Chapter 4 Learning and Memory

8/10/2019 Chapter 4 Learning and Memory

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4.1 INTRODUCTION

4.1.1 Why Are Learning and Memory So Important?

Is this a joke? I have to learn about learning? As a student, you spend a lot of your time tryingto learn the material from your classes, but did you ever think about how much you are learningall the time from your life? Without realizing it, we are constantly learning by making associa-

tions, from the reactions we get from others, and by imitating people who are important to us.Many of us are also teaching others and we want to know how to maximize others learning.

And what happens once you have learned the material from your classes? Is it of any use to youif you cant remember what you learned? What is the part of the eye that focuses light? How do

you study for an exam? How did you do on your last exam? Your ability to answer all of thesequestions relies on your memory. Your memory is a vast storehouse of knowledge, information,and experiences and is vital to every part of your daily life. As a student, it is obviously importantto remember things you learn in class. When you think of your memory, you probably also bringto mind important events from your past like your high school graduation or maybe your firstkiss. But our memories are so much more than just facts and stories from our lives.

Chapter 4Learning and Memory

How Do I Learn and Remember, and Why Do I Forget?

Debora Herold, Ph.D. and

Shenan Kroupa, Ph.D.


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T r u s t e e s o f I n d i a n a U n i v e r s i t y

The first underlying theme of this course is that the science of psychology seeks to describe, explain,predict, and change behavior. Studying the psychology of learning and memory will help you un-derstand what learning and memory are and how they occur. It should help you come up with waysto study and retain material better, give you tools to changeyour own life for the better (New Yearsresolutions, anyone?), and give you a game plan for teaching children and pets to behave. Every timethe topic of memory comes up in Introductory Psychology, students are always surprised by and ex-cited about how applicable the material is to their daily lives. By the time we finish the chapter, many

immediately begin applying the new strategies they learned to improve their retention of material.

To get you started on the right track, read carefully and mindfully. As you read, think about how theinformation relates to your own life, memories you have, and your own nave theories about how welearn and how our memory functions. Pause every so often and ask yourself about what you read inthe preceding paragraphs to make sure you have been paying attention. If you find your mind start-ing to wander, take a short break, switch to another subject, and then come back to the material once

your mind is refreshed. You will notice that each section in this and all other chapters begins with aquestion. When you come to one of these questions, try to answer it for yourself before reading on.

4.2 LEARNING

4.2.1 What Is Learning and How Does It Happen?

When experiences lead you to know new information, possess new skills, or demonstrate new be-haviors we say that learninghas taken place. Learning is a relatively permanent change in behavioror knowledge that is due to experience. So when you know the capitals of all 50 states, when youlearn how to whistle, or when you successfully find the last parking spot on campus, you can beproud of all your learning. Because learning comes from experience, we can also say that its purposeis to help you be more successful, or adapt well, when those same experiences come up again. Life

would be very difficult without learning because you would always be starting over from square one.

4.2.2 How Do We Learn About Signals and Why Do They Matter?

We engage in different types of learning everyday. When experiences cause us to link things in theenvironment together, we refer to this as associative learning. One of the most basic ways that welearn is by forming associations (links) between stimuli (things) that happen at about the same time.In classical conditioning, we learn to associate a neutral (meaningless) stimulus in our environment

with a different, meaningfulstimulus that is very important to us because of its ability to elicit aresponse. Simply by occurring at the same time as the meaningful stimulus, the neutral stimuluseventually becomes powerful enough to elicit a response by itself. Wow! Thats some kind of

power.

Pavlov and Classical Conditioning

This type of learning was discovered by accident as Ivan Pavlov studied how different types of foodmake dogs drool. To do this, he would buckle the dogs into harnesses and then give them differ-ent types of food that would naturally make the dogs drool. Surprisingly, as the days of the studycontinued, the dogs started to drool as soon as they were put in the harnesses, well before they hadany food. The harness acted as a signalto the dogs that food would soon arrive: it allowed them topredict what was about to occur. In other words, the harness provided the dogs with informationthat they could then use to figure out what would happen next.


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Pavlov was annoyed, but decided to make lemonade out of lemons and see if he could teach, orcondition, the dogs to drool to other things that should not be naturally drool-worthy. For example,the sound of a buzzer, the ringing of a tuning fork, or a flash of bright light does not usually makeFido slobber.

How did Pavlov do this? Well, just like the dogs formed an association between being harnessedright before the food, Pavlov made a buzzer sound occur just before the dog received food (Figure

4.1). This close timing was important. For an association to form, little time can pass in between.When things are closely linked together in time, we say they have temporal contiguity.

Figure 4.1 The process of classical conditioning

The diagram shows Pavlovs classical conditioning procedure. As you can see, classical conditioning involves the

learning of an association between a neutral stimulus (the buzzer) and a meaningful stimulus (food).


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This contiguous pairing of the signal and food happened over and over: it typically takes a largenumber of repetitions, or trials, to make an association happen! Eventually, the dog just needed tohear the buzzer to begin drooling away. The dogs were conditioned to drool to those things thatpreviously meant nothing to them. Pavlov taught them that these sounds or the appearance of lightare now drool-worthy! Why, you might ask? Because they served as signals that reliably predictedthe arrival of foodsomething every dog will automatically drool over! We can also say that thedogs acquired this learning of the association between the signals and the food: it is called acquisition

when learning occurs.

Now before you start thinking that classical conditioning only applies to salivating dogs, lets look ata human example: security blankets. My guess is that many of you might not like to admit it today,but as a young child you were obsessed with a blanket left over from when you were a baby! Kids

who have security blankets will drag them everywhere if they are allowed, so after many years ofuse, these once cute baby blankets turn into threadbare, dirty, often smelly and torn cloth. But thekids still love them! How can it be that a piece of fabric, even one that has become no more than arag, can give kids such a secure and safe feeling? Classical Conditioning!

Here are the details. When a mom breastfeeds her baby, the baby feels happy, warm, safe, and loved

at each feeding. When a baby is born, parents often get gifts, and maybe one of those gifts is a nicebaby blanket. Maybe the mom starts to get into the habit of covering the baby with this baby blanketas she nurses and this continues for a while. The baby starts to acquire an association between theblanket and nursing, so that pretty soon those nice happy, warm, safe, loving feelings come from

just touching the blanket. Without meaning to, the mother classically conditioned her baby to feelsecure from a simple piece of cloth that previously had no meaning for the child. This again is anexample of acquisition because learning has occurred.

One of the easiest ways to understand classical conditioning is to notice how in each example weare able to get the same response (drooling; feeling secure) from a new cause, that is, from a newstimulus. We start out with a meaningful stimulus that automatically causes the response: foodcauses dogs to drool; nursing makes babies feel secure. Then, we cause a second stimulus to tagalong with the first one: we add a buzzer to the food; we add a blanket to the nursing. In the end,

we have transferred the response from the first stimulus to the second: the dog now drools to thebuzzer; the baby feels secure with the blanket.

Pavlov added some additional vocabulary to define the different parts of the story of acquisition.He talks about some things being unconditioned, which means unlearned. In the dog study, whatdoes not require teaching is the dog responding with drool to the stimulus of food; in the babystory, what does not require learning is the baby responding with feeling secure to the stimulus ofbreastfeeding. So Pavlov would call foodand breastfeedingexamples of an unconditioned stimulus(US). In other words, an unconditioned stimulus is an event or signal that reliably elicits a response

without prior learning. Drooling andfeeling securewould be examples of an unconditioned response

(UR), an automatic or unlearned reaction that automatically follows the unconditioned stimulus.The US always automatically causes the URit is a reflex.

Other parts of the story require or reflect learning, or conditioning. In the dog study, the buzzerrequires learning to give that stimulus meaning (dogs do not naturally care about buzzers), andthe fact that the dog learns to respond by drooling then reflects that conditioning occurred; like-

wise in the baby story, the blanket requires learning to give that stimulus meaning (babies donot naturally care about blankets), and the fact that the baby learns to respond by feeling secure


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reflects that conditioning occurred. So Pavlov would call the buzzerand the blanketexamples of aconditioned stimulus (CS)because they are learned signals. In other words, a conditioned stimu-lus is a previously neutral or meaningless signal, that begins to produce a response after beingpaired with the unconditioned stimulus. Droolingand feeling securewould now be examples of aconditioned response (CR)or learned reaction. Acquisition occurs when the CS causes the CR;learning has occurred.

One of the best tricks to decoding the alphabet soup of a classical conditioning study is to rememberthat we are transferring a response, that began as a reflex, from one stimulus to a new stimulus. Theunconditioned response will usually be the same as the conditioned response (UR = CR). The dogused to just drool to food; Pavlov conditioned the dog to drool to a buzzer. The baby used to justfeel secure while nursing; the mom conditioned the baby to feel secure to a blanket.

For this transfer to work, remember that we need temporal contiguity. Another way to say it is thatthe conditioned stimulus (CS) needs to occur very close to when the unconditioned stimulus (US)occurs, so that it is indeed predicting the occurrence of the US. So after Pavlov sounded the buzzer,he could not wait forever to give the dogs food and have a hope that they would form an association.

We also know that the best timing of these two stimuli is delay conditioning: the conditioned stimu-lus (CS) should start just before (~0.5 sec) and overlap a bit with the unconditioned stimulus (US)(Figure 4.2). The baby forms a strong association when she is wrapped in a blanket just before andremains in the blanket while breastfeeding. Finally, most situations require many repetitions of thesestimuli happening at about the same time; it takes time for an association to occur.

Figure 4.2 Delay conditioning

Another interesting thing about classical conditioning is that the learning can extend to signals thatare similar to one that has been given meaning. For example, imagine if Pavlov took his laboratory

dogs home with him for Spring Break, only to find that every time the washing machine buzzed,puddles of drool would appear on his carpet. The dogs had not been trained to that particularbuzzer, but the sound was similar enough so they responded in the way that they had been taught.

This extension is calledstimulus generalization; things that are similar to the conditioned stimulus(CS) also produce the conditioned response (CR). In this case, the dogs have generalized that allbuzzers are drool-worthy.


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Fear and Classical Conditioning

In the 1920s, a controversial experiment by John Watson showed that people also experience stimu-lus generalization. Watson classically conditioned a nine-month-old baby they called Little Albertto fear a white rat (Figure 4.3). He did this by showing Little Albert a tame white rat and at aboutthe same time, hitting a steel bar with a hammer to make a loud noise (the unconditioned stimulus).In the beginning, it was just the loud sound that would make Little Albert cry in fright; he had no

fear of the white rat at first. But, because the rat and noise combination happened over and over,eventually Little Albert just had to see the rat (the conditioned stimulus) to cry out in fear. So theresponse of fear was successfully transferred from one thing, the noise (or US) to a new thing, therat (or CS).

Figure 4.3 A classically conditioned fear response

Little Alberts story becomes one of stimulus generalization after that. It turned out that Albertwas not only afraid of white rats, but now he was also afraid of white rabbits, a white fur coat, andmost troublingSanta Claus white beard! Even though Albert had never been trained to fear thesethings, they were similar enough to the stimulus he had learned to fear that his fear generalized toall of those items.


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Extinction and Spontaneous Recovery

At this point, you might be wondering if Pavlovs dogs had a lifetime of slobber, if children withsecurity blankets will grow up to be adults who cannot start a new job without that blanket in hand,or if poor Little Albert had a lifetime phobia of white fur. The answer is likely, no. It turns out thatassociations do not last forever. Remember that these associations were based on the animal or per-son making predictions of what to expect at about the same time. If that expectation is not met for

a long time, then the association is broken. So if Pavlovs dogs never got food after hearing a buzzer,eventually the buzzer would not mean anything to them and they would stop drooling. As a childgets older, she will be less and less likely to experience her mother and her security blanket at thesame time, so it is likely that the blanket will lose its magical powers of security. Finally, we do notknow what happened to Little Albert, but I would guess that in the rest of his life, he never heard ascary noise when he saw a white rat, so he would have eventually lost that fear and all the generalizedfears related to white fuzzy stuff. This breaking of an association is calledstimulus extinction. Thisoccurs when the same signal no longer produces the same response. Just like the extinct dinosaurs

who do not interfere with our life today, that old conditioned stimulus no longer has meaning tous. To put this in terms of the alphabet soup, we can say that extinction is when the unconditionedstimulus (US) no longer occurs at the same time as the conditioned stimulus (CS), so the association

fades away and the conditioned response (CR) goes away.

However, extinction of a stimulus is not as permanent as extinction of a species. Sometimes, we see ex-amples ofspontaneous recovery, when a conditioned response reemerges after extinction has occurred,after a brief rest period that is free from testing (Figure 4.4). For example, when Pavlovs dogs didnt getfood after the sound, they stopped drooling to the buzzer. Next, he let them have a day off from hearingthe buzzer. The following day, Pavlov hit the buzzer again, and the dogs were back to their old habitof drooling. So, spontaneous recovery shows us that learning does not go away completely. To use thealphabet soup, we could say that spontaneous recovery happens after extinction when some time passesby without experiencing the conditioned stimulus (CS). The evidence for this is that the conditionedresponse (CR) returns once again. Lets hope for Little Alberts sake that this did not happen to him,although it does make you wonder if occasionally the sight of Santa Claus at the mall caused him a bitof a fright! On the other hand, not forgetting what we have learned may serve a protective purpose.

Figure 4.4 Extinction and spontaneous recovery in Pavlovs laboratory


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This demonstration involved a dog that had already been conditioned to salivate (the CR) to just the sound of the

buzzer (the CS). During the extinction phase, the CS was repeatedly presented at three-minute intervals without

the UCS. As you can see, over the course of the trials, the amount of saliva secreted by the dog quickly decreased

to zero. This indicates that extinctionhad occurred. After an overnight rest period, the CS was presented again. The

dog secreted saliva once more, evidence for the spontaneous recovery of the conditioned response.

Source: Data adapted from Pavlov (1927).

Why cant I remember the answer to this exam question? We are all familiar with that sinking feel-ing: were taking a test, and get to a question that we knowwe know. Why wont the answer cometo mind? The answer to thatquestion is that what we know is sometimes different from what werecapable of doing at any given moment. This is often called the learning vs. performancedistinction.

After extinction, Pavlovs dogs temporarily didnt drool to the conditioned stimulus (CS). But aftersome time passed by, they drooled again. One way to understand this is that extinction didnt ridthem of the memory of the yummy food when they heard the buzzer; rather, it just caused them tonot perform (not drool) when they heard that sound.

There are other things besides extinction that can affect your performance. Perhaps you are tired:this is why your professors always tell you to get a good nights sleep before an exam. Perhaps a dogdoesnt salivate when it hears the buzzer because it isnt hungry at that moment. Motivation is alwaysan important component of performing well, whether youre a dog or an Olympic athlete. Perhaps,at any given moment, you simply get confused between two memories. Think of those dogs; theymight be a bit mixed up, because sometimes the buzzer meant theyd get food, and sometimes itdidnt. All of these things can mean that what you have learned is temporarily not able to affect be-havior. Another way of looking at all of this is that its hard to prove that you dontknow something.

After an experience, you are likely to learn something, but sometimes, you just cant remember whatit was, or you cant or wont change your behavior at that moment.

Conditioned Taste Aversion

When I was nine years old, I ate the corn-chip snack called Bugles for the first time at a Girl Scoutmeeting. I loved them: my mother would not buy them so they were special; they tasted good; andI liked that they were cone shaped so I could wear them on my fingers like long nails. But thatevening, I developed stomach flu and threw up all night. Now as a middle-aged adult, I still avoideating Bugles. What has happened here?

This special case of classical conditioning is called conditioned taste aversion. You learn to avoid aparticular food because of a previous unpleasant experience with it. Experiencing sickness after eat-ing a food, especially a new food, forms a powerful association (Figure 4.5). It is so powerful that it

works even though it breaks a lot of classical conditioning rules. First, it usually only takes one timeof food (the conditioned stimulus) and sickness (the unconditioned stimulus) being paired for a per-son to avoid that food in the future; usually the CS and US must be presented over and over for anassociation to happen. Second, hours of time can pass between eating the food and the sickness, yet

we will still avoid that food in the future; usually, temporal contiguity is required for an associationto occur. Finally, even if the food and sickness never occur together again, a person will continue toavoid the food; usually we would expect extinction to occur and that the association would disappear.


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Figure 4.5 Conditioned taste aversion

Why is conditioned taste aversion such a special case? The explanation has to do with evolution.There must be something hardwired into our brains to avoid foods that were followed by illness. Soeven though my logical mind tells me that Bugles might be junk food, but that they really cannotmake me sick or die, my animal brain is saying, Step away from the Buglesyou might die! Thismay seem overly dramatic for snack foods, but it ultimately serves an adaptive purpose.

The second underlying theme of this course is that B =f(P + E + PE). Where do you think thatthe behaviorists put most of their emphasis? If you guessed the environment, youre correct! Forexample, with classical conditioning, the response is transferred from one stimulus to another be-cause of environmental factorsthe two stimuli repeatedly occur close together in time. This is

what Pavlov thought and referred to as temporal contiguity. Do you think classical conditioning isthe only type of learning that is driven primarily by the environment? Do you think that your ownlearning is driven only by factors outside of yourself? Lets move on to another type of associativelearning and see what we think.


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Figure 4.7 Escape learning

Escape Learning

The example of using aloe vera gel in the diagram above is a great example of escape learning. Thebehavior of applying aloe increases because it allows you to escape from the painful burning sensa-tion. Here is another example from my life. Have you ever been to a party or social gathering andgotten stuck in a conversation with someone you didnt want to talk to? I can think of several timesthis has happened to my husband. When it does, we have developed a secret language so that he canflash me a sign across the room that means, Help! Get me out of this conversation, and I can comerescue him. This has happened many times over the years. Why is his behavior repeated? Because

when he flashes me the sign, he gets to escape from the unpleasant situation. That is why this typeof negative reinforcement is called escape learning. His behavior of making our secret sign increases(i.e., has been reinforced), because he gets to escape from an unpleasant situation.

Avoidance Learning

Another possibility with negative reinforcement is avoidance learning(Figure 4.8). In this case,the unpleasant thing doesnt even happen because you do a behavior that allows you to avoid italtogether. The figure below demonstrates how you can avoid having to deal with the pain of a sun-burn before it even happens by applying sunscreen before you go outside. The behavior of applyingsunscreen then increases in the future because you avoid a painful burn. For another example, think

back to my poor husband. In contrast to the previous example where he flashes me a sign to escapefrom an unpleasant conversation, when he notices someone in advance who he doesnt want to getstuck talking to, he does all that he can to avoid coming in contact with that person to begin with.Behaviors like sneaking into a different room, or quickly striking up a conversation with someoneelse near him whenever this undesired person walks by, are reinforced because he avoidshaving tointeract with this person at all, thus the name, avoidance learning.


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Figure 4.8 Avoidance learning

Punishment

But what if we want to get rid of a behavior? The only reaction that has this effect is punishmentand it appears in two forms (Figure 4.9). The first type of punishment involves giving or applyingsomething unpleasant or undesired to stop a behavior. This is known aspunishment by application.Did you ever have to write I will not chew gum in class 100 times when you were in school orget yelled at for crossing the street without looking both ways? Your parents may have reacted to

your bad behavior by giving you a spanking or by saying stern words to you. These are examples ofpunishment by application. The consequence of behaving in this way is that something unpleasantor undesired is applied to you to decrease the likelihood that you will behave this way in the future.

Figure 4.9 Punishment by application and by removal

Punishment can also come in another form. This second type of punishment,punishment by removal,involves taking away something pleasant or desired that is usually already there, again with the goalof stopping a behavior. When you were younger (or maybe even recently), your parents may havereacted to your bad behavior by taking away a privilege that you usually had. Maybe you usually went


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Phenomena of Operant Conditioning

All of these examples of learning through operant conditioning can also be called acquisition, a termyou learned earlier in this chapter. Likewise, if the animal or person quits responding appropriately,you can call this extinction. In the case of operant conditioning, extinction would occur if the rein-forcement from the environment stopped. However, depending on the schedule of reinforcement,this extinction may happen quickly or take a long time. Dont forget that there are other reasons that

the animal or person might not respond. For example, what if the chicken wasnt hungrywouldyou expect her to play Mary Had a Little Lamb for food reinforcement? Its not that she forgothow to play; she just wasnt motivated to play at that time.

Schedules of Reinforcement

Are we always reinforced for every behavior we emit? No, sometimes we must learn the rules forthe delivery of reinforcement, known as the schedules of reinforcement. The simplest schedule ofreinforcement is continuous. On a continuous schedule, behaviors are reinforced every time. So, forexample, a dad could have his child on a continuous reinforcement schedule if every time they goto the grocery store, the child gets to choose a candy bar. So, all the child has to do is show up at

the store with dad, and voila, she gets candy.

A more common schedule of reinforcement is called intermittentor partial. In these cases, somesort of rule, or schedule, has to be followed to get the reward. Sometimes, this rule has to do withhow many times a particular action must be performed; this is given the name of ratio. It would bea ratio situation if a child had to say please a certain number of times while at the grocery storebefore her dad would buy the candy bar. Other times, this rule has to do with how much time goesby after the child was reinforced for saying, please; this is given the name interval. It would be aninterval situation if a child had to wait until they had been in the grocery store for a certain amountof time to get the candy bar after saying, please.

These ratio and interval rules can either be fixed, meaning they are constant, or instead they can be

unpredictable, or variable. So for example, afixed ratioschedule would mean that the child has tosay, please, an exactnumber of times before she is given candy. On the other hand, a variable ratioschedule would mean that the child has to say, please, an unpredictablenumber of times before shegets candy. That means that sometimes she only says it once and gets candy; other times she hasto say it ten timesshe never knows for sure how many times it will take. As you might guess, the

variable ratio schedule would get the parent the most pleasesthe child never knows exactly howmany she has to say to get the candy, so she keeps trying.

Likewise, afixed intervalschedule would mean that the child has to wait an exactamount of timeafter seeing the candy to say please before her dad will buy her candy. She could say please earlier,but Dad would be unrelenting. On the other hand, a variable intervalschedule would mean that

an unpredictableamount of time has to pass after she sees the candy before saying please for herdad to buy her candy. This means that sometimes she only has to wait one minute, but other timesshe has to wait ten minutesshe never knows for sure how much time must pass. As you mighthave guessed, a child on either of the interval schedules would say, please less frequently becauseit all had to do with time. Figure 4.10 illustrates the typical response patterns seen with the fourbasic schedules of reinforcement.


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Figure 4.10 Schedules of reinforcement and response patterns

Different patterns of responding are produced by the four basic schedules of reinforcement. The predictable na-

ture of afixed-ratio schedule(the red line at far left) produces a high rate of responding, with a pause after the

reinforcer is delivered. The unpredictable nature of variable-ratio schedules (green) also produces high, steady

rates of responding, but with hardly any pausing between reinforcers. Fixed-interval schedules(orange) produce a

scallop-shaped pattern of responding. The unpredictable nature of variable-interval schedules(blue) produces a

moderate but steady rate of responding. (Based on Skinner, 1961.)

When we look at the extinction effect in these schedules of reinforcement, it might surprise youto learn that behaviors learned from a continuous schedule are easiest to stop. Remember that inoperant conditioning, extinction happens when the reinforcer is stopped. The child who was givencandy every single time she went to the grocery store is now told that will not happen again becausecandy is bad for her teeth. The first time or two her dad takes her to the grocery and she does not get

candy, she might fight him on it, but very quickly she will see that the jig is up. She has never had towait before, so quickly she realized candy will never happen again and she does not fight any more.

Instead, a child who had been on any of the intermittent schedules would have been used to waitingfor her candy bar, for either a certain amount of pleases to occur or a certain amount of time topass. So when her dad cuts her off from candy, she retains some hope that candy will come back.It is as if she is saying, Ive had to wait before, I can wait this one out. Because of this she wouldcontinue to fight and beg her dad for candy for a much longer time after the reinforcer has disap-peared. The variable schedules are the most difficult to extinguish because of the unpredictability.

There is always the hope that the next response might be the one that is reinforced.

Learned Helplessness

Operant conditioning also provides examples of why people might just give up in the face of harshpunishment. In the late 1960s, Martin Seligman performed an experiment (which would not beallowed today) on dogs to show why people might just give up after lots of misfortunes. In Selig-mans experiment, he designed a dog kennel that had electrodes attached to half of its floor. WhenSeligman would turn on the electricity to the kennel, the dogs would yelp and jump to the safe sideof the kennel. For a second group of dogs, Seligman put up a clear Plexiglas barrier in the kennel,so when the electricity was turned on, the dogs could not escape and had to endure being shocked.


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The most important part of the study came next: Seligman took down the Plexiglas barrier, butwhen the electricity was turned on, the dogs in the second group still did not try to escape the shock!The actual barrier had been replaced by a learned barrier in the minds of the dogs: earlier they hadlearned that they could not save themselves so now they didnt even try. Seligman applied this ideaof learned helplessnessto humans. How much punishment or abuse can a person take before they

just give up and dont take advantage of ways to save themselves? If this bums you out, rememberwhat you have learned about optimism and resilience; it is important that you feel a sense of control

over the situation in order to overcome learned helplessness.

PsychSim 5: Operant ConditioningTo view this material, refer to eBook.

4.2.4 Do We Have to Associate Things to Learn?

When you moved into your new dorm or apartment, you might have had some terrible nights ofsleep because your neighbors upstairs must be elephants having a rave with all the clomping andloud music that you endure every night. Now weeks later that nightly noise continues, but you sleepsoundly. One night a friend crashes at your place and says, How can you stand all this noise? Youreply, I guess I dont notice it anymore. What is going on here?

This type of learning is called habituation and is the result of repeated exposure to a single

stimulus. It occurs without forming associations between stimuli and is referred to as a type ofnonassociative learning. Habituation explains how we react less and less, until we eventually dontreact at all to things that are very common in our lives. Our brains start to tune out things that seemunimportant because they arent changing. We have learned that we dont need to respond to themanymore to adapt to our environment.

Habituation might be useful in some circumstances such as when it helps us get used to new sur-roundings. You are able to sleep through your neighbors noise; your habituation allows you to getthe rest you need. On the other hand, habituation can cause us to miss important information.

Your alarm clock rings every morning, so eventually you habituate to its loud noise and sleep rightthrough it, missing your 9:00 class!

What about those times when the single stimulus becomes more and more annoying over time?What if, instead of habituating to the noise from your neighbors, now even the sound of theirfootsteps keeps you awake? This type of nonassociative learning is known as sensitizationand alsooccurs as the result of repetition of a single stimulus. Sensitization, like habituation, can be veryadaptivean exaggerated response to an extreme stimulus might help us stay alive.


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Concepts in Action: Banduras Bobo Doll ExperimentTo view this material, refer to eBook.

4.3 MEMORY

4.3.1 What Is Memory?

Memoryis commonly thought of as the process of forming memories, storing those memories, andlater being able to recall the information. For memory to occur, you must first take informationin from the environment, process it, and integrate it in your brain. For example, as you look at a

beautiful piece of art for the first time, your eyes take in the information and your brain converts itinto a kind of codethe process of transductiondiscussed in Chapter 3. Next, you need to create apermanent record of this information. For example, you might store a list of the objects or colors inthe painting, or the name of the painting, the date it was created, or remember the music that wasplaying or the date you were on when you saw it at the museum. Finally, at some point in the future,

you want to be able to recall that information when you need it. This happens, for example, whenyou come across the artists name again or hear the song that was playing and you are reminded ofthe painting.

Although various models of memory have been put forth by psychologists and neuroscientists, wewill concentrate on the information-processing modelof memory. This model conceives of memoryas a computer-like system with information being entered (encoding), then retained (storage), and

later being accessed (retrieval) when needed (Figure 4.11).

Figure 4.11 The information-processing model


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4.3.2 How Do I Create Memories?

In order to create memories, the first step is to go through the process of memory encoding. In thissection, we will discuss a model for how this encoding is thought to take place, the stages through

which information travels in order to become encoded, first briefly and then more permanently, andthe active role you need to take in order to make this encoding happen.

Figure 4.12 The stage model of memory

As depicted in the stage model of memory (Figure 4.12), memory consists of three stages or store-houses. First, information enters into sensory memory. This stage of memory is like an entry portalthat captures a stimulus ever so briefly as we decide whether or not we need to pay attention to it.

When you see something and look away, for a split second your mind retains an exact replica ofthe image. Similarly, when you hear something, for a brief moment, an echo of the words or soundrings in your ear before it fades. Information in the sensory register lasts only a fraction of a second

for visual stimuli and 24 seconds for auditory stimuli, and then either passes on to the next stageof working memory or it disappears.

Research has demonstrated the amazing capacity and accuracy of sensory memory. In a classic ex-periment, George Sperling (1960) presented participants with an array of up to 12 letters (Figure4.13). These arrays were flashed on a screen for between .05 and .50 msec. Immediately after thearray disappeared, participants were required to report what they saw. Regardless of the amount oftime they had or the number of letters presented, participants were only able to report about 4.5letters from the array after this very brief presentation. Does this mean that they only had time toencode between four and five letters during that time?


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Figure 4.13 Sperlings experiment demonstrating the capacity of sensory memory

In George Sperlings (1960) classic experiment, (1) subjects stared at a screen on which rows of letters were pro-

jected for just one-twentieth of a second, then the screen went blank. (2) After intervals varying up to one second,

a tone was sounded that indicated the row of letters the subject should report. (3) If the tone was sounded within

about one-third of a second, subjects were able to report the letters in the indicated row because the image of all

the letters was still in sensory memory.

Sperling believed that participants were really encoding more information, but by the time theystarted reporting the letters, the memory of them had already begun to fade. To test whether par-ticipants were really capturing more, Sperling again presented the array of letters, but this time onlyrequired participants to report part of what they saw. He would present a full array, and immediatelyupon removing it, he would sound a tone that let participants know whether they should report thetop, middle, or bottom row. He reasoned that if participants could report any row accurately andthey did not know which one they would have to report ahead of time, then they must initially en-code the whole array. However, they only have time to report a portion of it before the full memorybegan to disappear. Amazingly, when tested using this partial reporting technique, participants were

able to accurately report any row in the array, demonstrating that the capacity of sensory memoryis quite large, but its duration is extremely brief.

Information doesnt always disappear after it enters the sensory stage. Often we continue to thinkabout it and use it, moving it into our working memory. The working memoryregister retains infor-mation for about 20 to 30 seconds, which is why it is sometimes referred to as short-term memory.

This stage is extremely useful as a holding place for information. When you hear a phone number,for example, you are able to hang onto it long enough to write it down or enter it into your phone.

Working memory, however, is extremely limited in the amount of information it can hold at onetime. Its capacity is about 5 to 9 units of information. You have likely experienced the limits of thisstorage system. If someone read you two phone numbers and you had to enter both of them into

your phone, do you think you could do it?


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Lets see how many numbers you can remember in working memory.

Concepts in Action: Short-Term Memory CapacityTo view this material, refer to eBook.

How many were you able to remember? About seven, give or take one or two? What did you do to tryto remember the list? If you are like most people, you probably repeated the numbers over and overto yourself until you were able to write them down. This process is known as maintenance rehearsal.

We can retain information in this working memory stage as long as we continue to think about itactively, which is why this register is called workingmemory. Once you stop thinking about it, un-less you have processed it thoroughly enough, it will fade away. You can think of working memory

kind of like your arms when you are trying to carry things from your car into the house. Just as youcan only hold about seven units of information in your mind, you can only load your arms with afew items before you start dropping them. These items are right in front of youyou can see them,use them, workwith them, until you put them downjust as you can maintain information in your

working memory until you stop thinking about it.

Information that isprocessed deeply, however, will move intolong-term memory. This is the col-lection depot for everything from your mothers name to the night of your high school graduation.Unlike the sensory and working memory registries, long-term memory is unlimited in its capacityand can hold information indefinitely. Notice that in Figure 4.12, the arrows go both directionsfrom working memory to long-term memory. You can practice information to retain it in your

long-term storage and you can recall information and bring it into working memory to apply it in acurrent task. When someone asks for directions to your house, you are pulling this information outof long-term memory into working memory as you actively engage with it. Long-term memory islike a bottomless closet in your house that you can use to store all those items you carried into yourhouse from the car. You can go to that closet whenever you want to find what you need, and pull itout to work with it or share it with someone else.

So according to this stage model memory, information enters into sensory memory, either disap-pears almost immediately or is rehearsed and utilized by means of your working memory, and thenis either lost or practiced enough that it winds up in your permanent long-term memory storage.

But, have you ever had the experience of driving somewhere and, once you arrive, you cant remem-ber anything about the ride? Sound familiar? Why does this happen? You must have been encodinginformation about what was on the street and whether the lights you passed were green or red since

you arrived safely, but the question is, how much attention were you allocating to everything? Whenwe engage in tasks with which we have a lot of practice, we frequently use automatic processing. Thistype of non-conscious processing, which occurs without awareness, happens when we do somethingso routinely that we do not need to dedicate a large amount of cognitive resources to it. If you areable to carry on a conversation with someone while simultaneously tying your shoe, then you areengaging in automatic processing.


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Other times, however, the processing of information requires conscious, focused attention. You haveprobably noticed how your attention changes when you encounter road construction or heavy trafficand you dohave to concentrate and fully attend to the situation. This is known as effortful processing.

While you might be able to talk while you tie your shoe, unless you are an accomplished pianist, youprobably would have a great deal of difficulty trying to carry on a conversation while simultaneouslyplaying the piano. The less skilled we are at something, the more conscious attention it requires.Likewise, the more similar two tasks are, the harder it is to try to split our attention. It would sound

ridiculous if I asked if you could play the piano and read a book at the same time. Likewise, youare not capable of watching TV while studying a book and fully extract information from both thetelevision show and the text because these activities both require you to process different streams oflanguage and visual information at the same time.

As described in the previous examples, automatic processing affects later recall ability. If you do notconsciously focus and attend to something as you experience it, you will likely not be able to recallit later. Keep this in mind the next time you are in class and you reach to pull out your cell phone tocheck a text. It is called effortfulprocessing for a reason. The more effort you put into it, the moreeffective it will be.

4.3.3 How Do I Store Memories?

The process of memory storageallows us to save information in our long-term memory storehousefor later use. This section will discuss the different types of memories that we store and provideseveral examples of each type.

There are two general types of memory that we hold: explicit and implicit (Figure 4.14).Explicit memoryis memory that we can consciously recall and overtly declare. In fact, it is sometimescalled declarative memorybecause we can put it into words. Explicit memory is divided into semanticmemories and episodic memories. Semantic memoryincludes all of the facts and general knowledgethat you have accumulated over time. For example, if I asked you, what is your birthday? or what

is the capital of California? or what is text-speak for laughing-out-loud? I would be tapping yoursemantic memory. The second type of explicit memory is episodic memory. This includes all personalexperiences from your history. It is known as episodic memory because you can recall these eventsand picture them in your mind much like an episode of a television show. If I told you about myprom night or the birth of my first child, I would be accessing episodic memories.

Figure 4.14 Types of long-term memory


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In contrast to explicit memory, implicit memoryis not easily put into words and is recalled withoutconscious effort. One example of this type of nondeclarative memoryis procedural memoryor yourmemory for how to do things like how to tie your shoe, how to bake bread, or how to shoot a bas-ketball. If you have learned how to do these things, you can demonstrate your knowledge of them,but you would likely have difficulty putting them into words.

Implicit memory also includes conditioned responses like those you learned about earlier in this

chapter. If you automatically feel a little afraid when you hear theme music from a scary movie, orfeel anxious whenever you walk by the Psychology testing lab, these are implicit memories. A thirdtype of implicit memory is priming. Priming occurs when you are presented with a stimulus, a wordfor example, which primes or prepares you to respond a certain way in the future. For example, if

you are presented with a list of words that includes the word apricot and are later asked to nameseveral fruits, the probability that you will say apricot is higher because that word has been primedin your mind.

Concepts in Action: Long-Term Memory SubsystemsTo view this material, refer to eBook.

This example of priming also helps you to understand one of the models proposed for how informa-tion is represented in the mind. The semantic network modelsuggests that we store concepts in ourminds by connecting them to other related concepts (Figure 4.15). When one concept is activated,either by you seeing, hearing, or thinking about it, other related concepts become active as well. So

for example, the concept red exists in a network, known as a cluster, connected to related concepts,which might include other colors like blue or orange, as well as things like fire truck or stop-light. When you think of red, other concepts become activated or primed in your mind as well.


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of chunking like putting items into bags. This lets you carry more at one time. Instead of carrying acarton of milk, a bag of bread, and five oranges, you can toss all of this into a grocery bag and carry

just one item. This is like one chunk. Grouping information together is a quick way to improveyour storage capacity. Look at the individual units of information in Figure 4.16 and try to think ofways you could create chunks.

Figure 4.16 Examples of chunking

Our ability to recall information is also affected by the way the information is presented to us. Forexample, with chunking, if I told you to memorize the letters p, l, p, a, and e it would be easier if Ipresented the information in a different fashion as apple. Instead of five individual letters, you nowonly have one word to remember. Likewise, the order in which information is presented affects what

we recall. We tend to be better at remembering information at the beginning of a list and at the endof a list, while information in the middle tends to be more prone to memory loss. This is known astheserial position effect. The reason we do well for items at the beginning of a list is because we havethe most time to remember them and because when they are presented there is no other compet-

ing information that has been given to us yet. This is known asprimacy. The items at the end of alist are often easy to recall because they are the most recent in our minds. This is known as recency.

Concepts in Action: Serial Position EffectTo view this material, refer to eBook.

Memory Tip #2

The next time you are studying for an exam, mix things up. If you use

flashcards, do not always study them in the same order. Likewise, mix

up the order of subjects. Dont always study for your classes in the same

order each time.


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Another way that presentation affects memory is demonstrated by the encoding specificity principle.According to this principle, the way information is encoded affects later recall. There are variousexamples of this principle. First, recall our discussion of the benefit of having strong retrieval cues.It is often easier to remember something when we have a good cue to spark our memory. However,the cue must be both a strong cue and it must be a cue that we used when we were originally encod-ing the information. In one study (Tulving and Thomson, 1973), participants were given a list of

words to remember and the experimenter read off a list of cue words to help the participants com-

mit the list to memory. For example, if the word bank was on the list, the word money mightbe provided as a cue. During recall, if the word money was said, this would be a cue for the wordbank. However, the word river could also be considered a cue for the word bank if you imaginethe bank of a river instead of a kind of financial institution. Participants did much worse at the recalltest if the cue read during recall did not match the cue given during encoding.

Another example of the encoding specificity principle isstate-dependent memory. Our memories areaffected both by the environment and the emotional state we are in when we encode the informa-tion. In a famous study (Gooden and Baddely, 1975), researchers gave scuba divers a list of words toremember. Half of the divers studied the list on land and half of them studied the list underwater. Ifthe participants studied underwater, their memories were strong if they were also tested underwater.

Similarly, those that studied on land did well if they were also tested on land. In contrast, partici-pants did much worse if they studied in one place and were tested in another. Performance sufferedfor those that studied underwater and were tested on land and likewise for those who studied onland and were tested underwater.

Emotional state also affects recall. If you are in a pleasant mood, you are more likely to recall pleas-ant memories because you were in a positive mood when you encoded them. Likewise, if you arefeeling unhappy or angry, you will be more likely to easily recall negative or unpleasant memoriesbecause your mood at encoding and retrieval match.

Memory Tip #3

Try to study in the same kind of environment you will be in when you aretested. If you take exams sitting at a desk in a classroom, then you should

study sitting at a desk as well and not lying down on the couch or in a bed.

Also, try to put yourself in the same emotional state when you are tested

that you were in when you studied. Oftentimes we get nervous before an exam. This makes

things even worse because not only does anxiety affect recall, but you were likely relaxed

when you were preparing for the exam because you were in the comfort of your home and

there was no immediate concern about your performance. Before entering the room where

you will take an exam, take a moment to relax. Breathe deeply and try to mentally go back

to the place where you were when you studied.

The way you organize information, the context in which you study, and the mood you are in can allhave some impact on your recall. However, if you really want to improve your retention of material,

you need to think about the way you study it.

What techniques do you usually use to study for an exam? Do you use different techniques if you aretrying to memorize a phone number or grocery list? Sounds like a silly question, right? Nevertheless,all too often I find that many students take the same approach for these tasks without really real-izing it. To memorize a phone number or grocery list, most people would likely repeat the numberor food items over and over to themselves. Similarly, the most common study techniques I hear


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from students is that they read the chapter several times, perhaps also look over class notes, andmake flashcards of the bold terms in the chapter. These methods for the phone numbers, groceryitems, and class material are all taking the same approach and that is processing the material in a

very superficial, surface-level fashion. Memory researchers refer to this asshallow processing. Sim-ply looking at something repeatedly or saying something over and over is a form of maintenancerehearsal, which we discussed earlier as a good way to keep information in your working memory.

This technique, however, is not good at transferring that information into your long-term memory

storage. In order to preserve information for an extended period of time and ensure quality under-standing, it is necessary to use deep processing. Deep processing requires you to penetrate the surface,and to think about the meaning of the information you are trying to commit to memory. This isthe truest form of elaboration.

To use deep processing, think of examples for the concepts you are studying, try to define the con-cept in your own words, consider their meaning, visualize it, and apply the concept to yourself. Thisfinal technique of applying the concept to yourself is known as the self-reference effect. Research hasshown that we are much more likely to remember things if we can relate them to ourselves. All ofthese methods work regardless of whether you are trying to learn a complex concept for an exam orif you are trying to memorize a list of items to get at the store. If you are trying to remember what

positive reinforcement is, you will be more likely to remember it if you can think of a time that youexperienced it and if you bring up a mental image of that situation. Likewise, if you want to remem-ber to get mangos at the grocery store, you will be more likely to remember them if before you go,

you picture yourself standing in the produce section, biting into a mango and letting the juice dripdown your chinthe more detailed and bizarre the image, the stronger the memory.

Memory Tip #4

Process information deeply, think of examples, visualize concepts, and in-

corporate yourself into the image. The more peculiar the image, the more

likely you will be to remember it.

Another study technique that takes a bit of foresight isspaced practice. You are more likely to remem-ber something if you study several times over several days than if you engage in massed practice ortrying to cram all your studying into one long session. In addition to just spreading your studyingout over several days, you should also not study one subject for more than about one hour in a singlestudy session. Your studying will be much more effective if you study one subject for 45 minutes,take a short break, and then switch to an unrelated subject for the next 45 minutes. Then you caneither go back to the first subject or switch to a third subject.

Memory Tip #5

Extend your study sessions over several days or weeks. Study each subject

for only a short period of time and then switch to a new subject.

In addition to remembering material for classes, another type of memory that many people strugglewith on a daily basis is prospective memory.Prospective memoryis memory for things in the future,that is, remembering that you are going to have to do something. For example, remembering to pickup your dry cleaning on the way home, or when to take out the garbage, or when you have a doctorsappointment. All of these tasks require prospective memory. One of the reasons that people often


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struggle to remember these types of tasks is because many times they are not tied to a specific event,so there is nothing to cue your memory. These kinds of time-based events, like remembering that

you have to take a medication at 8 AM or that you have an assignment due on Thursday, are chal-lenging, but memory for them seems to improve if you can create a distinctive cue or event aroundthem. If you have to take a medication in the morning, you are more likely to remember it if you linkit to an event that you already do in the morning that is part of your routine. If you place the bottleof pills next to your toothbrush this will serve as a reminder when you brush your teeth. If you have

an assignment due in the future, set an alarm to go off in your phone or electronic calendar the daybefore it is due. What are some prospective memory tasks that you struggle to remember? What aresome ways that you could improve your prospective memory? See Table 4.2 for other useful tips onhow to improve your prospective memory.

Table 4.2 Ten Suggestions for Avoiding Prospective Memory Failure

1. Make reminder cues DISTINCTIVE and make sure that theytell you whatyou are supposed to remember to do.

2. Make reminder cues obviousby posting them where you willdefinitely see them.

3. Be proactive! Create a reminder the instant you realize that youneed to do something in the future.

4. Put a notepad or Post-it notes and a pencil inlots of convenient places (e.g., you dresser, yourcar, the kitchen counter, etc.).

5. For things you need to remember to do in thevery near future, buy small battery-operatedkitchen timers. (Yes its true. We have seventimers scattered throughout our home offices.)

6. Leave yourself a voicemail message with the re-

minder at home or at work.

7. Buy a pocket calendar or daily planner and use it!

8. Use the calendar reminder and follow-up featureson your computer or use a free Internet reminderservice (e.g., www.memotome.com).

9. If youre a Mac person, check out the reminder wid-gets. If youre a PC person, you can download the free3M Post-it Notes Lite software.

10. Get in the habit of making and updating a to-do list.

4.3.6 Do I Ever Really Forget?

I completely forgot. I have a terrible memory. I forget things all the time. I always forget peoplesbirthdays. That story is long forgotten. I have no memory for that at all. Do any of these phrasessound familiar? It seems as though forgetting is extremely common. At other times, you have prob-ably had the experience of thinking that you forgot something only to remember it later. So thequestion is, do we ever really forget?


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The answer may surprise you. In this section, we will discuss theories offorgettingincluding pro-posals that time makes you forget versus the idea that competing information causes interference.

We will also discuss motivated forgetting and why we seem to forget things from the earliest yearsof our lives.

Using himself as a subject, Hermann Ebbinghaus (1885) explored the nature of forgetting. Hememorized a long list of nonsense syllables like WID and ZOF. Once he had the full list memo-

rized, he tested himself at increasingly longer intervals to determine how time affects memory.Ebbinghauss results are depicted in Figure 4.17 in what is known as theforgetting curve. As youcan see, when you learn something, there is initially a large reduction in the amount of informationthat is remembered. However, after this big drop, the curve tapers off, and forgetting is much moregradual until we are left with the material that we retain indefinitely. What can we learn from this?

Without repeated conscious review, we will forget about 50% of learned material within a matter ofa few hours or days. In order to retain information in long-term memory indefinitely, we need toreview it regularly. You likely have experienced effects similar to Ebbinghaus from a class you tookin the past. Students often claim that they studied and studied for the final exam, did very well, andthen forgot everything by the next day. Months later, there are probably a few facts from the classthat stick out in your mind, but the majority of information has been lost.

Figure 4.17 The Ebbinghaus Forgetting Curve

Ebbinghauss research demonstrated the basic pattern of forgetting: relatively rapid loss of some information, fol-

lowed by stable memories of the remaining information.

Source: Adapted from Ebbinghaus (1885).


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Do you know what a penny looks like? Havent forgotten, have you? Take a look at Figure 4.18 andsee if you can pick out which is the true penny.

Figure 4.18

To view this material, refer to eBook.

Not as easy as you thought, is it? Why is this task so difficult? You have likely looked at penniescountless times in your life. How is it possible that you cannot pick one out of a line-up? This well-known task demonstrates the all too common problem of encoding failure. Many times, when wefeel as though we forgot something, the problem is really that we never encoded the informationto begin with. It is not that you forgot what a penny looks like. The issue here is that you prob-

ably never took the time to study and commit to memory the details of the penny. Have you everhad the experience of glancing at a clock, looking away, and a moment later thinking, Wait, whattime is it? What about being introduced to someone new and seconds later realizing that you cantremember the persons name? Sound familiar? Again, the issue here is not that you have forgottenthe time or the persons name, but that the information never even made it past the first step in theprocess of memorythat of encoding. As we discussed in previous sections, proper encoding re-quires conscious attention and effortful processing. To demonstrate this, Marmie and Healy (2004)gave people an unfamiliar coin for various time intervals. After only 15 seconds of exposure to anew coin, participants were better able to identify its features than they were at identifying those ofthe common penny. Next time you are trying to remember something and find that you are havingdifficulty, ask yourself, did I ever really learn it to begin with? Which reminds me, where exactly

did I park my car this morning?

Sometimes, of course, we do get past that first stage of memory and truly encode information, buteven then, we still have trouble remembering. Two theories exist for how and why forgetting oc-curs. The first idea is known as decay theory. According to this view, over time, memories beginto fade away as a result of natural metabolic processes in the brain. If memories are not reviewedand refreshed, then the memory trace, the structural or chemical change that occurred in the brainto create the memory, breaks down. Intuitively, this theory seems to make a lot of sense; however,think about some of the things that you remember and the kinds of things you forget. Do you re-member what you had for breakfast two weeks ago Thursday? Do you remember your high schoolgraduation? If memories simply decayed over time, then experiences that occurred a long time ago

would be more susceptible to decay than those that happened more recently. But this certainlydoesnt always seem to be the case. Additionally, as you can see in the forgetting curve, there is nota constant degradation of memories over time. Memory decline tapers off at some point and someinformation is retained indefinitely.

The evidence instead seems to support interference theory, which suggests that information is notforgotten, but it is difficult or impossible to access because it competes or interferes with existingmemories (Figure 4.19). There are two kinds of interference.


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as a defense mechanism. Some controversy developed around the issue of repressed memories whenit was discovered that some so-called repressed memories of sexual trauma turned out to be falseaccusations. While strong evidence exists from research on trauma and post-traumatic stress thatindividuals often do block out painful memories, it can also be difficult to assess whether something

was a real memory, that has been unknowingly repressed, or whether it never happened to beginwith. If an individual has no conscious recollection of the occurrence, then it can be difficult orimpossible to ascertain whether or not it actually ever occurred. We will discuss more on the fragile

nature of memory in the next section.

Freud was also well known for being the first psychologist to identify the phenomenon ofinfantile amnesia, or the general inability to recall events from approximately the first three yearsof life. Freud believed that this was a result of repressing early frightening experiences, particularlysexual ones. While subsequent research has indeed found that individuals typically do not recallevents prior to age three, various alternative explanations have been proposed. A significant amountof evidence suggests that the infant brain is not fully mature. The hippocampus and frontal lobes,

which play a large part in memory formation and consolidation, are not fully developed. Anotherlikely cause of the limits of early memory is the limited language abilities of infants and youngchildren. Unless they are able to put their experiences into words, they will be unable to retain the

information. Additionally, several theorists suggest that until around three and a half, children lackthe ability to fully understand what is happening in the world around them, which inhibits fullprocessing and retention of events. Finally, infants lack both a fully developed sense of self or anunderstanding of themselves as separate from others. All of these factors may contribute to youngchildrens inability to create lasting personal memories until reaching age three or four.

4.3.7 Does My Memory Make Mistakes?

Although it often seems like we can be transported back to a past time or place by replaying amemory in our minds, our memories are extremely fragile and are very susceptible to error anddistortion. There are various types of memory errorsthat we experience. In this section, we willdiscuss the kinds of mistakes that we make, what can cause them, and whether certain memoriesare immune to distortion.

Elizabeth Loftus, in several seemingly devious studies, demonstrates the delicate nature of memory.In one well-known experiment (Loftus and Pickrell, 1995), she brought adult participants intothe lab and talked to them about events from their childhood. The experimenter described severalevents that had been shared with the lab by the parents of each participant. In addition to variousactual events from their childhood, the experimenter also constructed a scenario of the participantbeing lost in a mall. The description included the participant getting lost for an extended period oftime, crying, being helped by an elderly woman, and being reunited with the family. Immediatelyafter it was described to them, over 25% of participants claimed to either partially or fully remember

the event happening and continued to remember the event occurring at a follow-up test two weekslater, even though it had actually never happened! These and other experiments demonstrate howeasy it is to create afalse memory. Think it cant happen to you? Complete the Concepts in Actionexercise before you continue.


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Concepts in Action: How Reliable Is Your Memory?To view this material, refer to eBook.

Did you experience a false memory? If so, dont worryyou arent alone!

There are several things that can contribute to the formation of false memories.Imagination inflationis one of the causes of the false memories experienced by Loftuss experimental participants. Whenthe fabricated scenario was described to the participants, they started to imagine the event occurring.Over the weeks between the initial description and the follow-up test, they may have continuedto visualize the scenario which only made the idea seem even more probable in their minds whenthey were later tested again. Imagination inflation is related to the experience ofsource confusionorforgetting the origin of a memory. Have you ever told a friend a joke only to have her reply, Yeah,I told you that joke? This is a common example of source confusion. Misinformation, or beinggiven false or misleading information, also creates memory distortion. Numerous studies have beenconducted demonstrating how information provided after an event can impair or even change amemory. Amazingly, it is not even necessary to provide false information to alter a memory. In an-other study, Loftus and Palmer (1974) showed participants a car accident and later questioned themabout details of the event. Some participants were asked, How fast were the cars going when theycontactedeach other? while others were asked, How fast were the cars going when they smashedeach other? Astonishingly, there was almost a 10 mph difference in the rates of speed reported.Participants have remembered stop signs, broken glass, and weapons that were never present in theoriginal scenarios, demonstrating the unstable and unreliable nature of memory.

Our memories are unstable. Every time we remember something or retell a story of a past event, wechange it a little. Some details are left out while others, that we may originally have been unsure of,are inserted. The more you retell a memory, the more prone it is to intrusion and alteration. Recallthat we described long-term memory as a storage closet. In that closet, you might store differentclothes. Each time you pull something out of the closet, a favorite sweater, for example, you wear itand it changes a bitmaybe you spill something on it and it gets a small stain or perhaps it gets asnag or develops a small hole. It never goes back into the closet the same way it came out.

Certain memories, however, seem immune to distortion. Where were you when you heard aboutthe September 11th attacks? Can you remember it like it was yesterday? If you close your eyes, can

you just picture it in your mind? How confident do you feel in the accuracy of those memories?Memories for these kinds of special, emotionally-charged events are known asflashbulb memories.

As the name indicates, it seems as though we experience them as exceptionally vivid snapshotsfrom our past. However, this characterization may be misleading. As with any memory, we do notstore an exact replica of an event. Memory is all about perspective and is also subject to error anddistortion. Individuals typically do report being highly confident in the accuracy of their memoryfor these flashbulb events. Research, however, is mixed regarding whether this type of memory isdistinct and less susceptible to distortion. Some research indicates that because we think about andretell the stories of these flashbulb memories more often, they are better recalled because of this


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rehearsal. In addition, the emotional nature of these experiences may contribute to a heightenedsense of confidence and improved retention. Other studies, however, have found that people are

just as likely to make errors or deletions in their retelling of these narratives as when they recall anyother episodic memory.

Video Tool Kit Activity: Creating False Memories: A Laboratory Study

To view this material, refer to eBook.

4.4 Neurobiology of Learning and Memory

4.4.1 What Is My Brain Doing When I Learn and Remember?

Although it was originally believed that little or no change occurs in the brain after birth, it is nowwidely accepted that the brain undergoes significant change throughout the lifespan. Nowhere is thismore apparent than in the study of learning and memory. What happens in the brain when we learn?

What about when we create and store memories? Neuroscientists believe that the brain changesboth its structure and how it functions as we learn and remember, and these changes occur not onlyin infancy and childhood, but throughout our entire lives. The flexibility the brain has in order tochange in response to the environment is known as plasticity. Learning and creating memories isall about the plasticity of the brain and its remarkable ability to create new connections and increasethe strength with which information is processed. In this section, we will discuss how and where

memories are stored in the brain, as well as what happens in the brain as we learn.

It is apparent from a great deal of research that a single learning center does not exist in the brain.Different types of learning involve different brain areas. For example, nonassociative learning (ha-bituation and sensitization) occurs due to changes in the sensory neurons themselves, as well aschanges in the central nervous system. Researchers have mapped out the neural pathways in thecerebellumthat are associated with classical conditioning, fear conditioning is associated with theamygdala, and reward learning involves dopamine neurons in the midbrain(Figure 4.20).

What about memory? Originally it was believed that each memory was localizedor stored in a par-ticular location in the brain, almost as though we could crack open your brain and point to the spot

that housed your memory for your first day of high school or the spot that contained the informationabout what you ate for breakfast this morning. To test this theory, Karl Lashley (1948) conducted aseries of experiments with rats. First, he had them create a memory for a maze by having them runthe maze over and over until they could find a piece of food hidden within it with ease. Lashley thentook individual rats and removed portions of their brains and had them run the maze again. Aston-ishingly, no matter which portion of the brain was removed, the rats still demonstrated memory ofthe maze. There was no single portion that could be cut out that caused them to forget the maze.

This led Lashley to conclude that memories are not localized to one place in the brain, but insteadare distributedthroughout the brain.


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Subsequent research has explored which particular areas of the brain are involved in the formationand storage of memories (Figure 4.20). The prefrontal cortex, the area under your forehead, is in-

volved in holding information for temporary storage in working memory. If that information is to beconverted into a long-term memory, the next area that is activated is thehippocampus, a sea-horseshaped structure that is part of the limbic system of the brain, which has been found to be one ofthe major structures involved in memory formation. As stated previously, memory formation takesadvantage of the brainsplasticityor ability to change. It is within the hippocampus that the majority

of the change takes place when a memory is formed.

Another area of the brain that has been found to be important for memory consolidation, or establish-ing memories over the long term, are the medial temporal lobes, which includes the hippocampusand surrounding structures. When a long-term memory is first created, the hippocampus is activated

which then activates various other structures in the brain. For example, your memory for a sunnyday at the beach may activate various sensory structures as you recall the smell of the coconut suntanlotion, the sound of the waves crashing and seagulls calling, and the taste of the salty water. Overtime, as the memory becomes consolidated, the hippocampus becomes activated less and less andthe memory exists only in the cortex in these sensory processing areas. The medial temporal lobesare the brain areas responsible for creating the links between these multiple brain regions.

Other important structures involved in memory are the amygdala, which processes emotional mem-ories, like when you recall the fear you felt when you nearly got in a car accident, the cerebellum,

which is active for procedural memories, like when you remember how to ride a bike, and thefrontal lobes, which are involved in autobiographical and episodic memories, like when you recallyour first kiss.


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Figure 4.20 Brain structures involved in human memory

Shown here are some of the key brain structures involved in encoding and storing memories.

We dont have note cards in our prefrontal cortex or an iPad in our hippocampus, so what is goingon in these various brain areas involved in learning and memory? As you learned in Chapter 2,thinking activates neurons. When a neuron is activated, it fires, causing it to release neurotransmit-ters into the synapse or space between neurons. When you experience something, multiple neuronsthroughout the brain become activated, processing that information, and allowing you to react.

The next time you are exposed to those stimuli or you review or recall the event, the same series orcircuit of neurons is activated. As the same neural circuitis activated more and more, the speed ofthe firing, the strength of the connection between neurons, and the amount of neurotransmittersthat are released all increases. This process is known as long-term potentiation. You can liken thisto what happens when your driveway becomes covered with snow in the winter and it is too cold togo out and shovel. Instead, you simply drive your car down the driveway and hope that youll makeit out. The first time, its rather slow and difficult as your car tries to make a path for the tires inthe thick snow. However, the more you ride over the same spot, the deeper the grove that is cre-ated until you can easily back your car out. Each time we learn an association or encode a piece ofinformation, the brain experiences both structural and functional changes. Along with changes in


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the activity of neurons (functional plasticity), there is also evidence that the number of synapses orconnections between neurons increases with learning and memory (structural plasticity). In fact,there is even evidence that new neurons can increase in the hippocampus with certain types of learn-ing and memory (Shors, et al., 2012).

4.4.2 What Can Go Wrong?

While it is always frustrating when we experience everyday forgetfulness, like when we just cantremember what we were about to say or when our next paper is due, there are a few seriousmemory disordersthat signal much more complex problems.

In discussing memory consolidation, we mentioned that over time, long-term memories that areformed in the hippocampus are transferred and stored in upper regions of the cortex. Sometimes,however, because of an illness or accident, this process of consolidation does not occur which leadsto retrograde amnesiaor loss of information learned before the time of injury. Several students

who have been involved in minor car accidents or experienced more severe injuries have often toldme about their inability to recall the event itself and often cannot remember things that happenedearlier in the day as well. This kind of retrograde amnesia is common following an accident. More

severe forms of retrograde amnesia in which individuals forget months or even years of their livesoccur as well, but are rare, and are more commonly caused by illnesses like a stroke or infection thatdamages structures in the brain.

Another form of amnesia is so intriguing that many movies have tried to depict what the experienceis like. Movies likeMemento, 50 First Dates, and Finding Nemoall have characters that have some-thing that resembles anterograde amnesiaor the inability to create new memories. Keep in mind,however, that most cinematic depictions of this memory disorder are quite distorted. Psychologistsfirst learned about this kind of amnesia in a man named Henry Molaison, known for years as H.M.

As a young man, H.M. suffered from severe epileptic seizures and because they were unresponsive tomedications, he underwent an experimental procedure in 1953 which involved removing the hippo-

campus on both sides of his brain. The surgery was successful in curbing his seizures, however, it haddevastating consequences. H.M. was no longer able to create any new memories of facts or events,and lived from that point on in what was termed the vanishing present. Another well-known caseof anterograde amnesia is that of Clive Wearing. Clive developed this memory disorder as a resultof viral encephalitis, a virus that causes inflammation in the brain. In Clive, this illness virtually de-stroyed the hippocampus on both sides of his brain, resulting in severe anterograde amnesia. Clive isunable to form new explicit memories. What is fascinating about this memory disorder is that uponfirst meeting individuals like Clive and H.M. they seem perfectly normal, their intellectual capacityis intact. However within one minute, the effects of the amnesia become immediately apparent.Both men can remember only the past 30 to 60 seconds or what is in their working memory. Notethat in movies this is often characterized as a loss of short-term memory, which is actually quite

the opposite. Individuals like Clive and H.M. have onlyshort-term or working memory, but havelost the ability to convert that information into a long-term memory.

Clive reports that he constantly feels like he has just woken up because he cannot remember anythingthat just happened. Much like the character in the movieMemento, Clive keeps a diary to try to re-cord events in his life. However, the diary is filled with entry after entry noting the time and stating,I am now awake - first time followed by an entry only minutes later again stating, I am NOWawake. Many statements have been crossed out throughout the book as Clive looks back and feelsthat he cou

Chapter 4 Learning and Memory

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