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Explore the definition and roots of learning theory, from Functionalism to Behaviorism, Pavlov's reflex studies, and ethical considerations in learning research. Understand acquisition, extinction, and modification of behavior.
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Introduction to Learning Chapter 1
A Definition of Learning • Learning is: • An experiential process • Resulting in a relatively permanent change • Not explained by temporary states, maturation, or innate response tendencies.
Three Limits on the Definition • The change that occurs during learning is a potential for behavior that depends on other conditions. • Learning is not always a permanent change. • What can be learned can be unlearned. • Changes also occur for other reasons – maturation, motivation.
Roots of Behavior Theory • Functionalism – behavior promotes survival, study behavior to understand its adaptive function. • Dewey – lower animals have reflexes, humans have a flexible mind • James – people have instincts • Brucke – internal biochemical forces motivate behavior in all species.
Criticisms of Functionalism • The variety of behavior across cultures is inconsistent with universal human instincts. • Infants seem to have few innate instincts (only fear, rage, love?). • Labeling everything an instinct doesn’t aid understanding much. • Bernard cataloged 2000+ instincts
Behaviorism • A search for the laws governing learning. • Emphasis on experience. • Avoidance of mentalistic concepts. • Based on Aristotle’s idea of the association of ideas. • In order for two ideas to become associated, they must be paired together in time (temporally).
British Associationists • Locke – thinking consists of: • Simple ideas – passive impressions received by the senses. • Complex ideas – the combination (association) of simple ideas (a rose). • Hume – associations are based on: • Resemblance (similarity) • Contiguity in time or place • Cause and effect
Thorndike’s Puzzle Box • http://www.youtube.com/watch?v=BDujDOLre-8
Thorndike’s Laws • Also called S-R learning. • Law of effect – A chance act becomes a learned behavior when a connection is formed between a stimulus (S) and a response (R) that is rewarded. • Law of exercise – the S-R connection is strengthened by use and weakened with disuse.
Thorndike’s Laws (Cont.) • Law of readiness – motivation is needed to develop an association or display changed behavior. • Associative shifting – a learned behavior (response) can be shifted from one stimulus to another. • Once a behavior is learned, the stimulus is gradually changed. • Fish + “stand up”, then “stand up” alone.
Pavlov’s Conditioned Reflex • Conditioning -- a stimulus that initially produces no response can acquire the ability to produce one. • Learning occurs through pairing in time and place of one stimulus with another stimulus that produces a response. • This is a kind of associative shifting, but the response is involuntary.
Terminology of Conditioning • Unconditioned stimulus (US or UCS) • Produces a reflexive response without learning. • Unconditioned response (UR or UCR) • The response that occurs, typically a reflex, involuntary and automatic.
More Terminology • Neutral stimulus • A stimulus not capable of producing an unconditioned response. • Conditioned stimulus (CS) • A previously neutral stimulus that has acquired the ability to evoke a response. • Conditioned response (CR) • The learned response, similar to the UCR, an involuntary reflex.
Two Examples • http://www.youtube.com/watch?v=bOMMy1cmamE&feature=related • http://www.youtube.com/watch?v=F-S2g8CXUAk&feature=related
Conditioning Neutral stimulus CS (tone) CR (salivation) + UCS (food powder) After conditioning CS (tone) CR (salivation) Prior to conditioning (Orientation to sound but no response) Neutral stimulus (tone) UCS (food powder in mouth) UCR (salivation)
Conditioning Processes • Stimulus generalization – stimuli like the CS become able to evoke the conditioned response. • Extinction – if the UCS and CS are not paired, the CS loses its ability to produce a conditioned response. • Spontaneous recovery – an extinguished CS briefly returns but quickly goes away again.
Watson & Raynor • Human fears can be acquired through Pavlovian conditioning. • Rat paired with loud noise • Stimulus generalized to other white objects (white rabbit, white fur coat) • Mary Cover Jones developed counterconditioning -- a technique for eliminating conditioned fears. • Acquisition of fear-inhibiting response
Ethics of Learning Research • Animals and humans are now protected by oversight and ethical guidelines. • Pain or injury to animals must be weighed against and justified by the knowledge to be gained. • Electric shock typically is uncomfortable and upsetting but not physically harmful.
Modification of Instinctive Behavior Chapter 2
Instinctive Systems • Lorenz & Tinbergen – evolution occurs when a species incorporates environmental knowledge into its genetic structure. • Greylag goose and egg-rolling. • Learning can sometimes modify instinctive behavior – even though the fixed action patterns are innate.
Energy Model • Action-specific energy builds up but is blocked (inhibited). • The energy motivates appetitive (approach) behavior. • Presence of a sign stimulus releases the energy by stimulating an innate releasing mechanism. • The behavior occurs as a fixed action pattern (or chain of actions).
Releasing Signs • Releasing signs can be complex: • Grayling butterfly signs include darkness of female, distance from male, and pattern of movement. • Intensity of the sign influences the behavior but so does the amount of accumulated energy (time since the last response).
Hierarchical System • Specific behaviors are controlled by a central instinctive system. • Energy can accumulate at each level in the system. • Hormones generate energy. • Release of energy at higher levels flows to lower levels. • The sign stimulus determines which behavior will occur.
Conflicting Motives • If two incompatible signs appear at the same time, energy flows to a third instinct system. • Stickleback fish begins nest-building when caught in a fight-flight conflict. • This third behavior is called displacement.
Conditioning Affects Behavior • Conditioning experiences can change sensitivity to releasing signs. • Only the consummatory response (eating, mating) at the end of a chain cannot be changed. • Conditioning fine tunes the response to the environment and enhances survival.
Criticisms of the Energy Model • Best viewed as a metaphor. • The brain does not literally accumulate energy in any centers and nothing flows. • Willows & Hoyle – alternating contractions in sea slug allow it to escape from a starfish. • Brain areas producing this response do not correspond to energy model.
Acquired Changes in Response • Habituation – response to a repeated stimulus decreases with experience. • Sensitization – response to a repeated stimulus increases with experience. • Examples: • Ingestional neophobia, fear of new food • Startle response
Experimental Evidence • Rats drink little saccharin water at first but increase over time. • Loud tones (110 db) produce different responses depending on the background noise (60 vs 80 db). • Habituation occurred at 60 db • Sensitization occurred at 80 db • A loud background is arousing, leading to greater reactivity, not less.
Conditions Producing Change • More intense (stronger) stimuli produce stronger sensitization, less likely to produce habituation. • Greater sensitization and habituation occur when the stimulus is repeated frequently. • Changes in the stimulus prevent habituation. • Turkeys respond to shape changes.
Conditions (Cont.) • Sensitization can occur to many kinds of stimuli but habituation occurs only with innate responses. • Habituation and sensitization are transient (go away after seconds or minutes between stimuli). • Except long-term habituation. • Dishabituation – response returns when a sensitizing stimulus occurs.
Opponent-Process Theory • An explanation for addictions. • All experiences produce an affective reaction (pleasant or unpleasant) – called the A state. • This reaction gives rise to its opposite – called the B state. • B state is less intense and lasts longer. • Over time, the A state diminishes and the B state increases.
The Addiction Process • Tolerance – diminished A state. • Withdrawal – increased B state. • Addictive behavior is a coping response to the change in B state. • People try to enhance A state to offset the unpleasantness of the B state. • Without withdrawal symptoms there is no addictive behavior. • Time prevents B state strengthening.
What Sustains Addiction? • The B state is a non-specific aversive feeling. • Anything similarly aversive will motivate the addictive behavior, even if it has no relation to the substance. • Daily life stress produces a B state that results in behavior to create an A state. • Parachute jumpers – create a B state in order to feel the A state.