An Introduction to Psychology
INTRODUCTION
The study of the way people think and behave is called psychology. The field of
psychology has a number of sub-disciplines devoted to the study of the different levels
and contexts of human thought and behavior. Social psychology, for example, deals with
human thought and action in a social context, while physiological psychology is concerned
with thought and behavior at the level of neurology. Another division of psychology,
comparative psychology compares the thought and behavior of humans with that of other
species. Abnormal psychology studies atypical thought and action.
Psychology is an interdisciplinary science. Social psychology, for example, involves both
sociology and anthropology. Abnormal psychology has much in common with psychiatry, while
physiological psychology builds on the techniques and methods of neurology and
physiology.
It is evident that psychological methods are being increasingly used in daily events.
Employment for example, in Europe more companies are subjecting potential personnel to
psychological profile checks and psychological tests during interviews. Even our social
lives are becoming affected. People who are seeking the right partner are using
psychological techniques to establish the emotional state of their potential partners. As
psychology becomes more and more accessible and understandable to more people, I feel
that it will begin to influence our lifestyles more.
From a personal stand point, this has been a very difficult exercise. This is a new area
for me, so I have been unable to write from a professional or work experience perspective
only from a purely academic view.
PSYCHOLOGY.
'Psychology' literally means 'study of the mind'. Psychology as a separate discipline is
usually dated from 1879 when Wundt opened the first psychology laboratory, devoted to the
analysis of conscious thought into its basic elements, structuralism. It is understood
that 'structuralism' was founded by Wilhelm Wundt. What made this 'new' psychology
different from philosophy was the emphasis on measurement and control. The application of
some of the basic scientific method to the study of the mental process.
For psychology to become a natural science, it must confine itself to what is observable
and measurable by more than one person, namely behaviour, Behaviourism was established.
This movement was formally initiated by John Broadus Watson in a famous paper,
"Psychology as the Behaviourist Views It" published in 1913.
At the time when behaviourism was becoming prominent in America a group of German
psychologists began to discredit the principles of structuralism and behaviourism. They
argued that it was not possible to break down psychological processes. This theory,
demonstrated that our perceptions are highly organised and have immediate, vivid
qualities that cannot be explained in terms of piecing together basic elements. The
psychologists had the opinion that our perceptions are inherently configurational,
meaning that the elements making up the perception could not be separated from the way in
which those elements were combined as a whole. This now popular theory is known as
'Gestalt' taken from the German word for "configuration"
The expression of the third force movement known as "humanistic psychology" is an
eclectic grouping of American psychologists who advocated various interpretations of
human personality. The term humanistic reflects the focus on defining a human psychology
with emphases on individual existence, focusing on the role of free choice and our
ability to make rational decisions on how we live.
During the 1950s and 1960s, many psychologists began to look to the work of computer
scientists in trying to understand the more complex behaviour which, they felt, learning
theory or conditioning had oversimplified. This behaviour was referred to by early
psychologists as 'mind' or mental processes, which has become cognition or the cognitive
process. The cognitive psychologist sees the person as an information processor and
cognitive psychology , along with artificial intelligence, linguistics, philosophy,
anthropology and neuroscience now form part of cognitive science, which emerged in the
late 1970s.
How can we divide up the work that psychologists do? There is much more under the heading
of 'psychology' than the theories and principles of famous and leading psychologists of
our time. There are psychologists in all areas, specialising in a number of fields.
Physiological psychology is concerned with the neurological and physiological events that
underlie human thought and action. Some physiological psychologists are concerned with
mapping the functions of various parts of the brain. Others study both the transmission
of electrical information in the brain and the neurotransmitters that facilitate or
inhibit such transmissions. Physiological psychologists study the effects of drugs on
human behavior.
Conditioning and learning are concerned with how experience modifies thought and
behavior. Initially devoted to the investigation of principles of learning among all
species, the field now includes specific types of learning for different species. Other
areas of interest in the field include maladaptive learning, such as learned
helplessness, and learning in traditional settings such as in the classroom and on the
job.
Cognitive psychology applies to the study of thinking, concept formation, and problem
solving. Work in this field has been much influenced and aided by the use of computers.
Computers are used to present problems and tasks to subjects and to model the thinking
and problem-solving processes. The impact of computers on cognitive psychology is also
evident in the theories used to describe human thought. For example, such terms as
short-term memory and long-term memory parallel the two types of memory that are
available on computers.
Social psychology looks into all facets of human social interaction. Among the problems
studied by social psychologists are such matters as the development of friendship, the
nature of romantic attachment, and the relative effectiveness of cooperation and
competition on achievement. In recent years social psychology has included the study of
attribution. Attribution theory recognizes that psychological perceptions of events do
not always correspond to objective realities.
Abnormal psychology is the study of maladaptive behaviors. Such behaviors range from
the simple habit disorders (thumb sucking, nail biting), to the addictions (alcohol,
gambling and so on) to the most severe mental disturbances the psychoses. Abnormal
psychology investigates the causes and dynamics of mental and behavioral disorders and
tests the effectiveness of various treatments.
Vocational psychology is the study of how specific personality traits contribute to
success in different vocations. In one approach the characteristics of people already
working in a specific vocation are studied. If a personality pattern emerges, tests can
then be constructed to measure the traits and interests of people in the field. Other
individuals who exhibit the same traits and interests can be counseled to consider the
field as a possible vocational choice. Vocational psychologists also look for traits and
aptitudes that contribute to success in a vocation.
Industrial psychology concerns the physical and psychological conditions of the
workplace and how these factors contribute to an efficient work environment. Industrial
psychologists are also concerned about the design of manufactured products. Some
industrial psychologists, for example, are involved in the design of such items as
dashboards, which are used in airplanes and automobiles. Their aim is to apply a
knowledge of human capabilities and limitations to the design of instrumentation that is
to be used by humans.
Business psychology, a relatively recent branch of psychology, is the study of the
effectiveness of interpersonal relations in the workplace. Some business psychologists
set up training workshops to improve executives' management skills. They also evaluate
prospective job applicants and evaluate individuals being considered for promotion. They
employ the full range of psychological tests as well as interview procedures. Instruments
are often designed for specific types of evaluations. Experimental psychology
encompasses many different fields of psychology that employ experimental procedures.
Traditionally it has been regarded as the study of the basic sensory mechanisms: vision,
hearing, taste, touch, and smell. The classical problems of experimental psychology are
determining reaction times and reaction thresholds (the amount of stimulation needed to
produce a response for any given sense) as well as developing psychological scales for
physical stimuli, called psychophysics. Hot and cold, for example, are psychological
scalings of temperature stimuli for which such physical measures as degrees Fahrenheit
provide only physical units. Much experimental psychology today is closely tied with
physiological psychology.
Animal psychology includes several different disciplines. One is comparative
psychology, which explores animal behavior in comparison to human behavior. Comparative
psychologists, for example, might present different species with comparable tasks, to see
how their performances differ. Animal psychologists also study animals to gain insight
into human behavior. For example, the effects of drugs and tobacco on animals are
observed to determine the effects these substances have on humans.
Developmental psychology is concerned with the growth and development of individuals.
Once concerned primarily with the growth and development of children, the field has
expanded to include the growth and development of individuals throughout their lives.
Developmental psychologists explore changes associated with mental, social, and emotional
development. They also look at the evolution of friendships and parent-child
relationships. How children learn both in and outside school is another focus of
developmental research.
Clinical psychology has undergone rapid growth in recent years and is now the largest
sub-discipline within psychology. Clinical psychologists work in hospitals, in clinics,
and in private practice. Their main concerns are the diagnoses and treatment of learning
and emotional problems. Many conduct psychological research along with their applied
work.
The goal of psychology must be to further understand behaviour. This has to be done
through theories. Good psychological theories generate hypotheses about how human
behaviour should respond to given conditions. Psychology has to develop and comprehend
the behavioural attitude of not only humans but animals, and establish more relevant
theories as the science of psychology advances.
Methods of Psychology.
Psychologists use a number of research methods to study behaviour. These include surveys,
observation, case studies, correlation method and experimental methods.
Performing a survey is one of the most widely used methods of psychological research.
Representative groups are questioned either face to face or by being given formal
questionnaires to complete. There are limitations to surveys. There can easily be a bias
within the groups questioned. For example, gender, social or economic differences etc.
This can give a limited insight as to the true attitude of the group surveyed. It can
also make considerable difference as to how the questions are composed. Any question can
be written with a critical or creative style which can determine the way the person
taking part in the survey will answer. The only way to take a poll or survey is to
guarantee that the individuals surveyed (a sample) will be representative of the whole
group you are interested in. In a random sample, every individual in the population has
an equal chance to be in the sample.
Observational research methods can either be in a controlled environment or subjects can
be observed in their normal day to day habitat, known as naturalistic observation. The
most critical feature of naturalistic observation is that 'the act of observing someone
must not interfere with how the person behaves'. When people know they are being watched
, they are likely to try and look as good as they can. The advantage of naturalistic
observations is that they are made under real life conditions. The main disadvantage is
that we can seldom say with certainty why people behaved as they did because we do not
have any control over the circumstances in which they were behaving.
Most data-gathering procedures in psychology collect a limited amount of information from
a large number of people, the aim of a case study is to obtain large amounts of
information about an individual or small group. Detail of this kind can help the
psychologist understand complex relationships and behavioral patterns. Among the
disadvantages of case studies is the potential for observer bias and the lack of proper
sampling opportunities.
A list of facts and figures of the kind that may be obtained from any of the previous
research methods can only provide a limited insight into the nature of behaviour. A
useful strategy is to look for relationships among the various measures obtained. Studies
with this purpose are described as correlational. Correlational studies may use a number
of different research methods to obtain the data. The distinctive feature of a
correlational study is not the method used to gather the data but the questions the data
is designed to answer.
The difficulty with correlational studies is not that they fail to suggest causal
relations but that they suggest too many. The experiment is the only method by which
science can establish causal relations. In experimental research the conditions under
which observations are made are arranged so the number of possible causes can be
controlled and specified. All experiments have one or more independent and dependent
variables. The independent variable is the set of conditions established by the
experiment. The dependent variable is that aspect of the subjects' behaviour measured by
the experimenter and which could possibly be influenced by the independent variable.
Naturally the limitation of any experimental research is the artificial surroundings in
which they are performed.
Psychology makes extensive use of statistics. These methods have two broad functions in
the analysis of data: descriptive and inferential. The aim of descriptive methods is to
provide a summary of data so that important features are more readily apparent.
Inferential methods are used to evaluate the extent to which data supports a hypotheses
or can be generalised beyond the particular study being analysed.
The controlling influence over all of these research methods is of course ethics. Ethics
considerations arise with both human and animal subjects. To help researchers, as well as
safeguard the welfare of the subjects, ethical guidelines exist in many countries.
THE NERVOUS SYSTEM.
The nervous system of humans and other vertebrates consists of two major parts: the
central nervous system (CNS) and the peripheral nervous system (PNS)
The CNS consists of the brain and the spinal cord. It occupies the commanding position in
the nervous system, as it coordinates and integrates all bodily functions.
The PNS, which transmits messages to and from the CNS. has two divisions: somatic
and autonomic. Autonomic nerves are motor nerves only. They regulate a great variety of
bodily functions.
Cerebral Cortex.
The very elaborate cerebral cortex is layered sheet some 2.5mm thick of literally
billions of nerve cells that go over and around the brain. It covers the upper and outer
portions of the brain called the cerebrum. This is why it is called the cerebral cortex.
The cortex is wrinkled and folded. This convoluting greatly enlarges the surface area
available, compared to a similarly sized smooth cortex.
The cerebrum is divided down the middle from front to back into two halves: the right and
the left cerebral hemispheres. Each hemisphere controls the activities of the opposite
side of the body that is, the left cerebral hemisphere controls the right side of the
body and the right hemisphere controls the left side. Although in many ways the two
hemispheres are mirror images of one another, there are functional distinctions between
them. In most people, the areas that control the development and use of language are
located in the left hemisphere, while areas that govern three-dimensional visualization
and musical and artistic creation are located in the right hemisphere.
Each hemisphere of the cerebrum is divided into four sections: the frontal, parietal (top
rear), temporal (lower), and occipital (rear) lobes. The back part of the frontal lobe
contains areas that govern movement of the opposite side of the body. Damage to this
region results in paralysis. In front of this region is an area of the frontal lobe
called the premotor cortex, where complex movements are controlled. Still farther forward
is the prefrontal cortex, which exerts an inhibitory control over actions. Such
distinctly human abilities as foreseeing the consequences of an action, exercising
self-restraint, and developing moral and ethical standards depend on the normal
functioning of the prefrontal cortex. The parietal lobe, the part of the hemisphere that
lies behind the frontal lobe, contains the primary sensory cortex the part of the brain.
It receives sensory information from the opposite side of the body. Below the frontal and
parietal lobes is the temporal lobe, which is involved with hearing and memory. Behind
the temporal lobe is the occipital lobe, the visual center of the brain. Here the signals
that come to the brain from the eyes are put through very complex transformations in a
process of analysis and integration.
Cranial nerves are a group of 12 pairs of sensory, motor, or mixed (having separate
sensory and motor fibers) nerves that connect with the brain stem and the lower parts of
the brain.
The Endocrine System.
Endocrine glands secrete onto adjacent tissue where the hormone is picked up by the
blood, lymph system, or nerve cells and transported to the target organ. The adrenals,
thyroid, parathyroid, pituitary, hypothalamus, pineal, and ovary are endocrine glands.
The secretions of endocrine glands are called hormones. Mixed exocrine and endocrine
glands, which secrete in both ways, include the liver, testes, and pancreas. Endocrine
glands release extremely small amounts because hormones are powerful substances. The
activities of the endocrine glands form one of the most complex systems in the body.
Although each gland has its own unique function, the glands are interdependent, and the
function of one depends on the activity of another. The hypothalamus produces several
hormones, including those that regulate pituitary activity. The pituitary produces its
own hormones that regulate growth and stimulate other endocrine glands. The adrenals,
thyroid, testes, and ovaries are dependent upon pituitary stimulation. The hormones these
glands produce govern metabolism, blood pressure, water and mineral balance, and
reproductive functions, and they help defend against injury. The term hormone is
derived from a Greek word meaning 'stir up'.
Drugs Affecting Behaviour.
Many kinds of drugs are prescribed for anxiety, sleeping and nervous disorders. Several
types of sedative drugs induce sleep and cause intoxication. These drugs although
prescribed for sleep disorders and anxiety problems, can also cause physical and
psychological dependence. These include ethyl alcohol, barbiturates, methaqualone, and
many others.
There are of course everyday drugs that are consumed in enormous quantities by millions
of people. Caffeine, nicotine and alcohol are used daily by a large number of people, to
the extent where they could be classed as addictive. Alcohol addiction is by far one of
the most common addictions globally. While there appears to be little evidence that using
alcohol in moderation does any damage, but excessive drinking is a major problem in many
countries causing many man hours of lost work, social and domestic violence problems.
Repeated heavy drinking can cause serious medical problems, liver damage and irreversible
brain damage in some cases.
SENSORY PROCESSES.
The term sensation refers to the process of receiving information in the form of energy
(light, heat, sound etc.) from the world outside and sorting it out into the proper sense
- vision, touch, hearing. Once that information has been received, we interpret it and
arrive at an understanding of what it means, a process referred to as perception.
Sensation and perception make up an extensive information gathering system.
Each sense has it's own receptors that constantly monitor our environment. All sensory
systems have certain characteristics: The sensory system must be selective, which means
that only certain types of incoming information are processed. For example, we have more
than one kind of receiver for touch. One which responds to changes in temperature and one
which responds to damaged cells. The sensory system must have an adjustable speed. Nerve
fibres to the ear respond in less than a thousandth of a second because sudden noise does
not require analysis, as it does a speedy response. However, the visual system will
respond quickly to a blur as something comes towards us, a potential danger, yet it will
take it's time when analyzing a complex scene. The system must also be sensitive, but
not too much. If our ears were too sensitive we would hear blood running through artery
at the base of the ear. Sensory measurement must be reliable. Reliability comes from
comparing incoming stimulus with the conditions around us.
Vision.
The optic nerve delivers its impulses to a special area of the brain called the visual
center . This is where people "see" objects in the sense of recognizing and reacting to
what their eyes look at. In other words, seeing always involves the brain's visual
center. Here sensation turns into perception.
The brain must learn by experience to analyze correctly the impulses it receives from the
eyes. For instance, the lens system of the eye, like that of a camera, transmits its
light pattern upside down. The brain has to learn that the impulses received from the
upper part of the retina represent the lower part of the object sighted and vice versa.
In the brain also are located the centers that control all the eye's muscular movements,
such as the opening and closing of the iris, the focusing of the main lens, and the
movement of the eyeball. The eyeball's movement is voluntary. Other eye adjustments are
reflexes. Most individuals use both eyes to see an object. This type of sensory
perception is known as binocular vision. Thus two images of the object are formed one on
the retina of each eye. Impulses from both images are sent to the brain. Through
experience these impulses are interpreted as two views of the same object. Because the
eyes are about 2 inches apart from pupil to pupil and therefore are looking at the
object from different angles, the two views are not exactly alike. This is known as the
stereoscopic effect. If the object is far away, the difference between the images is
slight. If it is a few inches away, the difference is very great. The brain makes good
use of this phenomenon. It learns to judge the distance of an object by the degree of
difference between the images it receives from the two eyes. In the same way the brain
perceives what is called perspective.
The Eye.
The retina is a soft, transparent layer of nervous tissue made up of millions of light
receptors. The retina is connected to the brain by the optic nerve. All of the structures
needed to focus light onto the retina and to nourish it are housed in the eye, which is
primarily a supporting shell for the retina. When light enters the eye it passes through
the lens and focuses an image onto the retina. The retina has several layers, one of
which contains special cells named for their shapes rods and cones. Light-sensitive
chemicals in the rods and cones react to specific wavelengths of light and trigger nerve
impulses. These impulses are carried through the optic nerve to the visual center in the
brain. Here they are interpreted, and sight occurs. Light must pass through the covering
layers of the retina to reach the layer of rods and cones. There are about 75 to 150
million rods and about 7 million cones in the human retina. Rods do not detect lines,
points, or color. They perceive only light and dark tones in an image. The sensitive rods
can distinguish outlines or silhouettes of objects in almost complete darkness. They make
it possible for people to see in darkness or at night. Cones are the keenest of the
retina's receptor cells.
Hearing.
In hearing the basic energy form is sound waves. Sound waves form at various speeds, or
frequencies. The frequency of any given tone is measured in terms of the number of cycles
per second. Sound travels slowly compared to light at anything from 20-20,000 cycles per
second. The sounds we hear have three basic characteristics. Pitch, which is the
frequency of the sound. Timbre, determines the tonal quality . The loudness or intensity
of the sound wave is measured in decibels. The human ear can pick up sounds just above
'0' decibels, otherwise there would be complete silence.
Decibel Table.
Decibels Noise Threshold
40 Quiet office Normal
60 Normal conservation Normal
75 Road Traffic Noisy
100 Subway Train Potential Damage
130 Rock Concert Human Pain Threshold
140 Aircraft Taking-off Human Pain Threshold
The Structure of the Ear.
The ear has three separate sections the outer ear, the middle ear, and the inner ear.
Each section performs a specific function, related to either hearing or balance. The
three parts of the outer ear are the auricle (also called the pinna), the external
auditory meatus (or ear canal), and the tympanic membrane (or eardrum). The pinna
collects sound waves from the air. It funnels them into a tube, the external auditory
meatus. This is a curved corridor that leads to the tympanic membrane. The eardrum
separates the external ear from the middle ear. The middle ear is an irregular-shaped,
air-filled space. A link of three tiny bones, the ossicles, spans the middle ear. When
sound waves strike the outer surface of the eardrum, it vibrates. These vibrations are
mechanically transmitted through the middle ear by the ossicles, to the opening. This
opening is the round window. Like the eardrum, the round window's membrane transmits
vibrations. It directs vibrations into the inner ear, where they enter a fluid that fills
a structure called the cochlea. This is a coiled tube that resembles a snail's shell.
Within the cochlea is housed the true mechanism of hearing, called the organ of Corti. It
contains tiny hair-like nerve endings anchored in a basilar membrane, which extends
throughout the cochlea. The unattached tips of these nerve endings are in contact with an
overhanging membrane, called the tectorial membrane. When vibrations pass into the inner
ear, they cause waves to form in the cochlear fluid. Receptor nerve cells in the organ of
Corti are highly sensitive to these waves. Other specialized nerve cells send the
electrochemical impulses produced by the wave motion into the cochlear branch of the
acoustic nerve. This nerve carries the impulses to the brain, where sound is identified.
Taste.
It is widely accepted that there are four basic taste qualities, salty, sour, sweet and
bitter. It was originally thought that there was a sensory path for each of these tastes.
However it appears that there is a pattern of activation in a number of different fibres
providing the required sensory input to the brain to distinguish these different tastes.
The papillae on the surface of the tongue are the receptors for these taste sensations.
Smell.
Deciphering the sensory information for the sense of smell is not dissimilar to that of
taste. In the olfactory area the nerve endings grow through the mucous membrane which act
as receptors to determine odors present in the air we breathe.
Touch.
The skin or cutaneous sense has some 5 million sensors of at least 7 types throughout
the human body. The three major types are Meissner's corpuscles which sense touch. The
Pacinian corpuscle's which determine movement and vibration and the Krause end bulbs
which sense changes in temperature.
Equilibrium and Proprioception.
Proprioception (kinesthesia), establishes the position of limbs and underlies the
ability to assume and maintain posture, to move about in the environment, to manipulate
objects and to be coordinated. These senses did not figure prominently in the traditional
account of senses because they have no external sources of adequate stimulation. They do
have identifiable and understood sensory receptors. Both play an important role in
maintaining posture and balance.
PERCEPTION.
Perception is the primary process by which we obtain knowledge about the world. It
involves the activity of our senses in responding to external stimulation. Perception is
a skill or set of skills, not simply the passive reception of external stimulation. The
process of structuring these stimuli into objects we can perceive is called perceptual
organisation. There are a number of principles to perceptual organisation.
Figure and Ground.
Gestalt psychologists identified the tendency to differentiate between figure and
ground. The figure being the part of an image which we notice prominently, opposed to the
background, the ground. This theory not only applies to visual items, but
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