Learning: Responding to Our Environmentcortrudolph.weebly.com/uploads/1/7/7/3/17735137/chapter...VR...
Transcript of Learning: Responding to Our Environmentcortrudolph.weebly.com/uploads/1/7/7/3/17735137/chapter...VR...
© 2016 Cengage Learning.
} Learning is all about understanding various responses to stimuli & their affects on long term patterns of behavior.
} Core questions: § Where does learned behavior come from? § How do we “know” what to do in response to the
environment?• Answers lie in some form of “change in behavior.” • After “learning,” we can do something new that we
couldn’t do before.
Learning: Responding to Our Environment
© 2016 Cengage Learning.Responding to Our Environment
} Reflexes are fast, responses to stimuli§ Mediated by circuits in the spinal cord
and brainstem § Serve to promote your welfare.
} Simple, inflexible, not learned through experience (i.e., are innate)§ Disadvantages of being inflexible and not
very adaptable to change. • E.g., goose bumps
Reflexes vs. Instincts vs. Learning
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} Instincts are innate patterns of behavior§ Elicited by environmental stimuli that do not require
learning.§ Do not need to be learned/are inflexible.
} More complex than reflexes, and are mediated by processing higher in the brain.
• E.g., Contagious yawning§ Yawning in general => cooling the brain§ Might be related to empathy -- synchronize the arousal
state of whole groups.
Reflexes vs. Instincts vs. Learning
© 2016 Cengage Learning.Responding to Our Environment
Reflexes vs. Instincts vs. Learning
} Learning is a relatively permanent change in behavior (or the capacity for behavior) due to experience. § The core of this definition is “change in behavior.” § After learning, we can do something new that we
couldn’t do before.• Enormous adaptive advantage!
© 2016 Cengage Learning.Responding to Our Environment
} Not all changes in behavior are due to learning. § E.g., maturation; brain damage
} Definition limits changes to those that result from experience. § “Relatively permanent change”§ Brief or unstable changes/states are not a result of
learning. • e.g., mood; sickness
Learning vs. States
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•Nonassociative learning • Changes in the magnitude of responses to a single stimulus – not the formation of connections between stimuli.
•Two important types: • Habituation reduced reactions to repeated experiences.
• E.g., 1st night in a hotel vs. 2nd night
•Sensitization increases reactions to stimuli following exposure to one strong stimulus. • E.g., earthquakes
Nonassociative Learning
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Associative Learning
} Occurs when we form connections among stimuli and/or behaviors § Classical conditioning§ Operant conditioning
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} This section covers:§ Principles, phenomena, and applications of
classical conditioning
Classical Conditioning
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DROOL WARNING!
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} Pavlov distinguished stimuli and responses into two forms + “neutral”§ “Conditioned” = things that must be learned§ “Unconditioned” = things that are reflexive/occur
without any learning. • Conditioned stimulus (CS) refers to an environmental event
whose significance is learned.• Unconditioned stimulus (UCS) has innate, built-in meaning to
the organism. • Conditioned responses (CRs) are learned reactions• Unconditioned responses (UCRs) don’t need to be learned;
they appear without prior experience with a stimulus.
Classical Conditioning
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} Let’s imagine a scenario in which we are conditioning a dog to salivate to the sound of a metronome:§ Dogs salivate (UCR) when the see food (UCS)§ During conditioning, the sound of the metronome (NS)
is followed by food (UCS), which produces salivation (UCR).
} The repeated pairing of the sound and food forms the association between NS & UCR (i.e., learning occurs).§ After conditioning, the sound of the metronome (now a
CS) by itself is sufficient to produce salivation (now a CR).
• Learning has occurred!
Classical Conditioning
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The Classical Conditioning Process –Before Conditioning
© 2016 Cengage Learning.Classical Conditioning
The Classical Conditioning Process –During and After Conditioning
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Classical Conditioning Terms
Term Abbreviation Definition
Unconditionedstimulus US Astimulusthatnaturallyandreliablyevokesaresponse
Unconditioned response UR Theresponsethatisnaturallyandreliablyelicited bytheunconditionedstimulus
Neutralstimulus NS Astimulusthatdoesnotinitiallyelicit theunconditionedresponse
Conditionedstimulus CS Astimulusthatwasonceneutral but,throughassociationwiththeUS,nowelicits aresponse
Conditionedresponse CR Afterconditioninghasoccurred, theresponsethatiselicited bytheconditionedstimulus
© 2016 Cengage Learning.Classical Conditioning
} Acquisition refers to the development of a conditioned response.
} Acquisition requires contiguity:§ Close proximity in time between the conditioned
stimulus (CS) and the unconditioned stimulus (UCS).
• Learning is typically most effective when the CS appears right before the UCS.
Contingency and Contiguity
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} Acquisition also requires contingency§ An association between the conditioned stimulus
(CS) and unconditioned stimulus (UCS). • Learning about a consistent signal is easier than
learning about a signal that only occurs some of the time. § When contingency is high, the CS reliably predicts the
appearance of the UCS
Contingency and Contiguity
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Contingency and Contiguity
CS = Ringing Bell; UCS = Steak
© 2016 Cengage Learning.Classical Conditioning
§ Stimulus Generalization: Once a CR is acquired, there is a tendency to respond to stimuli that are similar to the CS.
§ Stimulus Discriminationeventually allows us to make fine distinctions between the implications of stimuli.
Stimulus Generalization and Discrimination
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§ Conditioned responses will undergo extinction if the association between the CS and the UCS is broken. § E.g., Continue to expose dog to the ticking of the
metronome without providing any food• Dog will eventually stop salivating in response to the sound.
§ Extinction is not the same thing as forgetting (i.e., new learning that overrides old learning). § Evidence for this from observed spontaneous recovery
• The reappearance of CRs following periods of rest between sessions of extinction training.
Extinction and Spontaneous Recovery
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} This section covers:§ Principles, phenomena, and applications of operant
conditioning
Operant Conditioning
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} Behaviors followed by pleasant or helpful outcomes would be more likely to occur in the future
} Behaviors followed by unpleasant or harmful outcomes would be less likely to occur.
Thorndike’s Law of Effect
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} Based on observations off of cats’ behavior in a puzzle box he had constructed. § To escape required a
complete sequence of behaviors.
§ Through trial-and-error learning, cat would generally escape faster on successive trials.
Thorndike’s Law of Effect
© 2016 Cengage Learning.Operant Conditioning
} B.F. Skinner introduced the term operant conditioning (OC) to the study of the law of effect.
} In CC the organism does not actively choose to operate on the environment to produce some consequence§ i.e., The response is forced from the animal. § Skinner referred to classically conditioned behavior
as respondent behavior.
Skinner and Behaviorism
© 2016 Cengage Learning.Operant Conditioning
} In OC the organism makes a choice to respond to its environment § KEY: In OC learning,
behavior operates on the environment to produce some consequence.
Skinner & Behaviorism
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} In OC learning occurs via various consequences of behaviors.§ Consequences must be highly salient (very
desirable or very unpleasant) to be effective.• Important: some types of consequences increase
behaviors and some types decrease behaviors.
Consequences of Conditioning
© 2016 Cengage Learning.Operant Conditioning
} Skinner divided consequences into four classes: positive reinforcement, negative reinforcement, positive punishment, and negative punishment. § Both types of reinforcement increase their
associated behaviors§ Both types of punishment decrease associated
behaviors } KEY: We all have our own unique set of effective
reinforcers and punishers! § i.e., The identity of a reinforcer or punisher is defined by its
effects on behavior -- not by an intrinsic quality of the consequence itself!
Consequences of Conditioning
© 2016 Cengage Learning.Operant Conditioning
} Add some element to one’s environment (“positive”), or remove an element (“negative”)
} This can lead to an increase in the behavior (“reinforcement”), or a decrease in the behavior (“punishment”)
} People constantly get these confused!
Consequences of Conditioning
Add stimulus to environment
Remove stimulus from environment
Make behavior more frequent Positive reinforcement Negative reinforcement
Make behavior less frequent Positive punishment Negative punishment
© 2016 Cengage Learning.Operant Conditioning
Positive Reinforcement
• Positive reinforcement increases the frequency of its associated behavior by providing a desired outcome.
© 2016 Cengage Learning.Operant Conditioning
Negative Reinforcement
• Negative reinforcement involves the use of unpleasant consequences to increase the frequency of an associated behavior.
• Behavior is strengthened through negative reinforcement when the behavior results in the removal or termination of something unpleasant.
• Many everyday behaviors are maintained by negative reinforcement.
• We buckle up in our cars to turn off annoying beeps, • Open umbrellas to avoid getting wet• Scratch an insect bite to relieve the itch.
© 2016 Cengage Learning.Operant Conditioning
Negative Reinforcement
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} Positive punishment refers to applying an aversive consequence that reduces the frequency of or eliminates a behavior. § This cat’s behavior (scratching the furniture) is
punished by adding an unpleasant outcome (a squirt from a water bottle)
Positive Punishment
© 2016 Cengage Learning.Operant Conditioning
} Negative Punishment: Removing a stimulus from the environment to make a behaviror less frequent.§ E.g., Taking a privileges/objects away from people
is a form of negative punishment.} Other notes about punishment:
§ Consequences have to matter to the person or animal receiving them (i.e., significance).
§ Immediate punishment is much more effective than delayed punishment (i.e., immediacy).
§ Effective punishment must follow uniform application (i.e., consistency).
Negative Punishment
© 2016 Cengage Learning.Operant Conditioning
A Bit of Review
Type of Learning Cognitive Process ExamplesAssociative Form new connections among
stimuli and behaviors• Classical Conditioning• Operant Conditioning
Nonassociative Change the magnitude of responses to a kind of stimulus
• Habituation• Sensitization
Observational Learning by watching the actions and experienceof another
• Imitation
© 2016 Cengage Learning.Operant Conditioning
A Bit of Review
Association between conditioned & unconditioned stimuli
Organism responds to environment
Behavior is reactive
Best with involuntary behaviors Best with voluntary behaviors
Association between behavior & consequences
Organism acts on environment
Behavior is instrumental
Classical Conditioning Operant Conditioning
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A Bit of Review
Add stimulus to environment
Remove stimulusfrom environment
Increase behavior Positive reinforcement Negative reinforcement
Decrease behavior Positive punishment Negative punishment
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Positive Reinforcement
A dog that �begs� is given a treat; it will learn to beg more often.
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Positive Punishment
A kitten that scratches is scolded; it will learn not to scratch.
© 2016 Cengage Learning.Operant Conditioning
Negative Reinforcement
A woman hits the snooze button on her alarm; she will start hitting the snooze button more often.
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Negative Punishment
A girl who breaks a rule has to give up her phone (removing privileges).
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} Continuous§ Every time a behavior occurs
} Partial§ Ratio or interval§ Fixed or variable
Schedules of Reinforcement
© 2016 Cengage Learning.Operant Conditioning
•A fixed ratio (FR) schedule requires that a behavior occur a set number of times for each reinforcer.
•Reinforcers in variable ratio (VR) schedules are given after a fluctuating number of behaviors.
• In a fixed interval (FI) schedule, as set amount of time must pass before reinforcement becomes available following a response.
• In a variable interval (VI) schedule the time interval is allowed to fluctuate around some average amount over the course of a session.
Schedules of Reinforcement
© 2016 Cengage Learning.Operant Conditioning
} Variable Schedules > Fixed Schedules. § FI low rates of responding at the beginning of the
interval and accelerated responding at the end.} Which is better?
§ VR reinforcement leads to rapid and consistent increase in behavior.
§ FR and FI: Behavior tends to drop immediately after a reward, and speed close to next reward.
§ VI reinforcement behavior is slow to increase, but steady.
Effects of Reinforcement Schedules
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Effects of Reinforcement Schedules
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} What happens if you want to increase the frequency of a behavior that rarely or never occurs?
} Shaping via the method of successive approximations§ Begin by reinforcing spontaneous behaviors that
are somewhat similar to the target behavior we want to train.
§ Use gradually more stringent requirements for reinforcement until the exact behavior we want occurs.
Shaping
© 2016 Cengage Learning.Operant Conditioning
• Some, but not all, learning occurs via reinforcement.• Bandura & Social Learning Theory.
• i.e., learning via modeling others’ behavior (aka. observational learning)
• “Bobo Doll Experiments” Children watched films in which a woman beat up the Bobo doll. • E.g., hit with a mallet, sat on it, threw in the air.• Child were then placed them in a room alone with the Bobo
doll and observed their behavior without their knowledge.
• If the children imitated the characteristic behaviors of the model, then learning had occurred.
Bandura’s Experiments
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Bandura’s Experiments
Bobo Doll Video