AP Psychology 3.7-3.8: Classical and Operant Conditioning

Negative reinforcement

Increasing a behavior by removing or avoiding an aversive stimulus after the behavior, such as fastening a seat belt to stop an irritating alarm.

Punishment

Any consequence that decreases the likelihood of a behavior recurring. Punishment is defined by its effect on behavior, not by whether it is physically painful.

Positive punishment

Decreasing a behavior by presenting or adding an aversive stimulus after the behavior, such as assigning an extra chore for breaking a rule.

Negative punishment

Decreasing a behavior by removing a desirable stimulus after the behavior, such as taking away a teenager's phone privileges.

Reinforcement

Any consequence that increases the likelihood of a behavior recurring. Reinforcement is defined by its effect on behavior, not by whether the consequence is pleasant to everyone.

Classical conditioning

A form of associative learning in which an organism learns to associate two stimuli and consequently anticipates an event. A previously neutral stimulus eventually elicits a learned response.

How does classical conditioning differ from an unlearned reflex?

An unconditioned reflex occurs naturally without prior learning, whereas classical conditioning creates a learned association between a previously neutral stimulus and an unconditioned stimulus.

Unconditioned stimulus (UCS)

A stimulus that naturally and automatically elicits a reflexive response without prior learning, such as food producing salivation.

Unconditioned response (UCR)

A natural, unlearned reaction to an unconditioned stimulus, such as salivation in response to food.

Neutral stimulus (NS)

A stimulus that initially does not reliably elicit the response of interest. Through repeated pairing with a UCS, it may become a conditioned stimulus.

Conditioned stimulus (CS)

A previously neutral stimulus that elicits a learned response after being repeatedly paired with an unconditioned stimulus.

Conditioned response (CR)

A learned response elicited by a conditioned stimulus, such as salivation to a tone that predicts food.

What is the sequence of Pavlov's classical-conditioning procedure before, during, and after conditioning?

Before conditioning: food (UCS) produces salivation (UCR), while a tone (NS) produces no relevant response. During conditioning, tone plus food produces salivation; after conditioning, the tone becomes a CS and produces salivation (CR) by itself.

Why did Pavlov conclude that salivation to laboratory footsteps was learned rather than reflexive?

Dogs naturally salivate when food is placed in their mouths, but they do not naturally salivate to footsteps or an empty bowl. The response developed because those stimuli became associated with food.

What does the temporal order of stimuli usually need to be for classical conditioning to develop effectively?

The CS or formerly neutral stimulus generally needs to occur shortly before the UCS. The optimal interval varies, but a brief gap is often important; taste aversion is an exception that can develop after several hours.

Acquisition

The initial phase of classical conditioning in which an organism learns the association between a neutral stimulus and a UCS. The CR typically becomes stronger with repeated pairings.

How does stimulus predictability affect acquisition of a conditioned response?

A CS is learned more readily when it reliably predicts the UCS. If the UCS occurs inconsistently after the CS, the association is weaker because the CS provides less useful information.

Rescorla-Wagner model

A model proposing that the strength of conditioning depends partly on how well the CS predicts the UCS and on the amount of prediction error. A reliably predictive CS gains stronger associative strength than an unreliable one.

Higher-order conditioning (second-order conditioning)

Learning in which an established CS is paired with a new neutral stimulus, causing the new stimulus to eventually elicit the CR. Conditioning beyond the second order is generally difficult.

In chemotherapy-related nausea, how are the chemotherapy drugs, vomiting, and the doctor's office classified?

The drugs are the UCS, vomiting is the UCR, the doctor's office becomes the CS after repeated pairings with treatment, and nausea in the office is the CR.

How does a syringe become a conditioned stimulus in a chemotherapy example?

The syringe, initially neutral, is repeatedly associated with the established CS—the doctor's office—and chemotherapy. It can then elicit nausea as a second-order conditioned stimulus.

Positive reinforcement

Increasing a behavior by presenting or adding a desirable stimulus after the behavior, such as giving a student praise for completing homework.

In a cat-food example, what do the cat food, salivation or excitement, and electric can-opener sound represent?

The food is the UCS, and salivation or feeding-related excitement to the food is the UCR. The can-opener sound begins as a neutral stimulus and becomes the CS, producing excitement as the CR.

Extinction

The gradual weakening and disappearance of a CR when the CS is repeatedly presented without the UCS. Extinction reduces the expressed response but does not necessarily erase the original learning.

What procedure would extinguish a cat's conditioned excitement to an electric can opener?

Present the can-opener sound repeatedly without following it with cat food. The cat's excitement should gradually decline.

Spontaneous recovery

The reappearance of a previously extinguished CR after a rest period. It shows that extinction does not completely eliminate the original CS-UCS association.

How are acquisition, extinction, and spontaneous recovery related over time?

During acquisition, repeated CS-UCS pairings strengthen the CR. During extinction, CS-alone presentations weaken the CR; after a pause, spontaneous recovery may cause the CR to return.

Taste aversion

A conditioned avoidance response in which an organism associates the taste or flavor of an ingested substance with later illness. It can develop after a single exposure and despite a delay of several hours.

Why is taste-aversion learning considered biologically adaptive?

Rapidly learning to avoid a flavor followed by illness can protect an organism from repeatedly consuming harmful food, supporting survival.

What did flavor-illness versus light-or-sound-illness experiments reveal about classical conditioning?

Rats readily learned to avoid a flavor paired with illness but generally did not learn to avoid lights or sounds paired with illness. This demonstrates biological constraints or preparedness in learning.

Stimulus generalization

The tendency to produce the CR to stimuli that resemble the CS. The more similar a stimulus is to the CS, the more likely it is to trigger the learned response.

Stimulus discrimination

Learning to respond to the specific CS but not to similar stimuli that do not predict the UCS. It allows an organism to make appropriate distinctions among environmental cues.

How are stimulus generalization and stimulus discrimination opposites?

Generalization spreads the CR from the CS to similar stimuli, whereas discrimination restricts the CR to the specific CS or to stimuli that reliably predict the UCS.

What did Little Albert's conditioning experiment demonstrate?

A previously neutral object, such as a white rat, became fear-eliciting after being paired with a loud noise. The case suggested that emotional responses can be classically conditioned.

In the Little Albert example, identify the UCS, UCR, CS, and CR.

The loud noise was the UCS, and reflexive fear or crying to the noise was the UCR. The white rat became the CS, and fear or crying to the rat was the CR.

What form of learning did Little Albert show when he feared a rabbit, furry coat, and similar objects after conditioning to a white rat?

He demonstrated stimulus generalization: the fear response spread from the original CS to stimuli resembling it.

Why would the Little Albert study be considered unethical by current standards?

Researchers intentionally conditioned fear in a child without adequate protection or demonstrated deconditioning, and the child could not provide informed consent. Modern research standards require stronger safeguards for human participants.

Behaviorism

A psychological perspective emphasizing observable, measurable behavior and environmental stimulus-response relationships rather than unobservable mental processes.

How did Watson extend Pavlov's ideas?

Pavlov demonstrated conditioning of reflexive responses in dogs; Watson argued that similar principles could explain conditioned human emotions, including fear.

How can classical conditioning explain some advertising effects?

An advertiser pairs a product with an appealing person or positive emotional cue. Repeated pairing can make the product itself elicit favorable feelings.

Why might an athlete's scandal reduce the effectiveness of an endorsement?

The athlete may no longer evoke the positive emotional reaction needed for conditioning. Pairing the product with a disliked or controversial figure could weaken or alter the intended association.

How does an invisible electric fence condition a dog's fear of a yard boundary?

The electrical shock is the UCS and discomfort is the UCR. After the shock is paired with the yard's edge, the edge becomes the CS and elicits fear or anxiety as the CR.

In the Stingray City example, how does a boat engine become a conditioned stimulus?

Food scraps and squid function as the UCS, naturally eliciting feeding behavior. After repeated pairings of boat engines with food, the engine sound becomes a CS that elicits anticipatory feeding behavior.

Operant conditioning

A form of learning in which behavior is influenced by its consequences. Behaviors followed by reinforcement become more likely, whereas behaviors followed by punishment become less likely.

How does operant conditioning differ from classical conditioning?

Classical conditioning involves learning associations between stimuli and often produces reflexive responses. Operant conditioning involves behaviors emitted by an organism and shaped by their consequences.

Thorndike's law of effect

The principle that behaviors followed by satisfying consequences are more likely to be repeated, whereas behaviors followed by unpleasant consequences are less likely to recur.

What is a Skinner box?

An operant-conditioning chamber containing a mechanism, such as a lever or key, that an animal can manipulate to receive a consequence such as food or water. It allows researchers to measure how consequences affect behavior.

How do positive and negative reinforcement differ from positive and negative punishment?

Reinforcement increases behavior, whereas punishment decreases behavior. Positive means that a stimulus is added; negative means that a stimulus is removed.

Primary versus secondary reinforcers

Primary reinforcers satisfy biological needs, such as food, water, or warmth. Secondary, or conditioned, reinforcers acquire their value through learning, such as money, grades, or praise.

Shaping

An operant-conditioning procedure that teaches a complex behavior by reinforcing successive approximations—behaviors that gradually become more similar to the desired behavior.

What are successive approximations?

Intermediate behaviors that progressively resemble a target behavior. In shaping, each approximation is reinforced until the organism performs the complete target behavior.

What is a discriminative stimulus in operant conditioning?

A cue signaling that a particular behavior is likely to be reinforced or punished. For example, a 'walk' sign signals that crossing behavior can be reinforced by safely reaching the other side.

Continuous reinforcement

A schedule in which every occurrence of a desired behavior is reinforced. It is useful when first teaching a behavior but can make the behavior vulnerable to extinction if reinforcement stops.

Partial or intermittent reinforcement

A schedule in which a behavior is reinforced only some of the time. Compared with continuous reinforcement, it usually produces greater resistance to extinction.

Fixed-ratio schedule

A reinforcement schedule that provides reinforcement after a set number of responses, such as receiving a bonus after producing every tenth item. It often produces a high response rate followed by a brief pause.

Variable-ratio schedule

A reinforcement schedule that provides reinforcement after an unpredictable number of responses, such as gambling or checking for a winning outcome. It produces a high, steady response rate and strong resistance to extinction.

Fixed-interval schedule

A reinforcement schedule that provides reinforcement for the first response after a predictable amount of time has passed, such as a weekly quiz or a paycheck every two weeks. Responses often increase as the expected time approaches.

Variable-interval schedule

A reinforcement schedule that provides reinforcement for the first response after an unpredictable amount of time has passed, such as checking for an unexpected message. It produces a steady, moderate response rate.

How do ratio and interval schedules differ?

Ratio schedules depend on the number of responses made, whereas interval schedules depend on the passage of time before a response can be reinforced. Fixed schedules are predictable; variable schedules are unpredictable.

Which reinforcement schedule generally produces the greatest resistance to extinction?

A variable-ratio schedule generally produces the greatest resistance to extinction because reinforcement is unpredictable and the organism tends to respond persistently.