Innate Learning

1. Innate Learning

2. Romanes • A. was a student of Darwin's • very interested in evolution and intelligence • not a psychologist- more a philosopher/biologist • remember its 1878 • no real data • lots of anecdotes • not really defined variables • his is psychology at the beginning • attempting to distinguish between learned and innate • assume ability to learn represents higher intelligence • lower animals can only survive with INNATE behavior patterns- cannot adapt (that is learn) to deal with new situations.

3. Innate or Learned? • Innate: • animal born w/ability to do behavior • behavior is NOT learned • e.g.- born w/feature detector neurons, ability to see • traditionally, psychologists had little interest in innate behaviors • today: realize the importance of them • many learned behaviors = derivations, extensions, or variations of innate behavior patterns • many of the features of learned behaviors have parallel in inborn behavior • innate behaviors may place limitations on what can learn • focus on goal-directed or goal-oriented behavior: • purposive • characteristic of both learned and unlearned behaviors • need to look at control systems theory to understand

4. Goal Directed Innate Behaviors • Reflexes: stereotyped pattern of movement of part of body which can be reliably elicited by presenting appropriate stimulus ( e.g. patellar reflex- knee jerk) • Sherrington's Principles of Reflex action • threshold of stimulus intensity to elicit response • as increase intensity of stimulus, the latency between the stimulus and response decreases • IRRADIATION EFFECT • RECIPROCAL INHIBITION: coordination between the muscles during reflexes: • most reflexes there for a reason: goal directed behavior: E.G. w/drawal reflex when put hand on hot stove • Tropisms and Orientations: • Tropism: movement or change in orientation of the entire organism • come in 2 major categories: • kineses: random movement • taxes: directed movement

5. Goal Directed Innate Behaviors • Sequences of Behavior: Fixed action patterns • behavior is a part of repertoire of all members of that species • is not due to prior learning • series of behaviors occur in a rigid order • once started, the entire sequence must finish • sign stimulus needed to initiate fixed action pattern: • Reaction chains: • similar to fixed action patterns • different in that: • not have to keep going once start • progression from one behavior to next in series depends on presence of appropriate stimulus • e.g., hermit crab

6. Habituation and Classical Conditioning

7. Habituation Learning not to respond to a previously meaningful stimulus The stimulus used to predict something. Now the stimulus loses its predictability and you ignore it Allows efficiency in learning

8. Habituation Learning not to respond to a previously meaningful stimulus The stimulus used to predict something Now the stimulus loses its predictability and you ignore it Allows efficiency in learning

9. Habituation Learning not to respond to a previously meaningful stimulus The stimulus used to predict something Now the stimulus loses its predictability and you ignore it Allows efficiency in learning

10. Habituation Learning not to respond to a previously meaningful stimulus The stimulus used to predict something Now the stimulus loses its predictability and you ignore it Allows efficiency in learning

11. Habituation Learning not to respond to a previously meaningful stimulus The stimulus used to predict something Now the stimulus loses its predictability and you ignore it Allows efficiency in learning

12. Dishabituation • When the stimulus changes • Signals a change in the situation or setting • No longer appropriate to ignore, as changed stimulus may have meaning

14. Classical Conditioning • Remember the Reflex Arc • Reflex is elicited by a stimulus • Classical conditoning is learning to react to a predictive stimulus • The predictive stimulus predicts the eliciting stimulus • The eliciting stimulus elicits the reflex • Learn to anticipate the reflex behavior so that it occurs to the predictive stimulus

15. Pavlov’s Contribution • Ivan Pavlov • Russian physiologist: Studied salivation • 1901: discovered and wrote about classical conditioning • Found that his dogs reacted to both his presence and the time of day for feeding/experimentation • Researched this: • Measured amount of salivation during baseline: • Present food to dogs • Measure slobber • Then added a predictive stimulus: a Bell • Presented the BellFood • Measured slobber to see if dogs would begin to slobber to the bell

18. Labeled each part of these events: • Unconditioned stimulus or US: • The stimulus that automatically elicited the behavior (usually innate) • E.g., the food elicited the slobber • Unconditioned response or UR • The behavior that is automatically elicited • Unlearned; often reflexive • Conditioned stimulus or CS: • The stimulus that predicts the US • Is a learned (thus conditioned) stimulus • Conditioned response or CR: • The behavior that occurs to the CS • Often very similar to the unconditioned response • Occurs because the CS predicts the US

19. Classical Conditioning Procedure

20. Order of presentation is very important!

21. The CR does not just suddenly Appear, rather it takes several trials Or sessions to learn the connection Between the CS and the US

22. Characteristics or Parametersof Classical Conditioning • Relationship between UR and CR • The UR and CR are not always identical! • Often are similar, or in similar family of behavior • Can be opposite: compensatory response • If predicted to go up, you respond by going down! • See this with drugs: • Morphine = lower BP, heart rate, feeling of cold, less pain • CR to morphine= higher BP, HR, feel hot, more pain • What could be predictive CS for morphine?

23. Characteristics or Parametersof Classical Conditioning • Strength of CR • Gradually increases with trials • E.g., slobber more after each CS-US pairing • Monotonically increasing curve: levels off • Reaches an asymptote: some maximum amount of CR • Why?

24. Characteristics or Parametersof Classical Conditioning • Extinction and Spontaneous recovery • Extinction: If stop CS-US pairing (CS nothing), then the CR will also fade away • Again, must be unlearned, or habituated! • Spontaneous recovery • Sometimes, when conditions are similar to CS, the animal shows the CR • Unpredictable; almost as if they “suddenly remembered” • More likely to occur when animal is stressed, tired, hungry, etc.

25. Characteristics or Parametersof Classical Conditioning • Relearning: • Relearning is faster than original learning • True if extinction occurred AND if just haven’t had the experience for a while • Important for drug, fear reactions! • Generalization and discrimination: • Generalization: CR will occur to stimuli that are similar to the original CS • Discrimination: Can train the animal so the CR only occurs to very specific CSs • Higher Order Conditioning: • Chaining of CSs: e.g., CS3CS2CS1US • Respond most to CS1; least to CS3

26. Four procedures for classical conditioning • Remember: • CS should predict US or no CR • Predictability of CS is critical • Four procedures: • Simultaneous conditioning: • CS and US presented at same time • Delayed conditioning • CS turns off; US immediately turns on • US is delayed until end of CS • Trace conditioning • A delay is inserted between CS and US • Can test “memory” for pairing this way • Backward conditioning • US is presented BEFORE CS

28. Excitation and Inhibition • Each environmental event corresponds to some point on cortex • These are either excitatory or inhibitory effects • Cortical mosaic: complex pattern of excitation/inhibition • Can become relatively stable configuration: • Brain centers that repeatedly activated form temporary connections • Arousal of one area results in activation of related area • Excitation may spread as well (remember Sherrington) • Evidence today for this?

29. Excitation and Inhibition: • Inhibition • during the acquisition of CC- any disruption may prevent the occurrence of the CR on any particular trial • e.g. add a Buzzer---> CS (bell)---> US (food) • Result: no salivation • Palov called this external inhibition: Some external stimulus blocked inhibited the CR • Disinhibition: • during extinction- opposite occurs • any disruption may bring back the CR on any particular trial • Buzzer---> Bell (bell)---> No US (food) • Salivation returns • believed that presentation of distractor stimulus disrupted unstable Inhibitor link that develops during extinction • more stable CS-US association, less affected by distracting S+: supposedly due to changes in excitation levels

30. Excitation and Inhibition: • Measures of Inhibition and Disinhibition: • Summation Test: • superimpose a stimulus on an ongoing response: if the strength of CS decreases, that stimulus is inhibitory • this would show that the CS2 is inhibitory, not that there was a change in excitation, since everything leading to excitation was held constant • Retardation or acquisition test • if its harder (takes longer) to make a stimulus excitatory than some neutral stimulus, then the stimulus is inhibitory • NOTE: that the summation test and the retardation of acquisition test are always done together • Inhibitory Gradient test: • if a stimulus is inhibitory, there will be an upside down generalization gradient around it: • How do you get an animal to respond to these new stimuli to get the inhibitory gradient to elicit the CR? • the inhibitory gradient changes over time: • really, is just discrimination and generalization • learn that some CS = UR, some CS = no UR