PSY 402

1. PSY 402 Theories of Learning Chapter 2 – Learning and Adaptation

2. Learning Enables Adaptation • The ability to adapt to one’s environment with experience enhances survival. • Those organisms able to adapt were more likely to survive and thus were selected by natural selection. • Example of survival value of a behavior: • Black-headed gulls and eggshells • Kittiwakes who nest on cliffs don’t remove shells

3. Fixed Action Patterns • Fixed behavior sequences that are released by an environment signal. • Triggered by a releaser, also called a sign stimulus • Not learned – built in to the genes, innate • Stereotyped – occur the same way each time and in each person or organism • Eibl-Eibesfeldt considered smiling & eyebrow flashing to be a human fixed action pattern.

4. Modification of Innate Behaviors • Even behaviors that are innate can be modified through conditioning. • Gull chicks get better at pecking at their parents’ beaks to get food – more accurate. • Conditioning experiences can change sensitivity to releasing signs. • Conditioning fine tunes the response to the environment and enhances survival.

5. Acquired Changes in Response • Habituation – response to a repeated stimulus decreases with non-threat experience. • Sensitization – response to a variety of stimuli increases with a single threat experience. • Examples: • Ingestional neophobia, fear of new food • Rats orient less toward light, startle decreases • Chicks are less frightened by shadows flying overhead with repeated exposure.

6. Instrumental Adaptation • Instrumental learning (S-R) occurs when a voluntary behavior (R) becomes associated with a stimulus (S) because of its effect. • Consequences can be either rewards or punishments. • Rewards and punishments are defined by their effect on behavior. • A reward increases behavior • A punishment decreases behavior.

7. Reinforcement • Reinforcement occurs when the association between a stimulus and a response to it is strengthened. • Positive reinforcement occurs when a behavior is rewarded. • Negative reinforcement occurs when a behavior results in avoidance or escape from a bad consequence.

8. Shaping • How can a behavior be reinforced if it never occurs naturally (or accidentally)? • Shaping is a process where a complex or unnatural behavior is learned as a series of steps that are successively rewarded. • By rewarding successive approximations to the desired behavior, eventually the target behavior is learned.

9. Classical Conditioning Adaptation • Organisms learn to recognize and respond selectively to the signals that are important in their environment. • Cues associated with food evoke digestion: salivation, gastric juices, insulin secretion. • Taste aversion learning – illness makes us avoid foods that were eaten just prior to feeling sick. • Food preferences are associated with nutrients.

10. Examples of Conditioning • Popcorn at the movies. • Fear of flying -- stronger with more turbulence (a stronger UCS). • An antelope shying away from low tree branches. • Nausea at the smell of alcohol after a hangover.

11. Territoriality • Environmental cues can become associated with sexual rival males in gourami fish. • Pairing the light with the rival signaled the other fish to prepare so it was able to be more aggressive. • Presenting the light without pairing it with the rival had no effect. • Courtship behavior can also be conditioned, leading to more successful nestbuilding, etc.

12. Fear Conditioning • Freezing is a universal response to threat. • Animals that freeze are less likely to be attacked. • Fear is an anticipatory pain response. • It occurs in response to stimuli that have been aversive in the past and motivates escape or avoidance behaviors. • Fear also releases endorphins in rats who are confronted by the smell or sight of a cat.

13. Conditioning and Addictions • Drugs can be associated with environmental cues present when the drugs are taken. • Instead of the drug response being conditioned, an opposite adaptive response is conditioned that lessens the drug’s effect. • This is called drug tolerance. • Taking a drug under novel circumstances can produce a drug overdose because the compensatory effect is not present (no cues).

14. Sign Tracking (Auto-Shaping) • Sign tracking occurs when a stimulus (cue) in the environment is associated with reward or punishment. • The sign stimulus motivates approach or avoidance behavior because of what it signals. • Negative sign tracking occurs when a sign motivates withdrawal instead of approach. • Some signs signal safety because they mean a bad thing is less likely to occur.

15. Extinction • Associations are learned when they enhance survival, but conditioning decreases when the expected consequence no longer occurs. • Extinction occurs with both instrumental and classical conditioning. • Spontaneous recovery occurs after extinction has been learned, but a break in exposure to the stimulus occurs. • After spontaneous recovery, extinction returns.

16. Timing of Stimuli • The strength of both instrumental and classical conditioning depends on the timing of events. • Reward or punishment must immediately follow the emitted response in order to strongly affect behavior. • Two stimuli must occur close together in time in order for them to be associated with each other.

17. Size of the Stimuli • The strength of both instrumental and classical conditioning also depends on the size of the stimuli. • Larger rewards produce a stronger response than smaller ones. • More intense stimuli are better signals and evoke greater conditioned responses. • More fear, more saliva.

18. Preparedness Affects Learning • Both instrumental and classical conditioning are affected by preparedness (the innate nature of the organism). • Flavor aversion learning is easier with taste cues than with visual cues, but not shock. • Rooting behaviors interfere with learning for pigs trained to put a wooden coin in a “bank”. • Some hamster behaviors are easier to learn.

19. Humans Show Preparedness • Humans show preparedness too, appropriate to our species. • Nausea can be associated with tequila but not with friends or a shot glass. • Snake and spider phobias may be especially prevalent due to preparedness. • People associate shock with spiders or snakes more readily than with flowers or mushrooms.