Transcription
Chapter6LearningAfter reading this chapter, you would be able to describe the nature of learning,explain different forms or types of learning and the procedures used insuch types of learning,understand various psychological processes that occur during learningand influence its course,explain the determinants of learning, andfamiliarise yourself with some applications of learning principles.ContentsIntroductionNature of LearningParadigms of LearningClassical ConditioningDeterminants of Classical ConditioningOperant/Instrumental ConditioningDeterminants of Operant ConditioningClassical and Operant Conditioning : Differences (Box 6.1)Key Learning ProcessesLearned Helplessness (Box 6.2)Observational LearningCognitive LearningVerbal LearningConcept LearningSkill LearningTransfer of LearningFactors Facilitating LearningThe Learner : Learning StylesLearning DisabilitiesApplications of Learning PrinciplesLearning preserves errorsof the past as well as itswisdom.– A.N. WhiteheadKey TermsSummaryReview QuestionsProject Ideas
IntroductionAt the time of birth every human baby is equipped with the capacity to make alimited number of responses. These responses occur reflexively wheneverappropriate stimuli are present in the environment. As the child grows andmatures, s/he becomes capable of making diverse types of responses. Theseinclude identifying the images of some persons as one’s mother, father orgrandfather, using a spoon when eating food, and learning how to identifyalphabets, to write, and to combine them into words. S/he also observes othersdoing things in specific environmental conditions, and imitates them. Learningnames of objects such as book, orange, mango, cow, boy, and girl, and retainingthem is another important task. As one grows older, one observes many events orobjects, and learns their distinct features. Objects are categorised as ‘furniture’,‘fruits’, and so on. One also learns to drive a scooter or a car, to communicate withothers effectively, and to interact with others. It is all due to learning that a personbecomes hard working or indolent, socially knowledgeable, skilled, andprofessionally competent. Each individual manages her or his life and solves allkinds of problems because of the capacity to learn and adapt. This chapter focuseson the various aspects of learning. First, learning is defined and characterised asa psychological process. Second, an account is presented that explains how onelearns. A number of learning methods that account for simple to complex types oflearning are described. In the third section, some empirical phenomena, that occurin the course of learning, are explained. In the fourth section, different factors thatdetermine the speed and extent of learning are described including differentlearning styles and learning disabilities.NATUREOFL EARNINGAs indicated above learning is a key processin human behaviour. It refers to a spectrumof changes that take place as a result of one’sexperience. Learning may be defined as “anyrelatively permanent change in behaviour orbehavioural potential produced by experience”.One must remember that some behaviouralchanges occur due to the use of drugs, orfatigue. Such changes are temporary. They arenot considered learning. Changes due topractice and experience, which are relativelypermanent, are illustrative of learning.Features of LearningThe process of learning has certain distinctivecharacteristics. The first feature is that learning108Psychologyalways involves some kinds of experience. Weexperience an event occurring in a certainsequence on a number of occasions. If an eventhappens then it may be followed by certainother events. For example, one learns that ifthe bell rings in the hostel after sunset, thendinner is ready to be served. Repeatedexperience of satisfaction after doingsomething in a specified manner leads to theformation of habit. Sometimes a singleexperience can lead to learning. A child strikesa matchstick on the side of a matchbox, andgets her/his fingers burnt. Such an experiencemakes the child learn to be careful in handlingthe matchbox in future.Behavioural changes that occur due tolearning are relatively permanent. They mustbe distinguished from the behavioural changesthat are neither permanent nor learned. For
example, changes in behaviour often occurdue to the effects of fatigue, habituation, anddrugs. Suppose you are reading your textbookof psychology for sometime or you are tryingto learn how to drive a motor car, a time comeswhen you will feel tired. You stop reading ordriving. This is a behavioural change due tofatigue, and is temporary. It is not consideredlearning.Let us take another case of change in one’sbehaviour. Suppose in the vicinity of yourresidence a marriage is being performed. Itgenerates a lot of noise, which continues tilllate night. In the beginning, the noise distractsyou from whatever you are doing. You feeldisturbed. While the noise continues, youmake some orienting reflexes. These reflexesbecome weaker and weaker, and eventuallybecome undetectable. This is also one kind ofbehavioural change. This change is due tocontinuous exposure to stimuli. It is calledhabituation. It is not due to learning. You musthave noticed that people who are on sedativesor drugs or alcohol, their behaviour changesas it affects physiological functions. Suchchanges are temporary in nature anddisappear, as the effect wears out.Learning involves a sequence ofpsychological events. This will become clear ifwe were to describe a typical learningexperiment. Suppose psychologists areinterested in understanding how a list of wordsis learned. They will go through the followingsequence : (i) do a pre-test to know how muchthe person knows before learning, (ii) presentthe list of words to be remembered for a fixedtime, (iii) during this time the list of words isprocessed towards acquiring new knowledge,(iv) after processing is complete, newknowledge is acquired (this is LEARNING), and(v) after some time elapses, the processedinformation is recalled by the person. Bycomparing the number of words which aperson now knows as compared to what s/heknew in the pre-test, one infers that learningdid take place.Thus, learning is an inferred process andis different from performance. Performanceis a person’s observed behaviour or responseor action. Let us understand what is meantby the term inference. Suppose you are askedby your teacher to memorise a poem. You readthat poem a number of times. Then you saythat you have learned the poem. You are askedto recite the poem and you are able to reciteit. The recitation of the poem by you is yourperf o rmance. On the basis of yourperformance, the teacher infers that you havelearned the poem.P ARADIGMSOFLEARNINGLearning takes place in many ways. There aresome methods that are used in acquisition ofsimple responses while other methods areused in the acquisition of complex responses.In this section you will learn about all thesemethods. The simplest kind of learning iscalled conditioning. Two types of conditioninghave been identified. The first one is calledclassical conditioning, and the secondinstrumental/operant conditioning. Inaddition, we have observational learning,cognitive learning, verbal learning, conceptlearning, and skill learning.C LASSICAL CONDITIONINGThis type of learning was first investigated byIvan P. Pavlov. He was primarily interested inthe physiology of digestion. During his studieshe noticed that dogs, on whom he was doinghis experiments, started secreting saliva assoon as they saw the empty plate in whichfood was served. As you must be aware, salivasecretion is a reflexive response to food orsomething in the mouth. Pavlov designed anexperiment to understand this process in detailin which dogs were used once again. In thefirst phase, a dog was placed in a box andharnessed. The dog was left in the box for sometime. This was repeated a number of times ondifferent days. In the meantime, a simplesurgery was conducted, and one end of a tubewas inserted in the dog’s jaw and the other endof the tube was put in a measuring glass. Theexperimental setup is illustrated in Figure 6.1.Chapter 6 Learning109
In the second phase of the experiment, thedog was kept hungry and placed in harnesswith one end of the tube ending in the jawand the other end in the glass jar. A bell wasOne-wayglass wallFoodTube fr omsalivary glandsCup forRecor dingmeasuring salivadeviceFig.6.1 : A Dog in Pavlovian Harness for Conditioningsounded and immediately thereafter food (meatpowder) was served to the dog. The dog wasallowed to eat it. For the next few days,everytime the meat powder was presented, itwas preceded by the sound of a bell. After anumber of such trials, a test trial wasintroduced in which everything was the sameas the previous trials except that no foodfollowed the sounding of the bell. The dog stillsalivated to the sound of the bell, expectingpresentation of the meat powder as the soundof bell had come to be connected with it. Thisassociation between the bell and food resultedin acquisition of a new response by the dog,i.e. salivation to the sound of the bell. This hasbeen termed as conditioning. You may havenoticed that all dogs salivate when they arepresented with food. Food is thus anTable 6.1110Unconditioned Stimulus (US) and salivationwhich follows it, an Unconditioned Response(UR). After conditioning, salivation started tooccur in the presence of the sound of the bell.The bell becomes a Conditioned Stimulus(CS) and saliva secretion a ConditionedResponse (CR). This kind of conditioning iscalled classical conditioning. The procedureis illustrated in Table 6.1. It is obvious thatthe learning situation in classical conditioningis one of S–S learning in which one stimulus(e.g., sound of bell) becomes a signal foranother stimulus (e.g., food). Here one stimulussignifies the possible occurrence of anotherstimulus.Examples of classical conditioning aboundin everyday life. Imagine you have just finishedyour lunch and you are feeling satisfied. Thenyou see some sweet dish served on theadjoining table. This signals its taste in yourmouth, and triggers the secretion of saliva. Youfeel like eating it. This is a conditioned response(CR). Let us take another example. In the earlystages of childhood, one is naturally afraid ofany loud noise. Suppose a small child catchesan inflated balloon which bursts in her/hishands making a loud noise. The child becomesafraid. Now the next time s/he is made to holda balloon, it becomes a signal or cue for noiseand elicits fear response. This happens becauseof contiguous presentation of balloon as aconditioned stimulus (CS) and loud noise asan unconditioned stimulus (US).Determinants of Classical ConditioningHow quickly and strongly acquisition of aresponse occurs in classical conditioningdepends on several factors. Some of the majorRelationship of Stages of Conditioning and OperationsStages ofConditioningNature of StimulusNature of ResponseBeforeFood (US)Sound of the BellSalivation (UR)Alertness (No Specific Response)DuringSound of the Bell (CS) Food (US)Salivation (UR)AfterSound of the Bell (CS)Salivation (CR)Psychology
factors influencing learning a CR are describedbelow:1. T ime Relations between Stimuli : Theclassical conditioning procedures, discussedbelow, are basically of four types based on thetime relations between the onset of conditionedstimulus (CS) and unconditioned stimulus(US). The first three are called forwardconditioning procedures, and the fourth oneis called backward conditioning procedure.The basic experimental arrangements of theseprocedures are as follows:a) When the CS and US are presentedtogether, it is called simultaneousconditioning.b) In delayed conditioning, the onset ofCS precedes the onset of US. The CSends before the end of the US.c) In trace conditioning, the onset andend of the CS precedes the onset of USwith some time gap between the two.d) In backward conditioning, the USprecedes the onset of CS.It is now well established that delayedconditioning procedure is the most effectiveway of acquiring a CR. Simultaneous and traceconditioning procedures do lead to acquisitionof a CR, but they require greater number ofacquisition trials in comparison to the delayedconditioning procedure. It may be noted thatthe acquisition of response under backwardconditioning procedure is very rare.2. Type of Unconditioned Stimuli : Theunconditioned stimuli used in studies ofclassical conditioning are basically of twotypes, i.e. appetitive and aversive. Appetitiveunconditioned stimuli automatically elicitsapproach responses, such as eating, drinking,caressing, etc. These responses givesatisfaction and pleasure. On the other hand,aversive US, such as noise, bitter taste, electricshock, painful injections, etc. are painful,harmful, and elicit avoidance and escaperesponses. It has been found that appetitiveclassical conditioning is slower and requiresgreater number of acquisition trials, butaversive classical conditioning is establishedin one, two or three trials depending on theintensity of the aversive US.3. Intensity of Conditioned Stimuli : Thisinfluences the course of both appetitive andaversive classical conditioning. More intenseconditioned stimuli are more effective inaccelerating the acquisition of conditionedresponses. It means that the more intense theconditioned stimulus, the fewer are thenumber of acquisition trials needed forconditioning.Activity 6.1In order to understand and explain conditioning,you may carry out the following exercise. Takea few pieces of mango pickle on a plate andshow it to the students in the classroom. Askthem what they experienced in their mouth?Most of your classmates are likely to reportsome salivation in their mouth.OPERANT/INSTRUMENTAL CONDITIONINGThis type of conditioning was first investigatedby B.F. Skinner. Skinner studied occurrenceof voluntary responses when an organismoperates on the environment. He called themoperants. Operants are those behaviours orresponses, which are emitted by animals andhuman beings voluntarily and are under theircontrol. The term operant is used because theorganism operates on the environment.Conditioning of operant behaviour is calledoperant conditioning.Skinner conducted his studies on rats andpigeons in specially made boxes, called theSkinner Box. A hungry rat (one at a time) isplaced in the chamber, which was so built thatthe rat could move inside but could not comeout. In the chamber there was a lever, whichwas connected to a food container kept on thetop of the chamber (see Figure 6.2). When thelever is pressed, a food pellet drops on theplate placed close to the lever. While movingaround and pawing the walls (exploratorybehaviour), the hungry rat accidentally pressesthe lever and a food pellet drops on the plate.The hungry rat eats it. In the next trial, aftera while the exploratory behaviour again starts.As the number of trials increases, the rat takesChapter 6 Learning111
lesser and lesser time to press the lever for food.Conditioning is complete when the rat pressesthe lever immediately after it is placed in thechamber. It is obvious that lever pressing isan operant response and getting food is itsconsequence.response. They include its types – positive ornegative, number or frequency, quality –superior or inferior, and schedule – continuousor intermittent (partial). All these featuresinfluence the course of operant conditioning.Another factor that influences this type oflearning is the nature of the response orbehaviour that is to be conditioned. Theinterval or length of time that lapses betweenoccurrence of response and reinforcement alsoinfluences operant learning. Let us examinesome of these factors in detail.Types of ReinforcementFig.6.2 : Skinner BoxIn the above situation the response isinstrumental in getting the food. That is why,this type of learning is also calledinstrumental conditioning. Examples ofinstrumental conditioning abound in oureveryday life. Children who want to have somesweets in the absence of their mother learn tolocate the jar in which mother hides the sweetsfor safekeeping and eat it. Children learn tobe polite and say ‘please’ to get favours fromtheir parents and others. One learns to operatemechanical gadgets such as radio, camera,T. V., etc. based on the principle ofinstrumental conditioning. As a matter of facthuman beings learn short cuts to attaindesired goals or ends through instrumentalconditioning.Determinants of Operant ConditioningYou have noted that operant or instrumentalconditioning is a form of learning in whichbehaviour is learned, maintained or changedthrough its consequences. Such consequencesare called reinforcers. A reinforcer is definedas any stimulus or event, which increases theprobability of the occurrence of a (desired)response. A reinforcer has numerous features,which affect the course and strength of a112PsychologyReinforcement may be positive or negative.Positive reinforcement involves stimuli thathave pleasant consequences. They strengthenand maintain the responses that have causedthem to occur. Positive reinforcers satisfyneeds, which include food, water, medals,praise, money, status, information, etc.Negative reinforcers involve unpleasant andpainful stimuli. Responses that lead organismsto get rid of painful stimuli or avoid and escapefrom them provide negative reinforcement.Thus, negative reinforcement leads to learningof avoidance and escape responses. Forinstance, one learns to put on woollen clothes,burn firewood or use electric heaters to avoidthe unpleasant cold weather. One learns tomove away from dangerous stimuli becausethey provide negative reinforcement. It maybe noted that negative reinforcement is notpunishment. Use of punishment reduces orsuppresses the response while a negativereinforcer increases the probability ofavoidance or escape response. For instance,drivers and co-drivers wear their seat belts toavoid getting injured in case of an accident orto avoid being fined by the traffic police.It should be understood that nopunishment suppresses a responsepermanently. Mild and delayed punishmenthas no effect. The stronger the punishment,the more lasting is the suppression effect butit is not permanent.Sometimes punishment has no effectirrespective of its intensity. On the contrary,the punished person may develop dislike and
hatred for the punishing agent or the personwho administers the punishment.Number of Reinforcement and other FeaturesIt refers to the number of trials on which anorganism has been reinforced or rewarded.Amount of reinforcement means how muchof reinforcing stimulus (food or water orintensity of pain causing agent) one receiveson each trial. Quality of reinforcement refersto the kind of reinforcer. Chickpeas or piecesof bread are of inferior quality as comparedwith raisins or pieces of cake as reinforcer.The course of operant conditioning is usuallyaccelerated to an extent as the number,amount, and quality of reinforcementincreases.Schedules of ReinforcementA reinforcement schedule is the arrangementof the delivery of reinforcement duringconditioning trials. Each schedule ofreinforcement influences the course ofconditioning in its own way; and thusconditioned responses occur with differentialcharacteristics. The organism being subjectedto operant conditioning may be givenreinforcement in every acquisition trial or inBox1.2.6.1some trials it is given and in others it isomitted. Thus, the reinforcement may becontinuous or intermittent. When a desiredresponse is reinforced every time it occurs wecall it continuous reinforcement. In contrast,in intermittent schedules responses aresometimes reinforced, sometimes not. It isknown as partial reinforcement and has beenfound to produce greater r esistance toextinction – than is found with continuousreinforcement.Delayed ReinforcementThe effectiveness of reinforcement isdramatically altered by delay in the occurrenceof reinforcement. It is found that delay in thedelivery of reinforcement leads to poorer levelof performance. It can be easily shown byasking children which reward they will preferfor doing some chore. Smaller rewardsimmediately after doing the chore will bepreferred rather than a big one after a longgap.Key Learning ProcessesWhen learning takes place, be it classical oroperant conditioning, it involves theoccurrence of certain processes. These includeClassical and Operant Conditioning : DiffDifferenceserencesIn classical conditioning, the responses areunder the control of some stimulus becausethey are reflexes, automatically elicited bythe appropriate stimuli. Such stimuli areselected as US and responses elicited bythem as UR. Thus Pavlovian conditioning, inwhich US elicits responses, is often calledrespondent conditioning.In instrumental conditioning, responsesare under the control of the or ganism andare voluntary responses or ‘operants’. Thus,in the two for ms of conditioning differenttypes of responses are conditioned.In classical conditioning the CS and US arewell-defined, but in operant conditioning CSis not defined. It can be inferred but is notdirectly known.3.4.In classical conditioning, the experimentercontrols the occurrence of US, while in operantconditioning the occurrence of the reinforcer isunder the control of the organism that is learning.Thus, for US in classical conditioning theorganism remains passive, while in operantconditioning the subject has to be active in orderto be reinforced.In the two forms of conditioning, the technicalter ms used to characterise the experimentalproceedings are dif ferent. Moreover what is calledreinforcer in operant conditioning is called US inclassical conditioning. An US has two functions.In the beginning it elicits the response and alsoreinforces the response to be associated andelicited later on by the CS.Chapter 6 Learning113
Box6.2Learned HelplessnessIt is an interesting phenomenon, which is a resultof an interaction between the two forms ofconditioning. Learned helplessness underliespsychological cases of depression. Seligman andMaier demonstrated this phenomenon in a studyon dogs. First, they subjected dogs to sound (CS)and electric shock (US) using classical conditioningprocedure. The animal had no scope to escape oravoid the shock. This pairing was repeated anumber of times. Then the dogs were subjected toshock in an operant conditioning procedure. Thedogs could escape the shock by pressing theirheads against the wall. After having experiencedinescapable shock in the Pavlovian contingency,the dog failed to escape or avoid shock in theoperant conditioning procedur e. The dog justsuffered the shock through, and did not attempt toescape. This behaviour of the dog was called lear nedhelplessness.This phenomenon has been shown to be operativein humans also. It has been found that continuousfailure in a set of tasks shows the occurrence oflearned helplessness. In an experimental study, thesubjects ar e initially given failure experienceirrespective of their performance. In the second phasethe subjects are given a task. Learned helplessnessis often measured in terms of the subject’s ability andpersistence before they give up the task. Continuousfailure leads to little persistence and poor performance.This shows helplessness. There are numerous studiesthat demonstrate that persistent depression is oftencaused by lear ned helplessness.reinforcement, extinction or non-occurrenceof learned response, generalisation oflearning to other stimuli under somespecifiable conditions, discriminationbetween reinforcing and non-reinforcingstimuli, and spontaneous recovery.lead to the desired response. Such a responseis shaped by reinforcing successiveapproximations to the desired response.ReinforcementReinforcement is the operation ofadministering a reinforcer by the experimenter.Reinforcers are stimuli that increase the rateor probability of the responses that precede.We have noted that reinforced responsesincrease in rate, while non-reinforcedresponses decrease in rate. A positivereinforcer increases the rate of response thatprecedes its presentation. Negative reinforcersincrease the rate of the response that precedestheir removal or termination. The reinforcersmay be primary or secondary. A primaryreinforcer is biologically important since itdetermines the organism’s survival (e.g., foodfor a hungry organism). A secondary reinforceris one which has acquired characteristics ofthe reinforcer because of the organism’sexperience with the environment. Wefrequently use money, praise, and grades asreinforcers. They are called secondaryreinforcers. Systematic use of reinforcers can114PsychologyExtinctionExtinction means disappearance of a learnedresponse due to removal of reinforcement fromthe situation in which the response used tooccur. If the occurrence of CS-CR is notfollowed by the US in classical conditioning,or lever pressing is no more followed by foodpellets in the Skinner box, the learnedbehaviour will gradually be weakened andultimately disappear.Learning shows resistance to extinction.It means that even though the learnedresponse is now not reinforced, it wouldcontinue to occur for sometime. However, withincreasing number of trials withoutr einforcement, the response strengthgradually diminishes and ultimately it stopsoccurring. How long a learned response showsresistance to extinction depends on a numberof factors. It has been found that withincreasing number of reinforced trialsresistance to extinction increases and learnedresponse reaches its highest level. At this levelperformance gets stabilised. After that thenumber of trials do not make a difference in
Generalisation and DiscriminationThe processes of generalisation anddiscrimination occur in all kinds of learning.However, they have been extensivelyinvestigated in the context of conditioning.Suppose an organism is conditioned to elicit aCR (saliva secretion or any other reflexiveresponse) on presentation of a CS (light orsound of bell). After conditioning is established,and another stimulus similar to the CS (e.g.,ringing of telephone) is presented, the organismmakes the conditioned response to it. Thisphenomenon of responding similarly to similarstimuli is known as generalisation. Again,suppose a child has learned the location of ajar of a certain size and shape in which sweetsare kept. Even when the child’s mother is notaround, the child finds the jar and obtains thesweets. This is a learned operant. Now thesweets are kept in another jar of a differentsize and shape and at a different location inthe kitchen. In the absence of the mother thechild locates the jar and obtains the sweets.This is also an example of generalisation. Whena learned response occurs or is elicited by anew stimulus, it is called generalisation.Another process, which is complimentaryto generalisation, is called discrimination.Generalisation is due to similarity whilediscrimination is a response due to difference.For example, suppose a child is conditionedto be afraid of a person with a long moustacheand wearing black clothes. In subsequentsituation, when s/he meets another persondressed in black clothes with a beard, the childshows signs of fear. The child’s fear isgeneralised. S/he meets another stranger whois wearing grey clothes and is clean-shaven.The child shows no fear. This is an example ofdiscrimination. Occurrence of inative response depends on thediscrimination capacity or discriminationlearning of the organism.Spontaneous RecoverySpontaneous recovery occurs after a learnedresponse is extinguished. Suppose anorganism has learned to make a response forgetting reinforcement, then the response isextinguished and some time lapses. A questionnow may be asked, whether the response iscompletely extinguished, and will not occur ifthe CS is presented. It has been demonstratedthat after lapse of considerable time, thelearned or CR recovers and occurs to the CS.The amount of spontaneous recovery dependson the duration of the time lapsed after theextinction session. The longer the duration oftime lapsed, the greater is the recovery oflearned response. Such a recovery occursspontaneously. Fig.6.3 shows thephenomenon of spontaneous recovery.(1)Acquisition(CS US)Strength of the CRthe response strength. Resistance to extinctionincreases with increasing number ofreinforcements during acquisition trials,beyond that any increase in number ofreinforcement reduces the resistance toextinction. Studies have also indicated thatas the amount of reinforcement (number offood pellets) increases during the acquisitiontrials, resistance to extinction decreases.If the reinforcement is delayed duringacquisition trials, the resistance to extinctionincreases. Reinforcement in every acquisitiontrial makes the learned response to be lessr esistant to extinction. In contrast,intermittent or partial reinforcement duringacquisition trials makes a learned responsemore resistant to extinction.(2)Extinction(CS alone)(3)Spontaneousrecovery(CS alone)RestBaselineTrialsFig.6.3 : Phenomenon of Spontaneous RecoveryChapter 6 Learning115
OBSER VATIONAL LEARNINGThe next form of learning takes place byobserving others. Earlier this form of learningwas called imitation. Bandura and hiscolleagues in a series of experimental studiesinvestigated observational learning in detail.In this kind of learning, human beings learnsocial behaviours, therefore, it is sometimescalled social learning. In many situationsindividuals do not know how to behave. Theyobserve others and emulate their behaviour.This form of learning is called modeling.Examples of observational learningabound in our social life. Fashion designersemploy tall, pretty, and gracious young girlsand tall, smart, and well-built young boys forpopularising clothes of different designs andfabrics. People observe them on televisedfashion shows and advertisements inmagazines
A child strikes a matchstick on the side of a matchbox, and gets her/his fingers bur nt. Such an experience . names of objects such as book, orange, mango, cow, boy, and girl, and retaining them is another important task. As one grows older, one observes many events or .
