Learning

LEARNING Long lasting change in behavior, due to experience Behaviorism • Behaviorism is a worldview that operates on a principle of “stimulus-response.” All behavior is caused by external stimuli (operant conditioning). All behavior can be explained without the need to consider internal mental states of consciousness Associative Learning learning that certain events occur together. The events may be two stimuli (as in classical conditioning) or a response and its consequences (as in operant conditioning). Classical Conditioning • First, we need an unconditional relationship. • Pairs a natural response to a stimulus ✔ Unconditioned Stimulus (UCS) something that elicits a natural, reflexive response ✔ Unconditioned Response (UCR ) response to the UCS Classical Conditioning • Next, we choose a neutral stimulus (something that by itself elicits no response). • We present the stimulus with the UCS a whole bunch of times. Classical Conditioning • After a while, the body begins to link together the neutral stimulus with the UCS. • Acquisition Classical Conditioning • We know learning takes place when the previously neutral stimulus provokes the response. • At this point, the neutral stimulus is now a conditioned stimulus (CS) and the unconditioned response becomes the conditioned response (CR ). Classical Conditioning • Acquisition is not permanent. • The moment the CS is no longer associated with the UCS, we have EXTINCTION. Spontaneous Recovery • Sometimes, after extinction, the CR will randomly appear when CS is presented. Classical Conditioning and Humans • John Watson brought classical conditioning to psychology with his “Baby Albert” experiment. Generalization and Discrimination • Something is so similar to the CS that there is the CR. • Something is so different from the CS there is no CR. Higher order conditioning A new stimulus is associated with a previously conditioned stimulus Think if pavlov paired his bell with a light and the light got a response Taste Aversions • In cases of food paired with nausea & sickness, conditioning is incredibly strong. ✔ even when food and sickness are hours apart • Shows the ability for one trial conditioning Habituation a decrease in response to a stimulus after repeated presentations. Forcing yourself to eat a food over and over again you have an aversion to so you don’t get sick. The Law of Effect • Edward Thorndike • Locked cats in crates • Behavior changes because of its consequences • Rewards strengthen behavior • If consequences are unpleasant, the behavior will stop • Called the whole process instrumental learning Operant Conditioning The Learner is NOT passive. Learning based on consequence!!! Reinforcers • A reinforcer is anything that strengthens (increases) a behavior Positive Reinforcement: • The addition of something pleasant Negative Reinforcement: • The removal of something unpleasant • (aversive stimulus) Primary v. Secondary Reinforcers Primary Reinforcer • things that are in and of themselves rewarding / innately satisfying Secondary (Conditioned) Reinforcer • things we have learned to value (because they are associated with primary enforcers) • Money is a special secondary reinforcer called a generalized reinforcer (because it can be traded for just about anything) Reinforcement Schedules How often do you give the reinforcer? • Every time the desired behavior is exhibited or just sometimes when it is? Continuous v. Partial Reinforcement Schedules Continuous • Reinforce the behavior EVER Y TIME the behavior is exhibited. • Usually done when the subject is first learning to make the association. • Acquisition comes really fast, but so does extinction. Partial • Reinforce the behavior only SOME of the times it is exhibited. • Acquisition comes more slowly. • But is more resistant to extinction. • FOUR types of Partial Reinforcement schedules. Ratio Schedules (Responses) Fixed Ratio • Provides a reinforcement after a SET number of responses. • High response rate, pause after reinforcement • Ex. Factory worker that is paid for every 10 items manufactured Variable Ratio • Provides a reinforcement after a RANDOM number of responses. • Very hard to get acquisition but also very resistant to extinction. • High steady response rate • Ex. gambling Fixed Ratio- She gets a manicure for every 5 pounds she loses. Interval Schedules (Time) Fixed Interval • Requires a SET amount of time to elapse before giving the reinforcement. • Moderate response rate with long pauses after reinforcement • More frequent at anticipated time of reinforcement • Patient-controlled doctor timed pain relief. • Test every 2 weeks Variable Interval • Requires a RANDOM amount of time to elapse before giving the reinforcement. • Very hard to get acquisition but also very resistant to extinction. • Moderate and steady response rate • Ex. Email, facebook , pop quiz Fixed Interval: She gets a manicure for every 7 days she stays on her diet. Punishment • A stimulus meant to decrease a behavior Positive Punishment • addition of something unpleasant. Negative Punishment (Omission Training) • removal of something pleasant • Punishment works best when it immediately follows behavior and is harsh! + Positive Reinforcement Punishment Gives something to increase the likelihood that the behavior will be repeated (the subject wants this thing/condition) Gives something to decrease the likelihood that the behavior will be repeated (the subject does not want this thing/condition) Negative Takes something to increase the likelihood that the behavior will be repeated (the subject does not want this thing/condition) Takes something to decrease the likelihood that the behavior will be repeated (the subject would like to have this thing/condition) How do we actually use Operant Conditioning? • Sometimes, we use a process called shaping. • Shaping is reinforcing small steps on the way to a desired behavior. These small steps are called approximations. Chaining Behaviors • Subjects are taught to link multiple responses together in order to get a reward. Token Economy • Every time a desired behavior is performed, a “token” is given. • They can trade “tokens” in for a variety of prizes (reinforcers) • Used in homes, prisons, mental institutions and schools. Contrasting classical and operant conditioning • Classical conditioning – Links two stimuli together through association. – Involves a natural, biological response. There is no decision made – Pavlov’s dogs salivated naturally, biologically, with no decision of their own. • Operant conditioning – Links a behavior to its results. – There is a decision made here to do or not do a behavior. Behavior that gets reinforced is more likely to be repeated. Latent Learning • Edward Tolman – demonstrated the concept using rats/mazes & reinforcers. • Learning doesn’t completely depend on consequences. • Learning is not always immediately observable in behavior (“latent” means hidden). • cognitive maps – a mental representation of one’s environment Insight Learning • Wolfgang Kohler - Chimpanzees / Boxes & Bananas experiment • Learning takes place through the “ah ha” experience (gaining “insight”). • Weakens the behaviorist argument (emphasis on external, behavior / consequence relationship) Learning from others • Mirror neurons fire when an animal acts and when the animal observes the same action being performed by another • Observational learning: learning by observing others or learning without direct experience or our own. – Might be why we like sports • Modeling the process – How we learn skills via observation observing and imitating a specific behavior Observational Learning • Albert Bandura - BoBo Doll experiment • Children imitated the modeled behavior of attacking the doll • Social Learning Theory 1. 2. 3. Observational learning The impact of others towards new behavior (reinforcement or punishment Observing the rewards and punishments of others • Implications of Bandura’s findings? Learned Helplessness • Martin Seligman – Dog/Electric Shock Experiment • hopelessness and passive resignation in an animal or human • occurs when unable to avoid repeated aversive events Other learning terms • People and animals have biological predispositions, meaning we’re naturally good at some things and bad at others. – Animals easily learn to associate things that help them to survive. – And, animals don’t easily learn things that don’t help them survive.