PsychologyINTRODUCTIONThe study of the way people think and behave is called psychology. Thefield of psychology has a number of sub-disciplines devoted to the study of thedifferent levels and contexts of human thought and behavior. Social psychology,for example, deals with human thought and action in a social context, whilephysiological psychology is concerned with thought and behavior at the level ofneurology. Another division of psychology, comparative psychology compares thethought and behavior of humans with that of other species. Abnormal psychologystudies atypical thought and action.
Psychology is an interdisciplinary science. Social psychology, forexample, involves both sociology and anthropology. Abnormal psychology has muchin common with psychiatry, while physiological psychology builds on thetechniques and methods of neurology and physiology.It is evident that psychological methods are being increasingly used indaily events. Employment for example, in Europe more companies are subjectingpotential personnel to psychological profile checks and psychological testsduring interviews. Even our social lives are becoming affected. People who areseeking the right partner are using psychological techniques to establish theemotional state of their potential partners.
As psychology becomes more and moreaccessible and understandable to more people, I feel that it will begin toinfluence 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 orwork experience perspective only from a purely academic view.PSYCHOLOGY.’Psychology’ literally means ‘study of the mind’. Psychology as aseparate discipline is usually dated from 1879 when Wundt opened the firstpsychology laboratory, devoted to the analysis of conscious thought into itsbasic elements, structuralism. It is understood that ‘structuralism’ wasfounded by Wilhelm Wundt.
What made this ‘new’ psychology different fromphilosophy was the emphasis on measurement and control. The application of someof the basic scientific method to the study of the mental process.For psychology to become a natural science, it must confine itself towhat is observable and measurable by more than one person, namely behaviour,Behaviourism was established. This movement was formally initiated by JohnBroadus 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 groupof German psychologists began to discredit the principles of structuralism andbehaviourism. They argued that it was not possible to break down psychologicalprocesses. This theory, demonstrated that our perceptions are highly organisedand have immediate, vivid qualities that cannot be explained in terms of piecingtogether basic elements. The psychologists had the opinion that our perceptionsare inherently configurational, meaning that the elements making up theperception could not be separated from the way in which those elements werecombined as a whole. This now popular theory is known as ‘Gestalt’ taken fromthe German word for “configuration”The expression of the third force movement known as “humanisticpsychology” is an eclectic grouping of American psychologists who advocatedvarious interpretations of human personality. The term humanistic reflects thefocus on defining a human psychology with emphases on individual existence,focusing on the role of free choice and our ability to make rational decisionson how we live.
During the 1950s and 1960s, many psychologists began to look to the workof computer scientists in trying to understand the more complex behaviour which,they felt, learning theory or conditioning had oversimplified. This behaviourwas referred to by early psychologists as ‘mind’ or mental processes, which hasbecome cognition or the cognitive process. The cognitive psychologist sees theperson as an information processor and cognitive psychology , along withartificial intelligence, linguistics, philosophy, anthropology and neurosciencenow form part of cognitive science, which emerged in the late 1970s.How can we divide up the work that psychologists do? There is much moreunder the heading of ‘psychology’ than the theories and principles of famousand leading psychologists of our time. There are psychologists in all areas,specialising in a number of fields.
Physiological psychology is concerned with the neurological andphysiological events that underlie human thought and action. Some physiologicalpsychologists are concerned with mapping the functions of various parts of thebrain. Others study both the transmission of electrical information in the brainand 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 modifiesthought and behavior. Initially devoted to the investigation of principles oflearning among all species, the field now includes specific types of learningfor different species. Other areas of interest in the field include maladaptivelearning, such as learned helplessness, and learning in traditional settingssuch 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 bythe use of computers. Computers are used to present problems and tasks tosubjects and to model the thinking and problem-solving processes. The impact ofcomputers on cognitive psychology is also evident in the theories used todescribe 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 thedevelopment of friendship, the nature of romantic attachment, and the relativeeffectiveness of cooperation and competition on achievement. In recent yearssocial psychology has included the study of attribution. Attribution theoryrecognizes that psychological perceptions of events do not always correspond toobjective realities.Abnormal psychology is the study of maladaptive behaviors. Suchbehaviors range from the simple habit disorders (thumb sucking, nail biting), tothe addictions (alcohol, gambling and so on) to the most severe mentaldisturbances the psychoses.
Abnormal psychology investigates the causes anddynamics of mental and behavioral disorders and tests the effectiveness ofvarious treatments.Vocational psychology is the study of how specific personality traitscontribute to success in different vocations. In one approach thecharacteristics of people already working in a specific vocation are studied.
Ifa personality pattern emerges, tests can then be constructed to measure thetraits and interests of people in the field. Other individuals who exhibit thesame traits and interests can be counseled to consider the field as a possiblevocational choice. Vocational psychologists also look for traits and aptitudesthat contribute to success in a vocation.Industrial psychology concerns the physical and psychological conditionsof the workplace and how these factors contribute to an efficient workenvironment. Industrial psychologists are also concerned about the design ofmanufactured products.
Some industrial psychologists, for example, are involvedin the design of such items as dashboards, which are used in airplanes andautomobiles. Their aim is to apply a knowledge of human capabilities andlimitations to the design of instrumentation that is to be used by humans.Business psychology, a relatively recent branch of psychology, is thestudy of the effectiveness of interpersonal relations in the workplace. Somebusiness psychologists set up training workshops to improve executives’management skills. They also evaluate prospective job applicants and evaluateindividuals being considered for promotion. They employ the full range ofpsychological tests as well as interview procedures. Instruments are oftendesigned for specific types of evaluations.
Experimental psychologyencompasses many different fields of psychology that employ experimentalprocedures. Traditionally it has been regarded as the study of the basic sensorymechanisms: vision, hearing, taste, touch, and smell. The classical problems ofexperimental psychology are determining reaction times and reaction thresholds(the amount of stimulation needed to produce a response for any given sense) aswell as developing psychological scales for physical stimuli, calledpsychophysics. Hot and cold, fo r example, are psychological scalings oftemperature stimuli for which such physical measures as degrees Fahrenheitprovide only physical units. Much experimental psychology today is closely tiedwith physiological psychology.Animal psychology includes several different disciplines.
One iscomparative psychology, which explores animal behavior in comparison to humanbehavior. Comparative psychologists, for example, might present differentspecies with comparable tasks, to see how their performances differ. Animalpsychologists also study animals to gain insight into human behavior.
Forexample, the effects of drugs and tobacco on animals are observed to determinethe effects these substances have on humans.Developmental psychology is concerned with the growth and development ofindividuals. Once concerned primarily with the growth and development ofchildren, the field has expanded to include the growth and development ofindividuals throughout their lives.
Developmental psychologists explore changesassociated with mental, social, and emotional development. They also look at theevolution of friendships and parent-child relationships. How children learn bothin and outside school is another focus of developmental research.
Clinical psychology has undergone rapid growth in recent years and isnow the largest sub-discipline within psychology. Clinical psychologists work inhospitals, in clinics, and in private practice. Their main concerns are thediagnoses and treatment of learning and emotional problems. Many conductpsychological research along with their applied work.The goal of psychology must be to further understand behaviour. This hasto be done through theories. Good psychological theories generate hypothesesabout how human behaviour should respond to given conditions.
Psychology has todevelop 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.
Theseinclude surveys, observation, case studies, correlation method and experimentalmethods.Performing a survey is one of the most widely used methods ofpsychological research. Representative groups are questioned either face to faceor by being given formal questionnaires to complete. There are limitations tosurveys. There can easily be a bias within the groups questioned. For example,gender, social or economic differences etc. This can give a limited insight asto the true attitude of the group surveyed.
It can also make considerabledifference as to how the questions are composed. Any question can be writtenwith a critical or creative style which can determine the way the person takingpart in the survey will answer. The only way to take a poll or survey is toguarantee that the individuals surveyed (a sample) will be representative of thewhole group you are interested in. In a random sample, every individual in thepopulation has an equal chance to be in the sample.Observational research methods can either be in a controlled environmentor subjects can be observed in their normal day to day habitat, known asnaturalistic observation. The most critical feature of naturalistic observationis that ‘the act of observing someone must not interfere with how the personbehaves’. When people know they are being watched , they are likely to try andlook as good as they can.
The advantage of naturalistic observations is thatthey are made under real life conditions. The main disadvantage is that we canseldom say with certainty why people behaved as they did because we do not haveany control over the circumstances in which they were behaving.Most data-gathering procedures in psychology collect a limited amount ofinformation from a large number of people, the aim of a case study is to obtainlarge amounts of information about an individual or small group. Detail of thiskind can help the psychologist understand complex relationships and behavioralpatterns. Among the disadvantages of case studies is the potential for observerbias and the lack of proper sampling opportunities.A list of facts and figures of the kind that may be obtained from any ofthe previous research methods can only provide a limited insight into the natureof behaviour. A useful strategy is to look for relationships among the variousmeasures obtained.
Studies with this purpose are described as correlational.Correlational studies may use a number of different research methods to obtainthe data. The distinctive feature of a correlational study is not the methodused to gather the data but the questions the data is designed to answer.The difficulty with correlational studies is not that they fail tosuggest causal relations but that they suggest too many.
The experiment is theonly method by which science can establish causal relations. In experimentalresearch the conditions under which observations are made are arranged so thenumber of possible causes can be controlled and specified. All experiments haveone or more independent and dependent variables. The independent variable is theset of conditions established by the experiment. The dependent variable is thataspect of the subjects’ behaviour measured by the experimenter and which couldpossibly be influenced by the independent variable. Naturally the limitation ofany experimental research is the artificial surroundings in which they areperformed.Psychology makes extensive use of statistics.
These methods have twobroad functions in the analysis of data: descriptive and inferential. The aim ofdescriptive methods is to provide a summary of data so that important featuresare more readily apparent. Inferential methods are used to evaluate the extentto which data supports a hypotheses or can be generalised beyond the particularstudy being analysed.The controlling influence over all of these research methods is ofcourse ethics. Ethics considerations arise with both human and animal subjects.To help researchers, as well as safeguard the welfare of the subjects, ethicalguidelines exist in many countries.THE NERVOUS SYSTEM.
The nervous system of humans and other vertebrates consists of two majorparts: the central nervous system (CNS) and the peripheral nervous system (PNS)The CNS consists of the brain and the spinal cord. It occupies thecommanding position in the nervous system, as it coordinates and integrates allbodily functions.The PNS, which transmits messages to and from the CNS. has twodivisions: somatic and autonomic. Autonomic nerves are motor nerves only.
Theyregulate a great variety of bodily functions.Cerebral Cortex.The very elaborate cerebral cortex is layered sheet some 2.5mm thick ofliterally billions of nerve cells that go over and around the brain. It coversthe upper and outer portions of the brain called the cerebrum. This is why itis called the cerebral cortex. The cortex is wrinkled and folded.
Thisconvoluting greatly enlarges the surface area available, compared to a similarlysized smooth cortex.The cerebrum is divided down the middle from front to back into twohalves: the right and the left cerebral hemispheres. Each hemisphere controlsthe activities of the opposite side of the body that is, the left cerebralhemisphere controls the right side of the body and the right hemisphere controlsthe left side. Although in many ways the two hemispheres are mirror images ofone another, there are functional distinctions between them. In most people, theareas that control the development and use of language are located in the lefthemisphere, while areas that govern three-dimensional visualization and musicaland artistic creation are located in the right hemisphere.
Each hemisphere of the cerebrum is divided into four sections: thefrontal, parietal (top rear), temporal (lower), and occipital (rear) lobes. Theback part of the frontal lobe contains areas that govern movement of theopposite side of the body. Damage to this region results in paralysis. In frontof this region is an area of the frontal lobe called the premotor cortex, wherecomplex movements are controlled.
Still farther forward is the prefrontal cortex,which exerts an inhibitory control over actions. Such distinctly human abilitiesas foreseeing the consequences of an action, exercising self-restraint, anddeveloping moral and ethical standards depend on the normal functioning of theprefrontal cortex. The parietal lobe, the part of the hemisphere that liesbehind the frontal lobe, contains the primary sensory cortex the part of thebrain. It receives sensory information from the opposite side of the body. Belowthe frontal and parietal lobes is the temporal lobe, which is involved withheari ng and memory. Behind the temporal lobe is the occipital lobe, the visualcenter of the brain. Here the signals that come to the brain from the eyes areput through very complex transformations in a process of analysis andintegration.
Cranial nerves are a group of 12 pairs of sensory, motor, or mixed(having separate sensory and motor fibers) nerves that connect with the brainstem and the lower parts of the brain.The Endocrine System.Endocrine glands secrete onto adjacent tissue where the hormone ispicked up by the blood, lymph system, or nerve cells and transported to thetarget organ. The adrenals, thyroid, parathyroid, pituitary, hypothalamus,pineal, and ovary are endocrine glands. The secretions of endocrine glands arecalled hormones. Mixed exocrine and endocrine glands, which secrete in both ways,include the liver, testes, and pancreas.
Endocrine glands release extremelysmall amounts because hormones are powerful substances. The activities of theendocrine glands form one of the most complex systems in the body. Although eachgland has its own unique function, the glands are interdependent, and thefunction of one depends on the activity of another. The hypothalamus producesseveral hormones, including those that regulate pituitary activity. Thepituitary produces its own hormones that regulate growth and stimulate otherendocrine glands. The adrenals, thyroid, testes, and ovaries are dependent uponpituitary stimulat ion.
The hormones these glands produce govern metabolism,blood pressure, water and mineral balance, and reproductive functions, and theyhelp defend against injury. The term hormone is derived from a Greek wordmeaning ‘stir up’.Drugs Affecting Behaviour.Many kinds of drugs are prescribed for anxiety, sleeping and nervousdisorders. Several types of sedative drugs induce sleep and cause intoxication.These drugs although prescribed for sleep disorders and anxiety problems, canalso cause physical and psychological dependence. These include ethyl alcohol,barbiturates, methaqualone, and many others.
There are of course everyday drugs that are consumed in enormousquantities by millions of people. Caffeine, nicotine and alcohol are used dailyby a large number of people, to the extent where they could be classed asaddictive. Alcohol addiction is by far one of the most common addictionsglobally. While there appears to be little evidence that using alcohol inmoderation does any damage, but excessive drinking is a major problem in manycountries causing many man hours of lost work, social and domestic violenceproblems.
Repeated heavy drinking can cause serious medical problems, liverdamage and irreversible brain damage in some cases.SENSORY PROCESSES.The term sensation refers to the process of receiving information in theform of energy (light, heat, sound etc.) from the world outside and sorting itout into the proper sense – vision, touch, hearing. Once that information hasbeen received, we interpret it and arrive at an understanding of what it means,a process referred to as perception. Sensation and perception make up anextensive information gathering system.Each sense has it’s own receptors that constantly monitor ourenvironment.
All sensory systems have certain characteristics: The sensorysystem must be selective, which means that only certain types of incominginformation are processed. For example, we have more than one kind of receiverfor touch. One which responds to changes in temperature and one which respondsto damaged cells. The sensory system must have an adjustable speed. Nerve fibresto the ear respond in less than a thousandth of a second because sudden noisedoes not require analysis, as it does a speedy response. However, the visualsystem will respond quickly to a blur as something comes towards us, apotential 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 toosensitive we would hear blood running through artery at the base of the ear.Sensory measurement must be reliable. Reliability comes from comparing incomingstimulus with the conditions around us.
Vision.The optic nerve delivers its impulses to a special area of the braincalled the visual center . This is where people “see” objects in the sense ofrecognizing and reacting to what their eyes look at. In other words, seeingalways involves the brain’s visual center. Here sensation turns into perception.The brain must learn by experience to analyze correctly the impulses itreceives from the eyes.
For instance, the lens system of the eye, like that of acamera, transmits its light pattern upside down. The brain has to learn that theimpulses received from the upper part of the retina represent the lower part ofthe object sighted and vice versa.In the brain also are located the centers that control all the eye’smuscular movements, such as the opening and closing of the iris, the focusing ofthe main lens, and the movement of the eyeball. The eyeball’s movement isvoluntary. Other eye adjustments are reflexes. Most individuals use both eyesto 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. Impulsesfrom both images are sent to the brain. Through experience these impulses areinterpreted as two views of the same object.
Because the eyes are about 2inches apart from pupil to pupil and therefore are looking at the object fromdifferent angles, the two views are not exactly alike. This is known as thestereoscopic effect. If the object is far away, the difference between theimages is slight.
If it is a few inches away, the difference is very great. Thebrain makes good use of this phenomenon. It learns to judge the distance of anobject b y the degree of difference between the images it receives from the twoeyes. 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 ofmillions of light receptors. The retina is connected to the brain by the opticnerve.
All of the structures needed to focus light onto the retina and tonourish it are housed in the eye, which is primarily a supporting shell for theretina. When light enters the eye it passes through the lens and focuses animage onto the retina. The retina has several layers, one of which containsspecial cells named for their shapes rods and cones.
Light-sensitive chemicalsin the rods and cones react to specific wavelengths of light and trigger nerveimpulses. These impulses are carried through the optic nerve to the visualcenter in the brain. Here they are interpreted, and sight occurs. Light mustpass through the covering layers of the retina to reach the layer of rods andcones. There are about 75 to 150 million rods and about 7 million cones in thehuman retina. Rods do not detect lines, points, or color. They perceive onlylight and darktones in an image.
The sensitive rods can distinguish outlines or silhouettesof objects in almost complete darkness. They make it possible for people to seein 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 atvarious speeds, or frequencies. The frequency of any given tone is measured interms of the number of cycles per second.
Sound travels slowly compared to lightat anything from 20-20,000 cycles per second. The sounds we hear have threebasic characteristics. Pitch, which is the frequency of the sound.
Timbre,determines the tonal quality . The loudness or intensity of the sound wave ismeasured in decibels. The human ear can pick up sounds just above ‘0’ decibels,otherwise there would be complete silence.Decibel Table.Decibels Noise Threshold40 Quiet office Normal60 Normal conservation Normal75 Road Traffic Noisy100 Subway Train Potential Damage130 Rock Concert Human Pain Threshold140 Aircraft Taking-off Human Pain ThresholdThe Structure of the Ear.
The ear has three separate sections the outer ear, the middle ear, andthe inner ear. Each section performs a specific function, related to eitherhearing or balance. The three parts of the outer ear are the auricle (alsocalled the pinna), the external auditory meatus (or ear canal), and the tympanicmembrane (or eardrum). The pinna collects sound waves from the air.
It funnelsthem into a tube, the external auditory meatus. This is a curved corridor thatleads to the tympanic membrane. The eardrum separates the external ear from themiddle ear. The middle ear is an irregular-shaped, air-filled space. A link ofthree tiny bones, the ossicles, spans the middle ear. When sound waves strikethe outer surface of the eardrum, it vibrates. These vibrations are mechanicallytransmitted through the middle ear by the ossicles, to the opening. This openingis the round window. Like the eardrum, the round window’s membrane transmitsvibrations. It directs vibrations into the inner ear, where they enter a f luidthat fills a structure called the cochlea. This is a coiled tube that resemblesa 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 ina basilar membrane, which extends throughout the cochlea. The unattached tips ofthese nerve endings are in contact with an overhanging membrane, called thetectorial membrane. When vibrations pass into the inner ear, they cause waves toform in the cochlear fluid. Receptor nerve cells in the organ of Corti arehighly sensitive to these waves. Other specialized nerve cells send theelectrochemical impulses produced by the wave motion into the cochlear branch ofthe acoustic nerve. This nerve carries the impulses to the brain, where sound isidentified.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 pathfor each of these tastes. However it appears that there is a pattern ofactivation in a number of different fibres providing the required sensory inputto the brain to distinguish these different tastes. The papillae on the surfaceof the tongue are the receptors for these taste sensations.Smell.Deciphering the sensory information for the sense of smell is notdissimilar to that of taste. In the olfactory area the nerve endings growthrough the mucous membrane which act as receptors to determine odors present inthe air we breathe.Touch.The skin or cutaneous sense has some 5 million sensors of at least 7types throughout the human body. The three major types are Meissner’s corpuscleswhich sense touch. The Pacinian corpuscle’s which determine movement andvibration and the Krause end bulbs which sense changes in temperature.Equilibrium and Proprioception.Proprioception (kinesthesia), establishes the position of limbs andunderlies the ability to assume and maintain posture, to move about in theenvironment, to manipulate objects and to be coordinated. These senses did notfigure prominently in the traditional account of senses because they have noexternal sources of adequate stimulation. They do have identifiable andunderstood sensory receptors. Both play an important role in maintaining postureand balance.PERCEPTION.Perception is the primary process by which we obtain knowledge about theworld. It involves the activity of our senses in responding to externalstimulation. Perception is a skill or set of skills, not simply the passivereception of external stimulation. The process of structuring these stimuli intoobjects we can perceive is called perceptual organisation. There are a numberof principles to perceptual organisation.Figure and Ground.Gestalt psychologists identified the tendency to differentiate betweenfigure and ground. The figure being the part of an image which we noticeprominently, opposed to the background, the ground. This theory not only appliesto visual items, but