exam 2 learning in a natural environment special case... flower learning

1. PART 4: BEHAVIORAL PLASTICITY #18: ASSOCIATIVE LEARNING IN HONEYBEES I • exam 2 • learning in a natural environment • special case... flower learning • odor learning in the proboscis extension reflex • summary

2. PART 4: BEHAVIORAL PLASTICITY #18: ASSOCIATIVE LEARNING IN HONEYBEES I • exam 2 • learning in a natural environment • special case... flower learning • odor learning in the proboscis extension reflex • summary

3. EXAM 2

4. MULTIPLE CHOICE vs WRITTEN EXAMS   …  …   …  …

5. HONEYBEES • order Hymenoptera, family Apidae, Apis melifera • haplo-diploid: queen, haploid drones, sterile workers

6. HONEYBEES • originate in S. Asia, now ~ cosmopolitan • live in highly social, permanent colonies • hive population... 5K to 35K, max 60K workers

7. HONEYBEES • life cycle

8. HONEYBEES • forage for pollen (protein) & nectar (carbohydrate) • fantastic learners • encode complex environmental features in seconds... • remembers it for lifetime • small brain – about 1 mm3 = ~ neurons

9. HONEYBEES • breeding • honey • sting defense • Africanized

10. LEARNING IN THE NATURAL ENVIRONMENT • types of worker bees • cleaners • nurses • hive, undertakers • guards • recruits • foragers • scouts

11. LEARNING IN THE NATURAL ENVIRONMENT • carry pollen & nectar in pollen sacks on hind legs • deposit in hive, communicate with recruits

12. LEARNING IN THE NATURAL ENVIRONMENT • foraging cycle • flight out • at food source • flight back • waggle dance

13. LEARNING IN THE NATURAL ENVIRONMENT • foraging cycle • flight out – visual memory of environment • hover at hive • landmarks during flight • use sun and polarized light • at food source • flight back • waggle dance

14. LEARNING IN THE NATURAL ENVIRONMENT • foraging cycle • flight out • at food source – visual memory of environment • recruits – have olfactory memory of flower • foragers remember physical features of flowers • flight back • waggle dance

15. LEARNING IN THE NATURAL ENVIRONMENT • foraging cycle • flight out • at food source • flight back – visual memory of environment • can be several miles • also use “vector memory” • waggle dance

16. LEARNING IN THE NATURAL ENVIRONMENT • foraging cycle • flight out • at food source • flight back • waggle dance • scout encodes food / sun relationship

17. LEARNING IN THE NATURAL ENVIRONMENT • foraging cycle • flight out • at food source • flight back • waggle dance • @ hive, dances on comb surface (~ language!) • nectar & odor  recruits (~ reward?) • content, distance & direction of flower patch • experiments with robot bee dancers • also for communicating potential new hive site

18. FLOWER LEARNING • flower constancy: bees tend to prefer 1 type of flower • can distinguish 1 flower from another • what physical attibutes? • color? • odor?

19. FLOWER LEARNING • test associating color with reward • feeding station with honey solution • train on 1 color (blue, pink in picture) • test on others • remember paired color

20. FLOWER LEARNING • illuminated disc experiment • train bees to feed with no illuminated disc • test with two different colors, measure preferences • adjust intensity to = • trained & tested on “normalized” colors

21. FLOWER LEARNING • learning curves for different wavelengths of light • bees learn • violet best • others less • blue-green worst

22. FLOWER LEARNING • how long do bees remember? • train: blue light + sucrose • test blue vs yellow • 1 trial training... • stable memory for days • 3 trial training... • permanent memory

23. FLOWER LEARNING • how long do bees remember? • train: blue light + sucrose • test blue vs yellow • stable memory for days • strength different when measured at different times after training • ecological implications

24. FLOWER LEARNING • timing of stimuli + reward critical • color turned on at different times during training • learn color in short time window • 3 s before landing •  2 s after landing • before reward

25. FLOWER LEARNING • timing of stimuli + reward critical • color turned on at different times during training • learn color in short time window • 3 s before landing •  2 s after landing • before reward • sensory memory • ignore later colors

26. FLOWER LEARNING • not only color, shapes & patterns can also be learned • all features  integrated whole • change 1 feature (e.g., odor)  entirely new “flower” • all other features need to be relearned • context important

27. FLOWER LEARNING • not only color, shapes & patterns can also be learned • bees learn complementary patterns...

28. FLOWER LEARNING • not only color, shapes & patterns can also be learned • bees learn symmetry of patterns...

29. FLOWER LEARNING • not only color, shapes & patterns can also be learned • bees learn symmetry of patterns... • trained on patterns... for either • symmetrical • asymmetrical

30. FLOWER LEARNING • not only color, shapes & patterns can also be learned • bees learn symmetry of patterns... • trained on patterns... for either • symmetrical • asymmetrical • tested on patterns... either • symmetrical • asymmetrical

31. FLOWER LEARNING • not only color, shapes & patterns can also be learned • bees learn symmetry of patterns... • learned according to • choice frequency • proximity to correct choice • amount of time at correct choice • what is going on in the brain?

32. BREAK … but first …