Chapter 6: Classical Conditioning – Study Notes

Learning

Definition and Types

Learning refers to any relatively durable change in behavior or knowledge that results from experience. It is a fundamental process in psychology, underlying how organisms adapt to their environment.

• Phobias: Irrational fears of specific objects or situations, often acquired through learning processes.

• Superstitions: Behaviors that are repeated because they are followed by a reward or positive reinforcement (e.g., wearing a 'lucky' jersey after a win).

• Conditioning: The process of forming associations between events that occur in an organism's environment.

Classical Conditioning

Overview and Historical Background

Classical conditioning is a type of learning in which a stimulus acquires the capacity to evoke a response that was originally evoked by another stimulus. This process was first systematically studied by Ivan Pavlov (1849–1936), a Russian physiologist who discovered the phenomenon while researching the digestive processes of dogs. Pavlov observed that dogs would begin to salivate not only when food was presented, but also in response to stimuli associated with food, such as the sound of a bell.

• Pavlovian conditioning: Another term for classical conditioning, emphasizing Pavlov's foundational role.

Key Terminology

• Unconditioned Stimulus (UCS): A stimulus that naturally and automatically triggers a response without prior learning (e.g., meat powder).

• Unconditioned Response (UCR): An unlearned, naturally occurring reaction to the UCS (e.g., salivating in response to food).

• Conditioned Stimulus (CS): A previously neutral stimulus that, after being paired with the UCS, elicits a conditioned response (e.g., a tone).

• Conditioned Response (CR): A learned response to the conditioned stimulus that occurs because of previous conditioning (e.g., salivating to the tone).

Sequence of Events in Classical Conditioning

The process of classical conditioning typically unfolds in three stages:

• Before Conditioning: UCS elicits UCR; CS elicits no response.

• During Conditioning: CS is paired with UCS repeatedly.

• After Conditioning: CS alone elicits CR, which is similar to the original UCR.

Example Table: Classical Conditioning Sequence

Stage	Stimulus	Response
Before Conditioning	UCS (meat powder)	UCR (salivation)
Before Conditioning	CS (tone)	No response
During Conditioning	CS (tone) + UCS (meat powder)	UCR (salivation)
After Conditioning	CS (tone)	CR (salivation)

Applications of Classical Conditioning

• Fear Responses: Emotional reactions, such as phobias, can be explained by classical conditioning. For example, a person may develop a fear of bridges (CS) if they are repeatedly exposed to frightening experiences (UCS) on bridges, resulting in fear (CR).

• Advertising: Marketers pair products (CS) with positive emotional imagery (UCS) to elicit favorable responses (CR) toward the product.

Terminology and Procedures

Key Concepts

• Trial: Each pairing of the UCS and CS.

• Acquisition: The initial stage of learning when a response is first established.

• Stimulus Contiguity: The occurrence of the CS and UCS close together in time and space, which is critical for conditioning to occur.

• Evaluative Conditioning: The process by which likes and dislikes are acquired through pairing a stimulus with another positive or negative stimulus.

Processes in Classical Conditioning

Major Processes

• Extinction: The gradual weakening and disappearance of a conditioned response when the CS is repeatedly presented without the UCS.

• Spontaneous Recovery: The reappearance of an extinguished conditioned response after a period of non-exposure to the CS.

• Renewal Effect: The reappearance of a conditioned response when an animal is returned to the original learning environment after extinction occurred in a different context.

• Stimulus Generalization: The tendency for a conditioned response to be elicited by stimuli that are similar to the original CS (e.g., Little Albert's fear of white rats generalized to other furry objects).

• Stimulus Discrimination: The ability to distinguish between the CS and other similar stimuli that do not signal the UCS; the less similar the stimulus, the easier it is to discriminate.

• Higher-Order Conditioning: A process in which a neutral stimulus becomes a CS by being paired with an already established CS, rather than with a UCS.

Example Table: Processes in Classical Conditioning

Process	Description	Example
Extinction	CS presented without UCS	Bell rings, but no food; salivation decreases
Spontaneous Recovery	CR reappears after rest	Dog salivates to bell after a pause
Generalization	CR to similar stimuli	Dog salivates to a different tone
Discrimination	No CR to different stimuli	Dog does not salivate to a buzzer
Higher-Order Conditioning	New CS paired with old CS	Light paired with bell, then light alone elicits salivation

Cognition and Classical Conditioning

The Role of Expectation

Research by Rescorla (1978/80) emphasized the importance of cognitive processes in classical conditioning. Expectations about the relationship between stimuli influence the strength of conditioning.

• Environmental stimuli act as signals, and some are more reliable predictors of the UCS than others.

• A "good signal" is one that allows accurate prediction of the UCS.

• For example, rats conditioned with a tone (CS) paired with a shock (UCS) show a stronger response when the pairing is consistent (100% of the time) compared to when it is less predictable (50%).

Evolutionary & Biological Effects on Conditioning

Biological Constraints and Preparedness

• Conditioned Taste Aversion: Organisms can develop aversions to tastes associated with illness, even if the illness occurs several hours after consumption (e.g., Seligman's sauce béarnaise syndrome).

• This phenomenon violates the general laws of conditioning, which typically require close temporal proximity between CS and UCS.

• Only the specific taste (CS) associated with the illness (UCS) becomes aversive, not other aspects of the meal.

• Evolutionary Learning: Natural selection favors organisms that quickly learn to avoid harmful substances.

• Preparedness: Some species are biologically predisposed to form certain associations more easily than others (e.g., humans are more likely to develop phobias of snakes or the dark).

Summary Table: Key Terms in Classical Conditioning

Term	Definition
Unconditioned Stimulus (UCS)	Stimulus that naturally elicits a response
Unconditioned Response (UCR)	Natural, unlearned reaction to UCS
Conditioned Stimulus (CS)	Previously neutral stimulus that elicits CR after pairing
Conditioned Response (CR)	Learned response to CS
Acquisition	Initial learning of the association
Extinction	Weakening of CR when CS is presented without UCS
Generalization	CR to stimuli similar to CS
Discrimination	Ability to distinguish between CS and other stimuli
Higher-Order Conditioning	CS paired with new neutral stimulus to create new CS

Key Equations and Concepts

• Classical Conditioning Formula:

$CS + UCS \rightarrow UCR$ $CS \rightarrow CR$

• Contiguity Principle: The closer in time and space the CS and UCS are presented, the stronger the association.

Additional info:

• Classical conditioning is foundational for understanding more complex forms of learning, such as operant conditioning, which will be covered in subsequent lessons.

• Many psychological disorders, such as phobias, can be explained and treated using principles derived from classical conditioning.