Learning and Behaviour

1. Learning Enduring change in behaviour Due to experience How something is done Behaviour Procedures and actions performed Learning Non-learning What is done Learning and Behaviour

2. Types of Learning • Habituation/sensitization • Classical conditioning • Operant conditioning • Observational/vicarious

3. Adaptation • Changing conditions • Time scales • Learning only one type of adaptation

4. Innate Behaviours

5. Innate Behaviours • Evolved • Environmental change • Re: Learning • Roots in innate behaviours • Parallels • Homeostasis, reflexes, tropisms, modal (fixed) action patterns

6. Evolutionary Theory • Voyage of the Beagle (1831-1836) • On the Origin of Species (1859) • Artificial, natural, and sexual selection • Adaptation to environment

7. Natural Selection • Variation, inheritance, selection • Differential reproductive success • No intelligent design • Level of the individual • Change over generations

8. Examples: Physical Evolution • Skull • Bipedalism Australopithecus afarensis (400cc), Homo erectus (1200cc), Homo sapiens (1400cc)

9. Examples: Behavioural Evolution • Cooperation (e.g., food sharing, child rearing) • Pair bonding • Altruism

10. Homeostasis • Internal balance of the body • Drives • Regulatory drives

11. Control System • Comparator • Reference input • Actual input • Action system • Output • Feedback system (closed-loop system) • Response lag

12. Comparator Reference input Output Actual input Action System Blood Salinity Eat more peanuts! Drink water! Eat peanuts!

13. Reflexes • Stereotypic movement patterns • Reliably elicited by appropriate stimulus • Survival benefit

14. Example: Grasping in Infants • Humans, other primates

15. Example: Eyeblink • Stimulus (e.g., airpuff) • Eyelid closes

16. Example: Limb Retraction • Sharp rock, hot surface, etc. • Fast muscle contraction • Pulls limb away

17. Reflexes • Rapid response • Simple neural pathways • Sensory neuron, interneuron, motor neuron

18. sensory neuron interneuron ? motor neuron Reflex Arc muscle

19. Tropisms • Movement, or change in direction, of the entire animal • Jacque Loeb • Geotropism

20. Geotropism

21. Types of Tropisms • Kinesis • Movement random with respect to stimulus • Taxis • Non-random (directed) movement with respect to stimulus

22. testing arena heat source Kinesis • Movement in a random direction hot medium fast slow cool

23. testing arena heat source Taxis • Movement that bears some relationship to the location of a stimulus hot cool

24. The Models • Kinesis • Random turn • Set move length • No more than 180° turn • Movement speed variable (fast, medium, slow) • Taxis • Turn so as to move away from heat • Set move length • No more than 180° turn • Movement speed fixed

25. Modal (Fixed) Action Patterns • Originally “fixed”; variable to some degree • Species specific, often state dependent • Sign stimulus (“releaser”) activates a dedicated neural system • To completion in sequence

26. Graylag Goose • Rolls displaced egg near its nest back with beak • Sign stimulus: displaced egg • Remove egg during sequence • http://www.youtube.com/watch?v=vUNZv-ByPkU www.cerebromente.org.br/n09/fastfacts/comportold_I.htm

27. http://www.mylot.com/w/image/1967361.aspx Stickleback Bruno Cavignaux / Biosphoto www.arkive.org/three-spined-stickleback/ gasterosteus-aculeatus-aculeatus/image-A23078.html

28. Supernormal Stimuli • Extreme version of sign stimulus • Size, colouration, etc. • Preference sometimes detrimental

29. Beetles on the Bottle • Gwynne & Rentz (1983) • Male Jewel beetles (Julodimorpha bakewelli) • Colour and reflection of bumps on bottle as supernormal stimuli for female beetle

30. General Behaviour Traits • Behavioural traits strongly influenced by genes • Not the same as Modal Action Patterns • GBTs more plastic than MAPs • No single sign stimulus • e.g., Species Specific Defense Reactions • Freeze, flee, fight • Mouse vs. bear

31. Environmental Interaction • Not strictly genetically controlled • Susceptible to conditioning • e.g., twin studies

32. Behavioural Influence • Selective breeding studies • Artificial or natural selection • e.g., morphine addiction in rats • e.g., Silver foxes • http://www.youtube.com/watch?v=ot2www2CF3Y

33. Habituation and Sensitization Simplest form of Learning

34. Habituation and Sensitization • Changes reflex response • Learning without new axons/synapses • Temporary effect at existing synapse • E.g., less neurotransmitter released from axon terminal

35. Habituation • Decease in a response following repeated stimulus presentation • Note: note everything that results in a decrease in response is habituation Sensitization • Increase in a response following repeated stimulus presentation

36. Example: Banana Slug Habituation • Eyestalk retraction • Touch back • Record time until eyestalks are fully re-extended

37. 25 12.5 Time (sec.) 1 2 3 4 5 6 Trial Results • Slug eyestalk re-extension times • Trial 1: 23 sec • Trial 2: 12 sec • Trial 3: 10 sec • Trial 4: 7 sec • Trial 5: 3 sec • Trial 6: 1 sec

38. Example: Rat Sensitization • 1. Gentle touch, no response • 2. Painful shock, flinch • 3. Gentle touch, flinch

39. Habituation and Sensitization • Generalization: treat other stimuli like learned stimuli • Discrimination: distinguish other stimuli from learned stimuli

40. Spontaneous Recovery • Post habituation or sensitization • Return to original level of responding • Due to passage of time

41. Limits of Natural Selection • Adaptation relatively slow • Generally not helpful during a lifetime • Select best adapted individuals from each generation • Evolutionary time lag • Variation within species

42. Learning: Evolved Modifiability • Selective pressure • Learning • Going beyond innate behaviour patterns • All animals • Evolutionarily selected for • Allows individuals to adapt to rapid environmental change

43. Nature and Nurture • Long debate • British Empiricists vs. Nativists • Not “either/or,” but “both” • Genes and environment constantly interact • Biology and experience both shape an organism’s behaviour patterns

44. The Ability to Learn • A by-product of both heredity and experience • e.g., rats reared in complex environments • e.g., educational aids for infants