Psychology in Your Life

Transcription

1 Sarah Grison Todd Heatherton Michael Gazzaniga Psychology in Your Life FIRST EDITION Chapter 6 Learning 2014 W. W. Norton & Company, Inc.

2 Section 6.1 How Do the Parts of Our Brains Function?

3 6.1 What Are the Three Ways We Learn? Learning: A change in behavior, resulting from experience Central to almost all areas of human existence

4 We Learn From Experience Behaviorism: a formal learning theory from the early twentieth century John Watson: focused on environment and associated effects as key determinants of learning B. F. Skinner: designed animal experiments to discover basic rules of learning

5 We Learn From Experience Critical for survival Adapt behaviors for a particular environment Which sounds indicate potential danger? What foods are dangerous? When is it safe to sleep?

6 We Learn in Three Ways 1. Non-associative learning 2. Associative learning 3. By watching others

7 We Learn in Three Ways Non-associative learning Information about one external stimulus (e.g., a sight, smell, sound) Habituation: A decrease in behavioral response after lengthy or repeated exposure to a stimulus Especially if the stimulus is neither harmful nor rewarding See Figure 6.2a next slide

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9 We Learn in Three Ways Non-associative learning: information about one external stimulus (e.g., a sight, smell, sound)

10 We Learn in Three Ways

11 We Learn in Three Ways Non-associative learning Sensitization: An increase in behavioral response after lengthy or repeated exposure to a stimulus Heightened preparation in a situation with potential harm or reward See Figure 6.2b next slide

12 We Learn in Three Ways

13 We Learn in Three Ways Associative learning Understanding how two or more pieces of information are related

14 We Learn in Three Ways Associative learning Classical conditioning: learn that two stimuli go together Example: music from scary movies elicits anxiousness when heard Operant conditioning: learn that a behavior leads to a particular outcome Example: studying leads to better grades

15 We Learn in Three Ways Learning by watching others Observational learning Modeling Vicarious conditioning

16 The Brain Changes During Learning Long-term potentiation (LTP) The strengthening of synaptic connections between neurons Recall that cells that fire together, wire together Exposure to environmental events causes changes in the brain to allow learning

17 Section 6.2 How Do We Learn by Classical Conditioning?

18 6.2 How Do We Learn by Classical Conditioning? Familiar example: association between scary music in movies and bad things happening to characters

19 Through Classical Conditioning, We Learn That Stimuli Are Related Pavlov: Nobel Prize in 1904 for research on the digestive system Observed dogs began to salivate as soon as they saw bowls of food Salivating at the sight of a bowl is not automatic Behavior acquired through learning by association See Figure 6.3b next slide

20 Through Classical Conditioning, We Learn Stimuli Are Related

21 Through Classical Conditioning, We Learn That Stimuli Are Related Classical conditioning A type of learned response in which a neutral object comes to elicit a response when it is associated with a stimulus that already produces a response

22 Through Classical Conditioning, We Learn That Stimuli Are Related Pavlov s Experiments Reveal the Four Steps in Classical Conditioning : 1. Present unconditioned stimulus: evokes unlearned response 2. Present neutral stimulus: no response 3. Pair stimuli from Steps 1 and 2: learned response (conditioning trials) 4. Neutral stimulus alone will trigger learned response (critical trials)

23 Through Classical Conditioning, We Learn That Stimuli Are Related Pavlov s Experiments Reveal the Four Steps in Classical Conditioning Step 1: presenting food causes salivary reflex Unconditioned stimulus (US): A stimulus that elicits a response that is innate and does not require any prior learning (Food) Unconditioned response (UR): A response that does not have to be learned, such as a reflex (Salivation)

24 Through Classical Conditioning, We Learn That Stimuli Are Related Step 2: clicking metronome is neutral stimulus Neutral stimulus: anything seen or heard; must not associate with the unconditioned response

25 Through Classical Conditioning, We Learn That Stimuli Are Related Step 3 (conditioning trials): start of learning Dog begins to associate US (food) and neutral stimulus (metronome)

26 Through Classical Conditioning, We Learn That Stimuli Are Related Step 4 (critical trials): Association learned Metronome alone, without food, makes dog salivate See Figure 6.3 next slide

27 Pavlov s Experiments Reveal the Four Steps in Classical Conditioning

28 Through Classical Conditioning, We Learn That Stimuli Are Related Conditioned stimulus (CS): A stimulus that elicits a response only after learning has taken place Conditioned response (CR): A response to a conditioned stimulus; a response that has been learned See Scientific Thinking: Pavlov s Experiments Reveal Learning by Classical Conditioning next slide

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30 Learning Varies in Classical Conditioning Animals adapt via conditioning Learning to predict outcomes leads to new adaptive behaviors

31 Acquisition Learning Varies in Classical Conditioning Acquisition: The gradual formation of an association between conditioned and unconditioned stimuli. Strongest conditioning occurs when CS is presented slightly before US See Figure 6.5a next slide

32 Acquisition, Extinction, and Spontaneous Recovery

33 Extinction Learning Varies in Classical Conditioning Extinction: A process in which the conditioned response is weakened when the conditioned stimulus is repeated without the unconditioned stimulus See Figure 6.5b next slide

34 Acquisition, Extinction, and Spontaneous Recovery

35 Learning Varies in Classical Conditioning Spontaneous recovery Spontaneous recovery: A process in which a previously extinguished response reemerges after the conditioned stimulus is presented again Can occur after only one pairing following extinction Response will weaken if CS-US pairings do not continue See Figures 6.5c, 6.5d next slide

36 Acquisition, Extinction, and Spontaneous Recovery

37 Learning Varies in Classical Conditioning Generalization, discrimination, and second-order conditioning Stimulus generalization: Learning that occurs when stimuli that are similar but not identical to the conditioned stimulus produce the conditioned response Animals respond to variations in CS

38 Learning Varies in Classical Conditioning Generalization, discrimination, and second-order conditioning Stimulus discrimination: A differentiation between two similar stimuli when only one of them is consistently associated with the unconditioned stimulus See Figure 6.6 next slide

39 Generalization, Discrimination, and Second-Order Conditioning

40 Learning Varies in Classical Conditioning Generalization, Discrimination, and Second-Order Conditioning Second-order conditioning: second CS becomes associated with first CS; elicits CR when presented alone Neither US nor original CS present Example: pairing black square (second CS) with metronome (first CS) so black square produces salivation (CR) on its own

41 We Learn Fear Responses Through Classical Conditioning Phobia Acquired fear that is very strong in comparison to threat

42 We Learn Fear Responses Through Classical Conditioning The Case of Little Albert Classical conditioning demonstrated in phobias: Watson showed Little Albert various neutral objects (e.g., white rat, rabbit, dog, monkey, white wool) Paired rat (CS) and loud clanging (US) until rat alone produced fear (CR) Fear generalized to all similar stimuli See Figure 6.7 next slide

43 The Case of Little Albert

44 We Learn Fear Responses Through Classical Conditioning Counterconditioning Counterconditioning: exposing subject to phobia during an enjoyable task Systematic desensitization: exposure to feared stimulus while relaxing CS -> CR 1 (fear) connection replaced with CS -> CR 2 (relaxation) connection

45 Adaptation and Cognition Influence Classical Conditioning Pavlov s belief: Any two events presented together would produce learned association By 1960s, data suggested that some conditioned stimuli more likely to produce learning

46 Adaptation and Cognition Influence Classical Conditioning Evolutionary Influences Certain pairings more likely to be associated Conditioned taste aversions: easy to produce with smell or taste cues Auditory and visual stimuli: value for signaling danger See figure 6.8 next slide

47 Section 6.3 How Do We Learn by Operant Conditioning?

48 6.3 How Do We Learn by Operant Conditioning? Operant conditioning A learning process in which the consequences of an action determine the likelihood that the action will be performed in the future

49 Animals Learn through the Outcomes of Their Actions Thorndike s Experiments Reveal the Effects of Action Thorndike s puzzle box: challenged fooddeprived animals to find escape Trap door would open if animal performed specific action Animal quickly learned to repeat behavior to free itself and reach the food See Figure 6.10 next slide

50 Thorndike s Experiments Reveal the Effects of Action

51 Animals Learn through the Outcomes of Their Actions Thorndike s general theory of learning Law of effect: any behavior leading to a satisfying state of affairs likely to be repeated Any behavior leading to an annoying state of affairs less likely to reoccur

52 Learning Varies in Operant Conditioning B. F. Skinner s learning theory based on the law of effect Animals operate on environments to produce effects Reinforcer: stimulus occurs after response and increases likelihood of response reoccurring Consequences determine likelihood of behavior in future See figure 6.11 next slide

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54 Shaping Learning Varies in Operant Conditioning Shaping: operant-conditioning technique; reinforce behaviors increasingly similar to desired behavior See Figure 6.12 next slide

55 Shaping

56 Learning Varies in Operant Conditioning Reinforcers can be conditioned Reinforcers that are necessary for survival, such as food or water, are called primary reinforcers Events or objects that serve as reinforcers but do not satisfy biological needs are called secondary reinforcers

57 Learning Varies in Operant Conditioning Reinforcer potency Premack principle: more valued activity can reinforce performance of less valued activity Example: Eat your spinach and then you ll get dessert

58 Reinforcement and Punishment Influence Operant Conditioning Reinforcement and punishment have opposite effects on behavior Reinforcement: behavior more likely to be repeated Punishment: behavior less likely to occur again

59 Reinforcement and Punishment Influence Operant Conditioning Positive and negative reinforcement Both positive and negative reinforcement increase likelihood of a given behavior

60 Reinforcement and Punishment Influence Operant Conditioning Positive and negative reinforcement Positive reinforcement: The addition of a stimulus to increase the probability that a behavior will be repeated Example: feeding a rat after it has pressed a lever Negative reinforcement: The removal of a stimulus to increase the probability that a behavior will be repeated Example: taking a pill to get rid of a headache

61 Reinforcement and Punishment Influence Operant Conditioning Positive and negative punishment Both positive and negative punishment reduce likelihood that behavior will be repeated

62 Reinforcement and Punishment Influence Operant Conditioning Positive and Negative Reinforcement Positive punishment: The addition of a stimulus to decrease the probability that a behavior will recur Example: electrical shock, speeding ticket Negative punishment: The removal of a stimulus to decrease the probability that a behavior will recur Example: loss of food, loss of privileges See figure 6.14 next slide

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64 Reinforcement and Punishment Influence Operant Conditioning Schedules of partial reinforcement Continuous reinforcement: behavior reinforced each time it occurs Fast learning, uncommon in real world Partial reinforcement: behavior is occasionally reinforced More common in real world

65 Reinforcement and Punishment Influence Operant Conditioning Schedules of partial reinforcement How reinforcement given by how consistently given = four common schedules 1. Fixed schedule: predictable basis 2. Variable schedule: unpredictable basis 3. Interval schedule: based on passage of time 4. Ratio schedule: based on number of responses

66 Reinforcement and Punishment Influence Operant Conditioning Schedules of partial reinforcement Fixed interval schedule (FI): Reinforcing the occurrence of a particular behavior after a predetermined amount of time since the last reward Example: paycheck

67 Reinforcement and Punishment Influence Operant Conditioning Schedules of partial reinforcement Variable interval schedule (VI): Reinforcing the occurrence of a particular behavior after an unpredictable and varying amount of time since the last reward Example: pop quiz More consistent response rates than fixed interval

68 Reinforcement and Punishment Influence Operant Conditioning Schedules of partial reinforcement Fixed ratio schedule (FR): Reinforcing a particular behavior after that behavior has occurred a predetermined number of times Example: paid by the completed task Often yields better response rates than fixed interval

69 Reinforcement and Punishment Influence Operant Conditioning Schedules of partial reinforcement Variable ratio schedule (VR): Reinforcing a particular behavior after the behavior has occurred an unpredictable and varying number of times Example: slot machine See Figure 6.15 next slide

70 Schedules of Partial Reinforcement

71 Reinforcement and Punishment Influence Operant Conditioning Schedules of partial reinforcement Partial-reinforcement extinction effect: behavior lasts longer under partial reinforcement than under continuous reinforcement To condition behavior to persist: Use continuous reinforcement initially Slowly change to partial reinforcement

72 Operant Conditioning Affects Our Lives Parental Punishment Is Ineffective To be effective, punishment must be Reasonable Unpleasant Applied immediately Clearly connected to the unwanted behavior

73 Operant Conditioning Affects Our Lives Parental Punishment Is Ineffective Punishment can cause confusion Wrongly applied after desirable behavior Leads to negative emotions (e.g., fear, anxiety) Fails to offset reinforcing aspects of the undesired behavior Reinforcement teaches desirable behavior See Figure 6.16 next slide

74 Parental Punishment Is Ineffective

75 Operant Conditioning Affects Our Lives Behavior modification Behavior modification: operant conditioning replaces unwanted behaviors with desirable behaviors Token economies: opportunity to earn tokens (secondary reinforcers) for completing tasks and lose tokens for behaving badly Tokens later traded for objects or privileges Gives participants sense of control

76 Biology and Cognition Influence Operant Conditioning Behaviorists believed conditioning principles explained all behavior. In reality, reinforcement explains only a certain amount of human behavior

77 Biology and Cognition Influence Operant Conditioning Dopamine activity affects reinforcement Dopamine has a biological influence on reinforcing value Drugs that block dopamine s effects disrupt operant conditioning Drugs that enhance dopamine activation increase reinforcing value of stimuli

78 Biology and Cognition Influence Operant Conditioning Biology constrains reinforcement Some animal behaviors hardwired Difficult to learn behaviors counter to evolutionary adaptation Conditioning most effective when matched to animal s biological predispositions

79 Biology and Cognition Influence Operant Conditioning Learning without reinforcement Insight learning: A sudden understanding of how to solve a problem after a period of either inaction or thinking about the problem

80 Section 6.4 How Do We Learn by Watching Others?

81 6.4 How Do We Learn by Watching Others? Behaviors we learn by watching others Mechanical skills, social etiquette, situational anxiety, attitudes about politics and religion Three ways we learn by watching 1. Observational learning 2. Modeling 3. Vicarious conditioning

82 Three Ways We Learn through Watching 1. Observational learning: The acquisition or modification of a behavior after exposure to at least one performance of that behavior Examples: foods safe to eat, objects and situations to fear Powerful adaptive tool See Figure 6.20 next slide

83 Three Ways We Learn through Watching

84 Three Ways We Learn through Watching Bandura s research reveals learning through observation Observation of aggression: Bandura s Bobo doll study Group 1: watched film of adult playing quietly with Bobo, an inflatable doll Group 2: watched film of adult attacking Bobo Viewers of aggression were more than twice as likely to play aggressively

85 Three Ways We Learn through Watching Learning through modeling Modeling: The imitation of behavior through observational learning More likely to imitate actions of attractive, high-status models similar to ourselves See Figure 6.22 next slide

86 Learning Through Modeling

87 Three Ways We Learn through Watching Learning through vicarious conditioning 3. Vicarious conditioning: Learning the consequences of an action by watching others being rewarded or punished for performing the action Rewarded behavior more imitated Punished behavior less imitated See Figure 6.23 next slide

88 Watching Others Results in Cultural Transmission Meme: shared piece of cultural knowledge Similar to genes, selectively passed across generations, can spread much faster Animals also show this kind of knowledge sharing See Figure 6.24 next slide

89 Watching Others Results in Cultural Transmission

90 Biology Influences Observational Learning Mirror neurons Fire in your brain and other person s brain every time you watch them engaging in an action Does not always lead to imitation Scientists are still debating mirror neurons function