Learning, Language, and Thought: Lecture 1
PSYC 1301
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A child goes to the doctor for shots - she doesn't cry the first time until she gets the shots. The second time she starts to cry when she sees the doctor. Later, she begins to cry when she sees anyone wearing a white lab coat. Finally, she begins crying when she hears the word "doctor." So, what has happened? The child has learned to associate white lab coats with doctors and doctors with shots, which cause pain.
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Learning is simply the process by which experience or practice results in a relatively enduring change in behavior or potential behavior. In other words, learning means a reorganization of behavior. Learning involves making associations, formation of concepts, theories, ideas, and other mental abstractions.
The automatic shift of attention to something new is known as an orienting response. Once a person orients himself/herself to this new stimulus, habituation occurs. Habituation is generally regarded as the simplest form of learning.
Association occurs when one bit of information from the environment becomes linked repeatedly with another, and the organism begins to connect the two sources of information.
Conditioning is a form of associative learning in which behaviors are triggered by association with events in the environment. Someone sneezes and we respond with "God bless you." Someone says "how are you" and you respond with "fine, thank you, and you?" even if you are really feeling pretty lousy.
Classical conditioning is simply the type of learning in which reflexive behaviors that would automatically follow one type of stimulus are brought on by a different, previously neutral stimulus.
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Russian psychologist Ivan Pavlov is most closely associated with classical conditioning. He hit upon classical (or Pavlovian) conditioning almost by accident when studying digestive processes. He trained dogs to salivate at the sound of a bell by presenting the sound just before food was brought into the room. Eventually, the dog would salivate at the sound of the bell even though no meat was present. The unconditional stimulus causes a reflex action, which is the unconditional response. The conditional response is repeatedly paired with the unconditioned stimulus until, eventually, the conditional response occurs. |
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Pavlov called this type of learning the conditioning of reflexes. Today, we refer to this type of conditioning as classical conditioning. The unconditioned response (UCR) is the natural automatic, inborn response to a stimulus. In this case, unconditioned simply means unlearned. The unconditioned stimulus (UCS) is the environmental input that causes the unlearned, reflexive response. The conditioned stimulus (CS) is the previously neutral stimulus that the organism learns to associate with the UCS. Thus, the conditioned response (CR) is the behavior that the organism learns to perform when presented with the conditioned stimulus alone.
When the neutral stimulus is presented just before the UCS, or the neutral stimulus and the UCS are presented at the same time, forward conditioning occurs. Backward conditioning occurs when the neutral stimulus follows the UCS. Classical conditioning is more likely to succeed when the UCS and the CS are paired close together in time.
Stimulus generalization develops by extending the association between UCS and CS to include a broad array of stimuli. For instance, a person may develop a fear of all animals after he/she is bitten by a dog.
Extinction is a decrease in strength, frequency, or stopping of a learned response because of failure to continue pairing US and CS or withholding reinforcement.
For instance, your dog would come running into the kitchen expecting to be fed when he/she heard the electric can opener. The can opener breaks and you resort to a manual can opener. Months later you buy a new electric can opener. The dog does not come running when he/she hears the sound of the new can opener since the connection between the sound of the can opener and the food has become extinct.
Difficulty of extinguishing a conditioned response depends on the following:
Spontaneous recovery is the reappearance of an extinguished response after the passage of time without training.
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One of the best illustrations of stimulus generalization in humans comes from the research of John Watson and Rosalie Rayner in the conditioning of Little Albert. Little Albert was a nine-month-old infant who was conditioned to fear a white rat. Initially, he was curious about the rat, but he was not afraid of it. Then they would make a very loud noise by striking a steel bar with a hammer behind Little Albert at the same time that he was presented with the rat. Naturally, Little Albert was startled by the noise and upset by the rat. Rayner and Watson then generalized the fear to other stimuli including a rabbit, dog, white fur coat, and a Santa Claus mask.
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Click here for a clip of the Little Albert experiment.
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Watson and Rayner's experiment showed that fears can be conditioned, fears can be generalized, but such experiments may not be ethical by today's standards.
Humans also learn to associate certain sights or sounds with other stimuli. Using much the same principle, Mary Cover Jones developed a method for unlearning fears: she paired the sight of a caged rat, at gradually decreasing distances, with a child's pleasant experience of eating candy. This method evolved into desensitization therapy - a conditioning technique designed to gradually reduce anxiety about a particular object or situation. Recently, scientists have discovered that the immune system may respond to classical conditioning techniques, thus allowing doctors to use fewer drugs in treating certain disorders.
John Wolpe concluded that since much of our behavior is learned, there was no reason why it could not be unlearned. He first experimented with cats by giving them mild electric shocks accompanied by specific sounds and visual stimuli. Eventually the pairing created a feeling of fear. By gradually exposing the cats to the same sounds with food, the cats gradually unlearned their fear. Wolpe went on to show that therapy could be combined with other empirical methods.
Modern desensitization techniques include relaxation techniques in stressful situations until the patient/client is able to handle the fear underlying the stressful object or situation. If a person is afraid of dogs, he may be asked to look at a picture of a dog, pet a puppy, and eventually pet a large dog. Virtual reality has been used to give a person the feeling of actually being in the situation that causes the stress such as fear of flying.
Classical conditioning focuses on a behavior that invariably follows a particular event, whereas operant conditioning concerns the learning of behavior that operates on the environment: the person or animal learns from the consequences of its behavior. He/she behaves in a particular way to gain something desired or avoid something unpleasant.
Psychologist Edward Lee Thorndike was the first researcher to study operant behavior systematically. He used a puzzle box to determine how cats learn. A cat enclosed in a box struggled to escape and eventually moved the latch which opened the door. Each time the cat was placed in the box, it ceased to do those things that had proven ineffective ("errors") and soon made the successful response (move the latch) after being placed in the box. Thorndike summarized the influence of consequences in his law of effect: The consequences of a behavior will affect the likelihood of that behavior's being repeated. Behavior that brings about a satisfying effect is likely to be performed again. Moreover, the behavior would occur more quickly over time. Behavior that results in punishment is decreased.
Although Thorndike was a pioneer of operant conditioning, B.F. Skinner is probably the most well known, not only for his work with operant conditioning, but the development of operant conditioning into behavior therapy. He coined the term operant to refer to behavior that operates or acts on the environment to produce specific consequences. Skinner built a small cage with solid walls with a lever mounted on the wall. This box came to be known as the Skinner Box. He would place a bird or rodent in the box. Eventually the bird or rodent would learn to press a lever to receive food pellets. For a brief survey of operant behavior in Skinner's own words, go to http://bfskinner.org/
Although all reinforcers (both positive and negative) increase the likelihood that a behavior will occur again, punishment is any event whose presence decreases the likelihood that ongoing behavior will recur. Reinforcement always strengthens behavior; punishment weakens it. Primary reinforcers are innate and satisfy biological needs such as food for hunger, water for thirst. Secondary or conditioned reinforcers are learned by association. For instance, if I earn all A's, my parents will give me money.
Positive reinforcement focuses on the presenation of something, someone, or a situation as a reward for behavior. Negative reinforcement is the removal of an unpleasant stimulus that increases the probability of a behavior. Punishment, on the other hand, decreases the likelihood that the behavior will occur. This may occur through positive punishment or the addition of a stimulus that may increase behavior such as spanking to stop an undesirable behavior. Negative punishment, on the other hand, is the removal of a stimulus in order to decrease the behavior. An example of negative punishment would be taking a teenager's cell phone away for breaking a curfew.
Another way to speed up operant conditioning is through shaping, or reinforcement of successive approximations of the desired behavior. Avoidance training involves learning a desirable behavior that prevents an unpleasant condition, such as punishment, from occurring.
Despite their differences, classical and operant conditioning share many similarities. Both involve associations between stimuli and responses; both are subject to extinction and spontaneous recovery as well as generalization and discrimination. In fact, many psychologists now question whether classical and operant conditioning are not simply two ways of bringing about the same kind of learning. Biofeedback is an operant conditioning technique in which instruments are used to give learners information about the strength of a biological response over which they seek to gain control.
Social learning theory argues that we learn not just from firsthand experience, but also from watching others or by hearing about something. Enactive learning is learning by doing, whereas observational learning involves learning by watching others. Albert Bandura, the father of Social Learning, contends that observational (vicarious) learning accounts for many aspects of human learning. The primary method for this vicarious learning is known as modeling, or the process of observing and imitating behaviors performed by others. Such observational learning stresses the importance of models in our lives. To imitate a model's behavior, we must (1) pay attention to what the model does; (2) remember what the model did; and (3) convert what we learned from the model into action. The extent to which we display behaviors that have been learned through observation can be affected by vicarious reinforcement and vicarious punishment. Reinforcement experienced by a person that affects the willingness of others to perform the behavior they learned by watching the person is called vicarious reinforcement, whereas punishment experienced by someone that affects the willingness of others to perform the behavior learned by watching the first person is called vicarious punishment. Social cognitive theory emphasizes that learning a behavior from observing others does not necessarily lead to performing that behavior. We are more likely to imitate behaviors we have seen rewarded.
In the 1960s, Bandura did a series of studies incorporating a Bobo doll in which he demonstrated that children who viewed aggression were more aggressive with the doll than those who did not see aggression. For Bandura's description of this experiment, click here.
In 1961, Breland and Breland, two of Skinner's students, conditioned 38 different species and more than 6,000 animals. They coined the term instinctive drift which means that an organism will revert back to inborn behavioral tendencies if it learns a new behavior.
The biological constraint model of learning suggests that some behaviors found to be useful for survival are more likely to be learned than others.
Imprinting, imitation, synaptic change, and brain growth through enrichment all illustrate the importance of interplay between nature and nurture. Imprinting is defined as the rapid and innate learning of the characteristics of the caregiver within a short time after birth. Ethology is the scientific study of this type of animal behavior. Korand Lorenz is probably the best known researcher in this area through his work with ducklings and goslings. For a video clip showing Lorenz with the goslings in his experiment, click here.
Through studies on imprinting, we see the importance of sensitivity periods of learning in which animals exposed to a particular stimulus or situation will learn it very rapidly. Once the animal has moved beyond that period, it becomes harder. These sensitivity periods illustrate that the mind is not a blank slate but is structured so that certain experiences are more easily learned at certain stages. This allows toddlers and young children to learn language with a vocabulary of up to 10,000 words by the time they enter kindergarten. Perhaps this also illustrates why it is so much easier for a small child to learn a second language than an adult.
As we grow, the synaptic connections between neurons grow and change as we learn. So, not only does "practice make perfect", but "if you don't use it, you will lose it."
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