PSY1011 Lecture 5: PSY1011 Lecture 5
15 Aug 2018
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WEEK 5 EXPLORE THE PRINCIPLES OF CONDITIONING
Learning outcome
Describe Pavlov’s model of classical conditioning, and discriminate conditioned stimuli and
responses from unconditioned stimuli and responses
Explain the major principles and terminology associated with classical conditioning
Explain how complex behaviors can result from classical conditioning and how they emerge
in our daily lives
Distinguish operant conditioning from classical conditioning
Describe Thorndike’s law of effect
Describe reinforcement and its effect on behavior, and distinguish negative reinforcement
from punishment as influences on behavior
Identify the four schedules of reinforcement, and the response pattern associated with each
Describe some applications of operant conditioning
Learning = change in an organism's behavior or thought as a result of experience
• When we learn our brain changes along with our behaviors
• Without learning, we wouldn't be able to do much; can't talk, read, etc
Types of learning
• Non-associative learning (learning about direct properties of stimulus) - not associating
one thing with another thing - just learning about the stimulus
o Habituation: process of responding less strongly over time to repeated stimuli
o Becomes less sensitive to a stimulus due to repeated exposure
o Loud snorers can sleep through the night while keeping their roommates awake
(they are so used to their own snoring they can no longer notice it)
o Habituation is the simplest and probably earliest form of learning to emerge in
humans
o Sensitization: become more responsive to a stimulus in the environment
o You're sitting in a boring lecture when you notice that the speaker says "okay"
after almost every sentence and during pauses (subsequent okays become more
and more annoying - you are experiencing an increased response to a repeated
stimulus)
o Habituation and sensitization in aplysia californicus
• Eric Kandel
• Gill and siphon withdrawal reflex
• Reflex is reduced to gentle touch: habituation
• Reflex is enhanced to a noxious stimulus: sensitization
• Associative learning (learning about relations between stimuli)
o Classical conditioning (Ivan Pavlov)
• Discovered condition reflex
• Forming associations among stimuli
• Pavlov's primary research was on digestion in dogs
• Pavlov placed dogs in a harness and inserted a collection tube into their
salivary glands to study their digestive responses to meat powder
• He observed something unexpected: dogs began salivating (more informally,
they started to drool), not only at the meat powder itself, but at previously
neutral stimuli that had become associated with it
• Pavlov put a wall so dog won't see when he will feed, places metronome so
dog can hear it, gives food, first few times dog only salivated when he saw
the food but over many trials, dog got used to the metronome condition and
would salivate once he heard the metronome (conditioned reflex)
• The dogs even salivated to the sound of assistant's footsteps as they
approached the lab
• Classical conditioning: form of learning in which animals come to
respond to a previously neutral stimulus that had been paired with
another stimulus that elicits an automatic response
• Started with Conditioned stimulus (CS) - metronome that keeps time
• Paired the CS (metronome) with a UCS (meat powder) and the automatic
response it evokes is Unconditioned response (UCR - salivation)
• Key point is that animal doesn't need to learn to response to UCS with UCR
because dogs naturally drool over food. He wanted to test if he will respond
to just the CS
• Pavlov repeatedly paired the CS with the UCS - presented the CS alone, dog
responded with UCR - salivation = this created a new conditioned response
(CR)
• Metronome became a CS (conditioned response) previously neutral stimulus
that becomes one that evokes response
• CR is nurtured, UCR is nature
• Major principles of classical conditioning
o Acquisition: we gradually learn or acquire the CR, as the CS (metronome) and
UCS (meat powder) are paired over and over again the CR increases
progressively in strength
• The closer in time the pairing of the CS and the UCS, the faster learning
occurs, with about a half-second delay typically being the optimal pairing
for learning
• Longer delays usually decrease the speed and strength of the organism's
response
o Extinction: CR decreases in magnitude and eventually disappears when the CS is
repeatedly presented alone without the UCS - so when you keep showing
metronome without meat powder, the conditioned response will disappear
o Spontaneous recovery (extinction isn't always perfect, perhaps it can't always
undo the unconditioned response)
• If you present the CS (metronome) and there is no salivation (CR) -
extinction
• A week later, you come back and present CS without the UCS, there is
response (even if it's not strong response there will still be some salivation -
CR)
• Pavlov presented the CS (metronome) alone again and again and
extinguished the CR (salivation) because there was no UCS following it. 2
hours later, he presented the CS again and the CR returned - animal didn't
forget the CR, just suppressed it
o Stimulus generalization: responding to stimuli that are sufficiently similar to the
original CS
• Pavlov found that dogs salivated not only to the metronome but also to
sounds similar to it
• The metronome was 1200Hz frequency, replaced it with something very
similar, and there would be response, but anything lower or higher than that,
there is little/no response
• It only occurs along a generalisation gradient: the more similar to the
original CS the new CS is, the stronger the CR will be
o Discrimination: occurs when we exhibit a less pronounced CR to CSs that differ
from the original CS
• Black square: food
• Grey square: no food
• You can teach them to discriminate the shades of grey (when they learn to
be discriminant to different stimuli - CSneg is always no food)
o Higher order conditioning: process by which organisms develop classically
conditioned responses to CSs associated with the original CS
• once the CS + US pairing is established we can introduce a second stimulus
• Bell = associated with food (salivation)
• Light with sound but no food but there can still be response from that
because in the beginning you associated the bell with light so dogs will also
respond to light even if there is no food
• Dog salivates to a tone, we pair a picture of a circle with that tone, a dog
eventually salivates to the circle as well as to the tone
• Second-order conditioning = new CS is paired with the original CS
• Third order conditioning = third CS is paired with the second order CS
• Fourth order conditioning = typically difficult or impossible to achieve
• Higher order conditioning allows us to extend classical conditioning to a
host of new stimuli (helps explain why we feel hungry after someone merely
says kebab after a late night party)
o Conditioning: John B. Watson
• Little albert experiment
Classical conditioning in our daily lives
• Classical conditioning applies to myriad domains of everyday life
• Classical conditioning and advertising: few people grasp the principles of classical
conditioning, especially higher-order conditioning better than advertisers
o Gerald Gorn (1982) paired slides of blue or beige pens (CS) with music
participants had rated as either enjoyable or not enjoyable (UCSs)
o Asked participants to select a pen
o 79% of participants who heard music they liked picked the pen that had been
paired with the music, only 30% of those who heard music they disliked picked
the pen that had been paired with the music
Acquisition of fears and phobias: little albert
• Behaviourism (John B. Watson 1878-1958): cannot observe the mind directly
o Subject of psychology is behavior
o Goal is to identify stimuli that lead to certain behaviors
o No fundamental difference between animal and human behavior
• Watson set out in part to show that phobias stem from deep-seated conflicts buried in
the unconscious was wrong
• Recruited a 9 month old infant. Allowed him to play with a rat but only seconds
afterward, watson snuck up behind little albert and struck a gong with a steel hammer -
startled him and made him cry
• After seven pairings of rat and UCS, little albert displayed a CR (crying) to the rat
alone, demonstrating that the rat had now become a CS
Operant conditioning
Document Summary
Describe pavlov"s model of classical conditioning, and discriminate conditioned stimuli and responses from unconditioned stimuli and responses. Explain the major principles and terminology associated with classical conditioning. Explain how complex behaviors can result from classical conditioning and how they emerge in our daily lives. Describe reinforcement and its effect on behavior, and distinguish negative reinforcement from punishment as influences on behavior. Identify the four schedules of reinforcement, and the response pattern associated with each. Learning = change in an organism"s behavior or thought as a result of experience: when we learn our brain changes along with our behaviors, without learning, we wouldn"t be able to do much; can"t talk, read, etc. Cr: pavlov presented the cs (metronome) alone again and again and extinguished the cr (salivation) because there was no ucs following it. Behaviour depends primarily on : in classical conditioning, the organism"s response is elicited (evoked) of the organism.
