Classical Conditioning & Reinforcement PDF

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Kristin Pauker...

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What is Learning? ❖ Relatively consistent change in behavior due to experience ❖ Nonassociative learning (one cue): ➢ Habituation: decrease in behavioral response after repeated exposure to a nonthreatening stimulus ➢ Sensitization: increase in behavioral response after exposure to a threatening stimulus Classical Conditioning ❖ The classical conditioning “recipe” ➢ US ------> UR ➢ NS ------> US ------> UR ➢ CS --------------------> CR ❖ Here’s an example: ➢ US --------------------> UR (choppy waters) → (nauseous) ➢ NS -----> US -------> UR (boat) → (choppy waters) → (nauseous) ➢ CS --------------------> CR (seeing a boat) → (nauseous) ■ US = Spicy Food ■ UR = Perspire from the spicy food ■ CS = Seeing the restaurant ■ CR = Perspire automatically from the spicy food Pavlov’s Experiment ❖ Food (US): Salvation (UR) ➢ Reflexive response ❖ Tone (neutral S): nothing ❖ CS is repeatedly paired with the US ➢ A tone is dounded before the food is presented ❖ Eventually, the CS elicits a new CR. ➢ Classical conditioning is complete when hearing the tone by itself causes salivation. ❖ Terminology of Classical Conditioning ❖ Neutral Stimulus (NS): Any stimulus that does not naturally elicit a response associated with the UR ❖ Conditioned Stimulus (CS) ❖ Conditioned Response (CR) ❖ The Classical Conditioning “recipe” ➢ US --------------> UR ➢ NS --------------> US ------------------> UR ➢ CS ----------------------------------------> CR

❖ Acquisition ➢ Initial learning with pairing an association that normally didn’t exist. ❖ Stimulus generalization: tendency for the CR to be elicited by neutral stimuli that are like, but not identical to, the CS. ❖ Stimulus discrimination: ability to distinguish, or discriminate, among stimuli similar to the CS and to respond only to the actual stimuli. (learning only certain associations) Not all associations are created equal ❖ Biological preparedness: ➢ Animals programmed to fear certain stimuli ❖ Contrapreparedness: ➢ Inability for certain stimuli Conditioning in the Brain ❖ Learning to be afraid ➢ Information registers in the brain ➢ Amygdala reacts ➢ HIppocampus helps store associations with context ➢ Amygdala triggers fear response Can classical conditioning explain ALL learning? ❖ No, classical conditioning requires an involuntary response or reflex to exist. ➢ What about when behavior involves a voluntary  response? Three kinds of associative learning ❖ Classical conditioning ❖ Operant (or instrumental) conditioning ➢ The process whereby a behavior becomes associated with its consequences  ➢ Involves voluntary behavior ❖ Observational learning Trial & Error Learning ❖ Positive response from what you wanted to happen The Law of Effect ❖ The survival of the “fittest” response ❖ Fittest is defined by reinforcement ➢ Satisfying actions repeated ➢ Unsatisfying actions die out ❖ At no point is there insight. Operant Conditioning: Skinner Forming superstition ❖ Reinforcement is random Negative: Minus, subtract, take something away (nothing to do with positive or negative situations)

Reinforcement: Increase Cleaning Reinforcement: Cleaning + Positive

- Negative Reinforcement: Removing something in order to reinforce the cleaning

Punishment: Leaving mess

Increase Behavior

Decrease Behavior

Pay roommate $10 for putting away clothes.

Blast Celine Dion every time she leaves dirty clothes on the floor.

Increase Behavior

Decrease Behavior

Stop reading your bio textbook out loud when roommate puts away clothes

Hide your roommate’s cell phone every time she leaves dirty clothes on the floor.

Decrease = Always taking away something Increase = Always adding something Reinforcers ❖ Primary reinforcers: Inherently reinforcing (e.g., food, water, relief from pain). ❖ Secondary reinforcers: Learned reinforcers; do not inherently satisfy a physical need (e.g., praise, money, good grades). Reinforcement Principles ❖ Follows same laws as classical conditioning (e.g., acquisition, extinction, spontaneous recovery, generalization, discrimination) ❖ Shaping: ➢ Gradually reinforcing closer and closer behaviors EXAMPLES Whenever David hits his little brother, his mother doesn’t let him play outside, now he hits his little brother less. ❖ Behavior: Hitting his brother ❖ Increase or decrease: decrease ❖ Adding or taking away: adding (+) ❖ Operant principal: positive punishment Nani feels crummy every time she skips exercising. Because she wants to avoid feeling crummy, she is motivated to exercise on a regular basis. ❖ Behavior: exercising ❖ Increase or decrease: increase

❖ Adding or taking away: taking away (-) ❖ Operant principal: negative reinforcement Nani wants to exercise more regularly. So she decides to give a trip to her favorite frozen yogurt place for each week she exercises three times. ❖ Behavior: exercising ❖ Increase or decrease: increase ❖ Adding or taking away: adding (+) ❖ Operant principal: positive reinforcement Continuous vs. Partial reinforcement Schedules of Partial Reinforcement ❖ Ratio: Based on frequency of responses ➢ Fixed Ratio: Always reinforces after the same predictable number of behavior. ➢ Variable Ration: Reinforced after unpredictable # of behaviors. ■ Gambling: Unpredictable; how many times you pull a slot machine until you get the prize ❖ Interval: Based on length of time ➢ Fixed Interval: Reinforced at predictable time intervals ■ Mail: Mailman comes at 3 PM, always knows he comes around that time. You’ll check when it’s closer to that time. ➢ Variable Interval: Reinforced an unpredictable time intervals. ■ Email: Can come at any time. Classical vs. Operant Conditioning ❖ Classical Conditioning ➢ Association between CS and CR ➢ Depends on original involuntary association ❖ Operant Conditioning ➢ Association between response and consequence ➢ Involves voluntary increase or decrease in behavior ❖ Shared Features ➢ Acquisition, extinction & spontaneous recovery ➢ Generalization and discrimination Cognitive Learning ❖ Acquisition of info not immediately acted on but stored for future use ❖ Latent learning: takes place in the absence of reinforcement ➢ Tolman’s rats: cognitive maps ❖ Insight Learning

➢ “Aha” experience ➢ Sultan the chimpanzee ❖ Observational Learning ➢ Observational Learning: The learning that occurs through watching another perform a behavior ❖ Bandura’s social learning theory: ➢ Modeling ➢ Bobo doll study What is memory? ❖ Memory: Capacity to retain & retrieve skills & knowledge ➢ Essential to identity ➢ Record of experience in the mind ➢ Rarely perfect ➢ But helps us function everyday Memory: Information Processing Model ❖ Memory includes three processes: ❖ Encoding: Getting information into memory in the first place. ❖ Storage: Retaining memories for future use. ❖ Retrieval: Recapturing memories when we need them. Memory: Atkinson & Shiffrin’s model ❖ We have three different memory stores, or sets of neurons that maintain information. ❖ Each memory store has a different: ➢ Duration - the length of time information is maintained ➢ Capacity - the amount of information that is maintained. ❖ Sensory Memory: Brief representation of the world being processed in the sensory system. ➢ Brief duration (less than 1 s), big capacity ❖ Short-Term Memory (STM): Working memory -- contents of memory that you are aware of at any moment ➢ Short duration (up to 30 s), limited capacity ➢ Info must be rehearsed or will be lost What is the (limited) capacity of your STM? ❖ Miller’s magic number: 7 (+/-2) ❖ Chunking can improve this (8321141 vs. 838-1141) ❖ Long-Term Memory (LTM): Relatively permanent memories stored for long durations (hours to years) ➢ Long durations and unlimited capacity ❖ Primary Effect: First three words that were listed in the series of words. ❖ Recency Effect: Last three words that were listed in the series of words....