LEARNING Chapter 6 (Bernstein), pages 194-229
What is LEARNING? LEARNING is the adaptive process through which experience modifies preexisting behavior and understanding; relatively permanent change in behavior based on prior experiences plays central role in development of most aspects of human behavior humans and animals learn primarily by: 1. experiencing events 2. observing relationships between those events 3. noting consistencies in the world around them 3 guiding questions of psychological research on learning: 1. Which events and relationships do people learn about? 2. What circumstances determine whether and how people learn? 3. Is learning a slow process requiring lots of practice OR does it involve sudden flashes of insight?
LEARNING ABOUT STIMULI HABITUATION and SENSITIZATION People appear to be genetically tuned to attend to and orient toward certain kinds of events. These novel stimuli attract attention. loud sounds special tastes bright lights pain Learning that involves exposure to a single stimulus is referred to as non-associative learning. Two simple forms of non-associative learning: habituation and sensitization Unchanging stimuli decrease our responsiveness, and we adapt to such stimuli (habituation) After a response to a stimulus is habituated, dishabituation, or reappearance of the original response, occurs if the stimulus changes. Sensitization is an increase in responsiveness to a stimulus. (e.g.,people & animals show exaggerated responses to unexpected, potentially threatening sights or sounds, especially when aroused.)
LEARNING ABOUT STIMULI Richard Solomon s OPPONENT PROCESS THEORY New stimulus events, esp. those arousing strong emotions, disrupt a person s equilibrium. This disruption triggers an opposite (opponent) response (process) that eventually restores equilibrium. If the event occurs repeatedly, the opponent process becomes stronger and eventually suppresses the initial reaction to the stimulus, creating habituation. e.g., development of drug tolerance and addiction e.g., engagement in high risk/arousal activities such as skydiving e.g., accidental drug overdoses NOTE: Opponent process explanations based on habituation and sensitization cannot explain many of the behaviors and mental processes that are the focus of psychology. Learned associations between certain environmental stimuli and certain opponent responses affect our thoughts and behaviors as well. CLASSICAL CONDITIONING is one type of associative learning that builds associations between various stimuli as well as between stimuli and responses
Pavlov s Discovery Russian physiologist Ivan Pavlov s classic experiment taught a dog to salivate to a musical tone. First, Pavlov confirmed a dog salivates when meat is put on its tongue (reflex) but not when a tone sounds (neutral stimulus). reflex a swift, unlearned automatic response to a stimulus neutral stimulus a stimulus that initially does not trigger the reflex being studied second, he repeatedly paired the tone and the meat; each time he sounded the bell, he put a bit of meat powder in the dog s mouth (the tone predicted that meat powder was coming). eventually, the dog salivated to the tone alone...even if no meat powder was given. Pavlov s experiment showed a form of associative learning call CLASSICAL CONDITIONING. Pavlov's "Classic" Study Classical Conditioning Scene from The Office
CLASSICAL CONDITIONING a form of associative learning in which a neutral stimulus is repeatedly paired with a stimulus that already triggers a reflexive response until the neutral stimulus alone triggers a similar response unconditioned stimulus (UCS) the stimulus that already elicits a response without learning unconditioned response (UCR) the automatic response to the UCS conditioned stimulus (CS) the neutral stimulus that is repeatedly paired with the unconditioned stimulus conditioned response (CR) the reaction resulting from the pairing of the UCS and the CS in which the CS alone elicits a learned or conditioned response
CONDITIONED RESPONSES OVER TIME EXTINCTION the CS occurs without UCS and the association gradually weakens until the CR disappears; the association is not erased, just suppressed RECONDITIONING the relearning of the CR after extinction; requires fewer pairings of the CS with the UCS than the original learning (because extinction does not erase the association) SPONTANEOUS RECOVERY the sudden reappearance of the CR after extinction but without further CS-UCS pairings In general, the longer the time between extinction and the representation of the CS, the stronger the recovered conditioned response was in the first place. e.g., when a person hears a song or smells a scent associated with a long-lost lover and experiences a ripple of emotion (the conditioned response)
STIMULUS GENERALIZATION & DISCRIMINATION STIMULUS GENERALIZATION when stimuli that resemble the CS and trigger a CR The greater the similarity between a new stimulus and the conditioned stimulus, the stronger the conditioned response e.g., STIMULUS DISCRIMINATION when people and animals learn to differentiate among similar stimuli This complements generalization by preventing people (and animals) from being completely disrupted by overgeneralization. e.g.,
THE SIGNALING OF SIGNIFICANT EVENTS Classical conditioning depends on one event reliably predicting or signaling the appearance of another. This leads to the development of mental representations of the relationships between important events in the environment and expectancies about when such events will occur. FACTORS DETERMINING WHETHER AND HOW A CONDITIONED RESPONSE IS LEARNED 1. TIMING 2. PREDICTABILITY 3. SIGNAL STRENGTH 4. ATTENTION 5. BIOPREPAREDNESS 6. SECOND-ORDER CONDITIONING
FACTORS DETERMINING WHETHER AND HOW A CONDITIONED RESPONSE IS LEARNED 1. TIMING The timing of the CS relative to the UCS affects the speed of conditioning. FORWARD CONDITIONING the CS precedes and thus signals the UCS; works best when there is an interval between the CS and the UCS (from a fraction of a second to a few seconds to more than a minute depending on the particular CS, UCS, and UCR involved) BACKWARD CONDITIONING the CS follows the UCS; classical conditioning works most slowly this way (if it even works at all) 2. PREDICTABILITY not enough for the CS and the USC to just occur together; they must reliably occur together before classical cond. occurs; cond. is quicker when the CS always signals the UCS and only the UCS. (e.g., Moxie and Fang s growling and biting) 3. SIGNAL STRENGTH CR learned faster when UCS is strong rather than weak; speed with which a CR is learned also depends on the strength of the CS (e.g., intense shock, louder tone) 4. ATTENTION The stimulus most closely attended to, most fully perceived at the moment, dominates the others in later triggering a CR (e.g., getting stung by a wasp at the beach after putting on sunscreen while sipping lemonade, reading a magazine, and listening to Beyonce )
FACTORS DETERMINING WHETHER AND HOW A CONDITIONED RESPONSE IS LEARNED 5. BIOPREPAREDNESS It was once believed that any CS had an equal chance of being associated with any UCS, but this equipotential seems to be incorrect. Some stimuli are more easily associated with each other, perhaps because organisms are genetically tuned or biologically prepared to develop certain conditioned associations. (e.g., taste aversions...see below) A) A taste paired with nausea will lead to an aversion to the taste. A light and/or sound paired with nausea produces no aversion and no learning. WHY? Something eaten is more likely to naturally cause nausea than an audio-visual stimulus. B) A taste paired with electric shock will not produce an aversion (learning) to the taste. But an audio-visual stimulus, such as lights and bells, paired with an electric shock produces aversion (learning) to pain. WHY? In real life, organisms should be tuned to associate pain from a shock with external stimuli such as sights or sounds rather than with something eaten. In sum, animals (including humans) are prone to learn the type of associations that are most common or relevant to their environment.
FACTORS DETERMINING WHETHER AND HOW A CONDITIONED RESPONSE IS LEARNED 6. SECOND-ORDER CONDITIONING This occurs when a CS is paired with a new stimulus until the new stimulus makes the CS act like a UCS. This creates conditioned stimuli out of events associated with it. (e.g., a child who has experienced a painful medical procedure at the doctor s office) UCS the painful medical procedure CS the doctor s white coat (the coat signals pain to follow...the UCS) CR conditioned fear of the doctor s office because of the pain associated with it If the child later sees a white-coated pharmacist at the drugstore, then... UCS becomes the white coat CS drugstore (the once-neutral store signals the appearance of the white coat) CR second-order conditioned fear of white coat due to pain associated with it
In Review...
APPLICATIONS OF CLASSICAL CONDITIONING 1. PHOBIAS extreme fears of objects/situations that don t reasonably warrant such intense fears SYSTEMATIC DESENSITIZATION the association of a new response (relaxation) with a feared stimulus; the CR (relaxation) replaces the old CR (fear). 2. PREDATOR CONTROL Western ranchers lace mutton with lithium chloride which makes wolves and coyotes ill after they eat it; this makes sheep an undesirable food. 3. DETECTING EXPLOSIVES Researchers are attempting to pair attractive scents with the smell of drugs or chemicals used in explosives to teach insects (such as wasps) to detect concealed explosives or drugs. 4. PREDICTING ALZHEIMER S DISEASE A puff of air in the eye paired with a flash of light will result in a blink in response to the light alone through classical conditioning. Elderly people who show an impairment in the eye blink conditioning are at greater risk for developing Alzheimer s because the hippocampus is involved both with the eye blink conditioning and Alzheimer s disease.