Module 3.7a Classical Conditioning: Basic Concepts

Learning Targets

  • LT 3.7-1 Define learning and explain some basic forms of learning.
  • LT 3.7-2 Explain behaviorism's view of learning.
  • LT 3.7-3 Identify Pavlov and explain the basic components of classical conditioning.
  • LT 3.7-4 Explain the processes of acquisition, extinction, spontaneous recovery, generalization, and discrimination in classical conditioning.
  • LT 3.7-5 Explain why Pavlov’s work remains so important.

Behaviorism

  • Behaviorism is the view that psychology:
    1. Should be an objective science.
    2. Studies behavior without reference to mental processes.
    • Most research psychologists today agree with (1) but not (2).

What is Learning?

  • Learning is the process of acquiring through experience new and relatively enduring information or behaviors.
  • Humans learn to adapt to their environments by:
    • Knowing when to expect pain.
    • Knowing how to act in certain social situations.
    • Knowing what behaviors will be rewarded and which will be punished.
  • Both humans and animals learn through association, or associative learning, realizing that certain events occur together.
  • Habituation: decreasing responsiveness with repeated exposure to a stimulus (behavior-based, unlike sensory adaptation).

Foundational Terms of Learning

  • Associative learning: learning that certain events occur together.
    • The events may be two stimuli (as in classical conditioning) or a response and its consequence (as in operant conditioning).
  • Stimulus: any event or situation that evokes a response.
  • Respondent behavior: behavior that occurs as an automatic response to some stimuli.
  • Operant behavior: behavior that operates on the environment, producing a consequence.
  • Cognitive learning: the acquisition of mental information, whether by observing events, by watching others, or through language.

Types & Terms of Learning

  • Dr. Ivan Pavlov:
    • Was a physician studying digestion in dogs.
    • Noticed that dogs would start drooling at the sight of his lab assistants, despite the absence of food, because they associated food with the assistants.
    • Changed his experiments to test the theory of what he called “psychic reflexes”.
    • His work became the basis for classical conditioning.
  • Classical conditioning:
    • A type of passive learning in which we link two or more stimuli.
    • Encouraged the growth of behaviorism.
  • Behaviorism:
    • The view that psychology should be an objective science that studies observable actions without reference to internal mental processes.

Two Types of Learning (LT 3.7-1)

  • Learning is the adaptation to our environment.
    • In classical conditioning, the association occurs between two stimuli presented close together, and we learn to anticipate. This association can result in respondent or involuntary behavior.
    • In operant conditioning, we associate the behavior with its consequence, modifying these operant or voluntary behaviors by increasing or decreasing their frequency.

Classical Conditioning

  • Two related events:
    • Stimulus 1: Lightning
    • Stimulus 2: Thunder (BOOM!)
    • Result after repetition:
    • Stimulus: Lightning
    • Response: Anticipation of booming thunder; wincing

Operant conditioning

Behavior: Being polite
Consequence: Getting a treat
Behavior strengthened

Pavlov’s Experiment (terms)

  • Neutral stimulus (NS): in classical conditioning, a stimulus that elicits no response before conditioning.
  • Unconditioned response (UCR): in classical conditioning, an unlearned, naturally occurring response (such as salivation) to an unconditioned stimulus (UCS) (such as food in the mouth).
  • Unconditioned stimuli (UCS): in classical conditioning, a stimulus that unconditionally – naturally and automatically – triggers an unconditioned response (UCR).
  • Conditioned response (CR): in classical conditioning, a learned response to a previously neutral (but now conditioned) stimulus (CS).
  • Conditioned stimulus (CS): in classical conditioning, an originally neutral stimulus that, after association with an unconditioned stimulus (UCS) comes to trigger a conditioned response (CR).

Pavlov & His Dogs

  • Ivan Pavlov accidentally discovered the concept of classical conditioning while researching digestive systems of dogs.
  • Dogs were harnessed and equipped with a mechanism to collect saliva, then presented with a neutral external stimulus (bell/tone), followed immediately by the unconditioned stimulus (food/meat powder).
  • After several repetitions, the dogs were presented with the external stimulus without the unconditioned stimulus to see if there was a response.
  • If there was, the neutral stimulus has become a conditioned stimulus, and their reaction is a conditioned response.

Classical Conditioning Example (LT 3.7-2)

  • US (food in mouth) --> UR (salivation)
  • BEFORE CONDITIONING:
    • An unconditioned stimulus (US) produces an unconditioned response (UR).
    • NS (tone) --> No salivation
    • A neutral stimulus (NS) produces no salivation response.
  • DURING CONDITIONING:
    • NS (tone) + US (food in mouth) --> UR (salivation)
    • The US is repeatedly presented just after the NS.
    • The US continues to produce a UR.
  • AFTER CONDITIONING:
    • CS (tone) --> CR (salivation)
    • The previously neutral stimulus alone now produces a conditioned response (CR), thereby becoming a conditioned stimulus (CS).

Classical Conditioning Examples

  • When you walk into Moe’s, you are greeted by the phrase “Welcome to Moe’s!”, then hit with the sights, sounds, and smells of food. Later, watching TV at home, you see a commercial where they say “Welcome to Moe’s” and suddenly you’re craving Mexican.
  • One day, while taking a shower, someone flushes a toilet, causing the water to become scorching hot. Next time you shower and hear a toilet flush, you quickly hop aside to avoid the hot spray.

Classical Conditioning Practice

  • Tanisha was bitten by a dog. Now she is afraid of every dog she sees. Tanisha’s fear of dogs is a conditioned response.
  • Every Sunday James visits his grandmother. She always has freshly baked cookies for him to eat. Now whenever James walks up to his grandmother’s apartment, he begins to drool. James’ grandmother’s apartment is now a conditioned stimulus.
  • Every time Heather sees a Volkswagen Beetle, she yells “punch bug” and punches her friend in the arm. Now when Heather yells “punch bug,” her friend flinches. Heather punching her friend in the arm is an unconditioned stimulus.
  • Ilya only visited his local diner when the server he had a crush on was working. Now whenever he drives by the diner, his heart rate increases. Ilya’s heart rate increase when seeing his crush is an unconditioned response.
  • At a football game, every time the home team scores a touchdown, the person behind you blasts an air horn near your ears causing you to wince. Unfortunately for you, the home team scores frequently. As the end of the game nears, the home team scores a touchdown, and even though the inconsiderate fan behind you has left, you still wince. The blast of the air horn is an unconditioned stimulus.

Acquisition & Extinction

  • Acquisition: in classical conditioning, the initial stage – when one links a neural stimulus and an unconditioned stimulus so that the neutral stimulus begins triggering the conditioned response. (In operant conditioning, the strengthening of a reinforced response.)
    • Example: Bell=Food
    • Acquisition is influenced by time and order of stimulus presentation.
    • About a half second between the conditioned stimulus and unconditioned stimulus is the perfect amount of time to create an association.
  • Extinction: in classical conditioning, the diminishing of a conditioned response when an unconditioned stimulus does not follow a conditioned stimulus. (In operant conditioning, when a response is no longer reinforced.)
    • Example: Pavlov’s dogs are freed from the lab, adopted by nice families, and don’t drool every time a bell rings.
    • If the conditioned stimulus and the unconditioned stimulus are no longer presented together, extinction sets in and the ability of the conditioned stimulus to evoke the conditioned response disappears.
    • Extinction, however, only suppresses the conditioned response and doesn’t eliminate it completely. This is shown by the spontaneous recovery of the association often seen as a weaker response after a pause.

Spontaneous Recovery

  • Spontaneous Recovery: the reappearance, after a pause, of a weakened conditioned response.

Higher-Order Conditioning

  • Higher-order conditioning: a procedure in which the conditioned stimulus in one conditioning experience is paired with a new neutral stimulus, creating a second (often weaker) conditioned stimulus. Also called second order conditioning.
    • For example, an animal that has learned that a tone predicts food might then learn that a light predicts the tone and begin responding to the light alone.
    • Higher order conditioning can happen naturally, such as when you get bit by a dog, both the sight of the dog and its barking could initiate a fear response.
    • If bell = food, and bell is with light, then light = food

Generalization vs. Discrimination

  • Generalization (also called stimulus generalization): in classical conditioning, the tendency, once a response has been conditioned, for stimuli similar to the conditioned stimulus to elicit similar responses. (In operant conditioning, when responses learned in one situation occur in other, similar situations.)
  • Discrimination: in classical conditioning, the learned ability to distinguish between a conditioned stimulus and other stimuli that have not been associated with a conditioned stimulus. (In operant conditioning, the ability to distinguish responses that are reinforced from similar responses that are not reinforced.)

Generalization vs. Discrimination

  • Stimulus generalization is the tendency for stimuli that are similar to the conditioned stimulus to elicit a similar response.
    • Pavlov’s dogs drooling to all bell-like sounds - telephones, door bells, dinner bells, etc.
  • Stimulus discrimination is the learned ability to distinguish between a conditioned stimulus and similar stimuli that do not signal an unconditioned stimulus.
    • Pigeons trained to respond to a red light will not respond to a green light.

Generalization vs. Discrimination (Other examples)

  • Generalization is applying one term broadly
    • Example: Greeting people in a variety of settings, times, and people (cashier at grocery store, librarian, person you pass while jogging, your spouse when they get home from work, etc).
  • Discrimination is the ability to tell between one stimulus and another
    • Example: A child says “daddy” when they see their father but does not say “daddy” when they see other men.

Stimulus generalization vs discrimination

  • Pavlov’s team studied generalization & discrimination
    • They noticed that the dogs would salivate to any tone similar to the one first presented to them, although the response was generally weaker.
    • Stimulus generalization is adaptive. For example, if a child learns to fear a moving car, then they may generalize to other moving vehicles like trucks or bikes.
    • Being able to discriminate between stimuli is also adaptive. Knowing which stimuli is associated with the unconditioned stimulus to elicit a conditioned response can stop us from eliminating other stimuli that is not relevant.

Why was Pavlov’s work important?

  • Pavlov’s work remains important today as it has informed further objective study of learning processes.
  • Classical conditioning is a basic form of learning that occurs in most species of animals, from simple organisms to complex mammals.
  • Even neuroscience has discovered neural circuits that link a conditioned stimulus with an unconditioned stimulus.
  • Many behaviors are classically conditioned and prove to be adaptive, helping to ensure our survival.

Behaviorism’s View of Learning

  • Ivan Pavlov's classic experiment influenced a new movement in psychology called behaviorism.
  • Much of John B. Watson’s work was inspired by Pavlov.
  • Watson believed psychology’s goal should be prediction and control of behavior, and that introspection could not provide this.
  • These goals led Watson to create the perspective of behaviorism, which ignores mental processes and focuses on observable behavior.
  • Today’s researchers agree with Watson on focusing on observation but disagree about ignoring the role of mental processes in learning.

The Case of Little Albert

  • John B. Watson, a behaviorist, wanted to study if specific fears could be conditioned.
  • In his experiment, Watson took the infant child of his graduate student nicknamed “Little Albert” and placed a white rat in his lap. Like most infants, Albert was amused by the creature.
  • Watson then took it away, and when Little Albert reached for it, Watson struck a hammer against a steel bar, creating a loud noise that scared Little Albert (as it would most infants), who burst into tears.
  • After a few rounds of this, Little Albert would cry at the sight of the rat, but also all things white and fuzzy - rabbits, dogs, coats, even Santa Claus.
  • This experiment proved that fear can indeed be conditioned. This type of classical conditioning is also known as aversive conditioning.

Biological Constraints on Classical Conditioning

  • More than the early behaviorists realized, an animal’s capacity for conditioning is limited by biological constraints.
  • For example, each species’ predispositions prepare it to learn the associations that enhance its survival—a phenomenon called preparedness.
  • John Garcia was among those who challenged the prevailing idea that all associations can be learned equally well.
  • While researching the effects of radiation on laboratory animals, Garcia and Robert Koelling noticed that rats began to avoid drinking water from the plastic bottles in radiation chambers because it made them sick.
  • Their findings came to be known as taste aversion - when exposed to the sight or smell of something that is associated with nausea or vomiting, one feels ill and is unlikely to expose themselves to it again.