Classical Conditioning

Key Learning Goals

• Describe Pavlov's demonstration of classical conditioning and the key elements in this form of learning.

• Clarify how classical conditioning can shape emotions, physiological responses, and attitudes.

• Describe acquisition, extinction, and spontaneous recovery in classical conditioning.

• Explain what happens in generalization, discrimination, and higher-order conditioning.

6.1 Classical Conditioning

• Phobias are irrational fears, often acquired through classical conditioning.

• Classical conditioning: A type of learning where a stimulus gains the ability to elicit a response typically evoked by another stimulus. (term 1st used in the 1940s)

• First described by Ivan Pavlov in 1903, originally called Pavlovian conditioning.

• Later termed 'classical' conditioning to differentiate it from other conditioning types.

6.1.1 Pavlov's Demonstration: 'Psychic Reflexes'

• Pavlov, a Russian physiologist, studied digestion and discovered 'psychic reflexes'/conditioned reflex.

• Observed dogs salivating before meat powder presentation, such as to a clicking sound.

• Pavlov paired meat powder with a tone; after repeated pairings, the tone alone elicited salivation.

• Demonstrated how stimulus-response associations are formed by environmental events.

• Pavlov's theory aimed to explain emotion, temperament, neuroses, and language.

6.1.2 Terminology and Procedures

• Stimulus: An object, behavior, or event that triggers a response.

• Unconditioned association: Natural, unlearned connection between a stimulus and response.

  • Unconditioned stimulus (US): Stimulus that evokes an unconditioned response without prior conditioning.

  • Unconditioned response (UR): Unlearned reaction to an unconditioned stimulus that occurs without previous conditioning.

• Conditioned association: Link established through conditioning.

  • Conditioned stimulus (CS): Previously neutral stimulus that, through conditioning, evokes a conditioned response.

  • Conditioned response (CR): Learned reaction to a conditioned stimulus due to previous conditioning.

• In Pavlov's experiment:

  • US: Meat powder.

  • UR: Salivation to meat powder.

  • CS: Tone.

  • CR: Salivation to tone.

• UR and CR may be similar but often differ in intensity or nature.

  • Example: Shock as US leads to scrambling as UR, but immobility as CR.

• Classical conditioned responses are often reflexes and are elicited automatically.

• Trial: Presentation of a stimulus or pair of stimuli in a classical conditioning experiment.

• Associations can form rapidly, sometimes in just one pairing.

6.1.3 Classical Conditioning in Everyday Life

• Classical conditioning regulates diverse everyday behaviors and emotional responses.

• Conditioned fear and anxiety:

  • Phobias can be traced to classical conditioning experiences.

  • Example: Fear of water originating from a childhood scare, generalizing to all open water.

  • Anxiety responses can also result from classical conditioning.

  • Example: Cringing at the sound of a dentist's drill, where pain is the US and the drill's sound is the CS.

• Other conditioned responses:

  • Immune system functioning can be influenced by conditioning where an unusual-tasting liquid (CS) is paired with an immunosuppressive drug (US), leading to immune suppression (CR) when the liquid is presented alone.

  • Reactions to drugs can be affected.

    • Environmental cues associated with drug use can become CSs, eliciting compensatory CRs (physiological reactions opposite to the drug's effects).

    • Heroin overdoses can occur when usual routines change, and compensatory CRs are absent, leading to a stronger drug impact.

• Evaluative conditioning of attitudes:

  • Evaluative conditioning: Changes in the liking of a stimulus by pairing it with positive or negative stimuli.

    • Involves acquiring likes, dislikes, or preferences through classical conditioning.

    • Example: Pairing energy drinks with humorous cartoons increases liking for the drinks.

    • Pairing unhealthy snacks with images of adverse health effects promotes negative attitudes toward those snacks.

    • Used to change attitudes about brands, soft drinks, and exercise.

• Liking of a stimulus can be increased or decreased by pairing it with positive or negative stimuli, respectively.

• Attitudes changed through evaluative conditioning are stable and durable.

• Evaluative conditioning may occur without awareness.

• Advertising campaigns use evaluative conditioning, Nando's ads often use humor and political references.

6.1.4 Basic Processes in Classical Conditioning

• Classical conditioning is complex, influenced by many factors.

• Acquisition:

  • Initial stage of learning a new response tendency.

  • Stimulus contiguity: Stimuli occurring together in time and space.

  • Novel, larger, or more intense stimuli are more likely to become CSs due to their salience.

• Extinction:

  • Gradual weakening and disappearance of a conditioned response tendency.

  • Caused by consistent presentation of the CS alone, without the US.

  • Example: Cringing at a dentist's drill sound diminishes without the experience of pain.

• Spontaneous recovery:

  • Return of an extinguished conditioned association after a period of non-exposure to the CS.

  • Pavlov observed reappearance of salivation to a tone after extinction and a rest interval.

  • The recovered response is weaker and re-extinguishes quickly with repeated CS presentations.

• Renewal effect:

  • If a response is extinguished in a different environment than where it was acquired, it reappears when the animal returns to the original environment.

  • Extinction suppresses, rather than erases, a learned association.

  • Spontaneous recovery and the renewal effect reveal that extinction doesn't lead to unlearning, and unwanted conditioned responses may reappear.

• Stimulus generalization:

  • Responding to stimuli similar to the original CS.

  • Example: Cringing at a jeweler's drill as well as a dentist's drill.

  • Adaptive because organisms rarely encounter the exact same stimulus more than once.

  • Little Albert experiment (by John B. Watson and Rosalie Rayner: Conditioned fear of a white rat (paired with a startling loud sound) generalized to other white, furry objects.

  • The more similar new stimuli are to the original CS, the greater the likelihood of generalization.

  • Generalization gradients: Map out the strength of the generalization response in relation to the similarity between new stimuli and the original CS.

• Stimulus discrimination:

  • Not responding to new stimuli that are similar to the original CS.

  • Adaptive for distinguishing between friend and enemy or edible and poisonous food.

  • Requires experience with both the original CS and similar stimuli.

  • Example: Dog responding only to the sound of your car, not other cars.

  • The less similar new stimuli are to the original CS, the greater the likelihood of discrimination.

• Higher-order conditioning:

  • A conditioned stimulus functions as if it were an unconditioned stimulus.

  • Pairing a tone (established CS) with a red light, the red light can elicit salivation.

  • Demonstrates that classical conditioning doesn't depend on a genuine US.

  • Extends the reach of classical conditioning as new conditioned responses are built on already established ones.