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:

  • 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 intrigued by the brain mechanisms of memory, learning and forgetting (why

neurological basis of behavior  INTRODUCTION:

do we have different types of learning and /or memories), attachment, addiction, emotional states (anger, fear) etc.

Fig.1.1 Cerebral Hemispheres

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 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.

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
  4. Bridgeman,B (1988)The Biology of Behaviour and Mind. John Wiley and Sons New York
  5. Seigel,G.J. ( Ed. in chief) Agranoff, B.W, Albers W.R. and Molinoff, P.B. (Eds) Basic Neurochemistry: Molecular, Cellular and Medical Aspects
  6. Source of the image of cerebral hemisphere was taken from the site www.cwx.prenhall.com/…/medialib/images/F02_11.jpg
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