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 – across species. 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 (1690) – thinking consists of: Simple ideas – passive impressions received by the senses. Complex ideas – the combination (association) of simple ideas (a rose). Hume (1748) – associations are based on: Resemblance (similarity) Contiguity in time or place Cause and effect
Thorndike’s Puzzle Box http://www.youtube.com/watch?v=EKvNqe8cKU4&feature=player_embedded http://www.youtube.com/watch?v=BDujDOLre-8
Thorndike’s Puzzle Box
Learning Curve for Cats in Box
Thorndike’s Laws (1898) 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 Studies (1927)
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 Conditioned stimulus (CS) 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.
Example of Classical Conditioning Jim & Dwight – The Office
Prior to conditioning Conditioning After conditioning (Orientation to sound but no response) Neutral stimulus (tone) UCS (food powder in mouth) UCR (salivation) Conditioning Neutral stimulus CS (tone) UCS (food powder) + CR (salivation) After conditioning CS (tone) CR (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.
Acquisition, Extinction, and Spontaneous Recovery
Little Albert (1920)
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 and humans must be weighed against and justified by the knowledge to be gained. Electric shock typically is uncomfortable and upsetting but not physically harmful.
Why Use Animals in Research? People are more complex in their behavior. It is difficult to control prior learning, environment and experiences in people. Some types of research cannot be done with humans: Case histories cannot be used to infer causality. Animals can be lesioned to show which brain areas control behaviors, showing causality.