Learning - Topic 6 - PDF

Learning Chapter 6 Overview  Classical Conditioning  Operant Conditioning  Cognitive Models of Learning Latent Learning Observational Learning Basic Learning  Learning: Change in an organism’s behaviour or thought as a result of experience Learning includes physical chang...

Learning Chapter 6 Overview  Classical Conditioning  Operant Conditioning  Cognitive Models of Learning Latent Learning Observational Learning Basic Learning  Learning: Change in an organism’s behaviour or thought as a result of experience Learning includes physical changes to the brain  Habituation: A decrease in response to repeated stimuli Adaptive  Sensitization: increase in response to repeated stimuli More common for intense, irritating, dangerous stimuli Classical Conditioning  A form of learning in which animals come to respond to a previously neutral stimulus that is paired with another stimulus that elicits an automatic responses Form associations  Pavlov’s pioneering research Investigated digestion Found that dogs would begin to salivate when they heard the footsteps of the feeders  Classical Conditioning  Unconditioned Stimulus (UCS): Stimulus that elicits an automatic response without prior conditioning  Unconditioned Response (UCR): Automatic response to a non-neutral stimulus that does not need to be learned  Conditioned Stimulus (CS): Initially neutral stimulus that comes to elicit a response due to association with an unconditioned stimulus  Conditioned Response (CR): Response previously associated with a non- neutral stimulus that is elicited by a neutral stimulus through conditioning Principles of Classical Conditioning  Acquisition  Extinction  Spontaneous Recovery  Stimulus Generalization and Discrimination  Principles: Acquisition & Extinction  Acquisition: Learning phase during which a conditioned response is established CR increases in frequency over repeated pairings Learning is highest when CS and UCS are presented close together in time  Extinction: Gradual reduction and eventual elimination of the conditioned response after the conditioned stimulus is presented repeatedly without the unconditioned stimulus An active process, not merely “forgetting” Principles: Spontaneous Recovery  Spontaneous Recovery: Sudden reemergence of an extinct conditioned response after a delay following an extinction procedure CR appears, but is often weaker than after acquisition phase Conditioning Processes Other Principles of Classical Conditioning  Stimulus Generalization: Process by which conditioned stimuli that are similar, but not identical, to the original conditioned stimulus (CS) elicit a response Generalization Gradient: the more similar the stimulus is to the original CS, the stronger the conditioned response (CR) will be  Stimulus Discrimination: Process by which organisms display a less pronounced conditioned response (CR) to conditioned stimuli that differ from the original conditioned stimulus (CS) Classical Conditioning  Higher-Order Conditioning: Developing a conditioned response to a conditioned stimulus by virtue of its association with another conditioned stimulus  Example: Pair metronome (neutral) with food (UCS)  Metronome becomes CS that elicits salivation Pair light with metronome  light becomes a CS that elicits salivation  Each progressive level of association results in weaker conditioning Applications of Classical Conditioning Acquisition of Fears and Phobias: Little Albert Study Watson and Rayner (1920)  Wanted to demonstrate that fear was a learned response Used classical conditioning to condition an infant to be afraid of white rats  Albert initially played with the rat – no emotional response  Watson stood behind Albert and struck a steel bar with a hammer – loud noise scared Albert 7 pairings between UCS and CS  strong CR CR persisted after 5 days: white rat still elicited crying/fear  Stimulus generalization: Fear of a rabbit, dog, furry coat  Stimulus discrimination: no fear of cotton balls Applications of Classical Conditioning Disgust: Research by Rozin et al. (1986, 2013)  Would you eat a piece of fudge (or a cookie) that is shaped like feces?  Would you drink out of a glass of juice if a sterilized cockroach had been dipped in it?  Many people in these studies avoided the apparently disgusting stimuli Classical conditioning: CS are quickly linked to UCS (disgusting stimuli)  elicits disgust reaction Applications of Classical Conditioning Classical Conditioning and Advertising  Advertisers pair their product (CS) with the stimuli that elicit positive emotions (UCS)  Latent Inhibition: difficulty in establishing classical conditioning to a conditioned stimulus we’ve repeatedly experienced alone (without UCS)  Operant Conditioning  Learning controlled by the consequences of the organism’s behaviour Response-consequence learning  Examples: Teaching a dog to lay down and roll over using food as a reward Fastening a seatbelt because the warning sound kept dinging  Also called instrumental conditioning The organism “gets something” from the response Operant Conditioning  Law of Effect: if a stimulus followed by a behaviour results in a reward, the stimulus is more likely to give rise to the behaviour in the future A response followed by satisfying consequences becomes more probable A response that is followed by dissatisfying consequences becomes less probable Operant Chamber Operant Conditioning: Terminology  Reinforcement: Outcome or consequence of a behaviour that strengthens the probability of the behaviour Positive or negative  Positive Reinforcement: The presentation of a stimulus following a behaviour that strengthens the probability of the behaviour Appetitive stimulus is given to the organism  Negative Reinforcement: The removal of a stimulus following a behaviour that strengthens the probability of the behaviour Aversive stimulus is removed Operant Conditioning: Terminology  Punishment: Outcome or consequence of a behaviour that weakens the probability of the behaviour  Positive Punishment: administering a stimulus that the organism wants to avoid Administering an aversive stimulus  Negative Punishment: Removing a stimulus that the organism wants to experience Removal of appetitive stimulus Operant Conditioning: Terminology  Operant Conditioning  Reinforcement and punishment are defined according to their consequences Is a punishment really a reinforcer?  Punishment is typically less effective than reinforcement in changing behaviour 1. Punishment only tells the organism what not to do, not what it should do 2. Punishment can create feelings that interfere with learning 3. Punishment may encourage subversive behaviour 4. Punishment may provide a model for undesired behaviour  Punishment can be effective, but should be used sparingly Works best when it is delivered consistently and immediately following undesired behaviour Operant Conditioning Terminology  Discriminative Stimulus: a stimulus that is associated with the presence of reinforcement Sets the occasion for a response  Cues the organism to perform a behaviour because it has been reinforced in the presence of the cue (i.e., the discriminative stimulus)  Examples: Grandparents  child asks for Candy A telephone ringing  answer the phone  Caution: Don’t confuse the discriminative stimulus with stimulus discrimination! Operant Conditioning Terminology  Acquisition: learning phase in which an operant response is established  Extinction: The gradual reduction and eventual elimination of an operant response when reinforcement for that response is no longer presented  Spontaneous Recovery: Sudden reemergence of an extinguished operant response after a delay following extinction  Stimulus Discrimination: the organism displays a less pronounced response to stimuli that differ from the original discriminative stimulus  Stimulus Generalization: the organism shows an increased probability of responding in the presence of stimuli similar to the original discriminative stimulus Operant Conditioning  Schedule of Reinforcement: Pattern of reinforcing a behaviour  Continuous Reinforcement: the behaviour is reinforced every time it occurs, resulting in faster learning, but also faster extinction than other forms of reinforcement  Partial Reinforcement: occasional reinforcement of a behaviour, resulting in slower extinction than if the behaviour had been reinforced continually Operant Conditioning: Schedules of Reinforcement  Two Dimensions of Reinforcement: 1. Consistency of reinforcement: Fixed or variable 2. Basis of reinforcement: Ratio or interval  Fixed Ratio Schedule: a pattern in which reinforcement is provided following a regular number of responses  Variable Ratio Schedule: a pattern in which reinforcement is provided after a specific number of responses on average, with the number of responses varying randomly.  Fixed Interval Schedule: a pattern in which reinforcement is provided for a response at least once following a specified time interval  Variable Interval Schedule: a pattern in which reinforcement is provided at least once during an average time interval, with the interval varying randomly Patterns of Responses Schedules of Reinforcement Overview Operant Conditioning: Shaping  Shaping by Successive Approximations: Conditioning a target behaviour by progressively reinforcing behaviours that successively approximate the target behaviour Operant Conditioning: Types of Reinforcers  Primary Reinforcer: item or outcome that naturally increases the target behaviour  Secondary Reinforcer: Neutral objects that become associated with a primary reinforcer  Token Economies Operant Conditioning Applications of Operant Conditioning:  Animal Training  Parenting  Education  Gambling  Therapy  Combining Classical and Operant Conditioning  Real world learning may include both types of learning (and more!) There are similarities between the two types of learning, but they are usually considered to be distinct  These types of learning can interact…  Example: Fear of dogs Classical Conditioning: Neutral/CS  Dog Paired with UCS  Dog bite CS (Dog) elicits CR (Fear of Dog) Operant conditioning: Avoidance of dogs is negatively reinforced  Anxiety is removed when a person avoids dogs Cognitive Models of Learning  Radical Behaviourists believed that thinking played no role in observable behaviour Behaviour is based on S-R relationships: Classical and Operant Conditioning Principles  S-O-R Psychology: thinking/interpretation matters “O” = organism that interprets the meaning of a stimulus Latent Learning  Edward C. Tolman demonstrated latent learning in rats  Latent Learning: learning that is not directly observable  Tolman and Honzik’s (1930) Maze experiment: Randomly assigned three groups of rats to go through a maze over three weeks Group 1 always received reinforcement Group 2 never received reinforcement Group 3 received reinforcement starting on day 11 Tolman and Honzik (1930) Results  Performance of rats reinforced starting on day 11 (blue line) approximates the rats that were always reinforced by day 13  This indicates the third group had been learning all along They developed cognitive maps of the maze Observational Learning  Observational learning: learning by watching others We learn from “models” Allows for learning without personal experience  Observational learning of aggression Bandura and colleagues Observational Learning Media Violence and Aggression  Correlational Studies: associations between more violent television and aggressive behaviour  Longitudinal Designs: tracked over time, children who were more aggressive show greater tendency for aggressive behaviour later in life  Laboratory Studies: in controlled conditions, people exposed to violent media behave more aggressively  Converging Evidence: Research using different methods points in the same direction