weber who experimented on relationships

of stimulus and responses. Relating experiences to the brain has its origins in the work of William

James, Karl Lashley, Sherrington and Pavlov. To put forward the view that biological functions and

experiences are related to the brain two names stand out, that of Lashley and Pavlov. If we look at the

following continuum we see the range of work, areas and eminent names under each category.

Neurological Basis of Behavior (PSY - 610)

Areas:

Brain------------------- -experimentation------------------natural study

Specialization: Neurophysiology----------Psychophysics---------------------Ethology

Names

:Sherrington............Weber,Fechner....................Darwinian

Lashley.....................Helmholtz........................Niko Tinbergen

James.....................Young...........................Konrad Lorenz

Experimentalists believe that uncontrolled observation is nonscientific; there are too many uncontrolled

variables in behaviors for us to draw any conclusions.

References:

1. Kalat J.W (1998) Biological Psychology Brooks/ Cole Publishing

2. Carlson N.R. (2005) Foundations of Physiological Psychology Allyn and Bacon, Boston

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

4 Bloom F, Nelson and Lazerson (2001), Behavioral Neuroscience: Brain, Mind and Behaviors (3rd

edition) Worth Publishers New York

5. Bridgeman, B (1988) The Biology of Behaviour and Mind. John Wiley and Sons New York

6. Seigel, G.J. (Ed. in chief) Agranoff, B.W, Albers W.R. and Molinoff, P.B. (Eds) Basic

Neurochemistry: Molecular, Cellular and Medical Aspects

Source

the

image

cerebral

hemisphere

was

taken

from

the

site

www.cwx.prenhall.com/.../medialib/images/F02_11.jpg

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