Variability and Creativity!

1. Variability and Creativity!

2. Comparative Cognition • Evolutionary approach: • cognitive mechanisms evolve in response to selective pressures peculiar to each species’ ecology, physiology and morphology • Thus cognitive processes differ across species • Comparative cognition: • compare abilities across species • Analyze performance of different species on same set of tasks • Focus on species-specific mechanisms and strategies that underlie problem-solving performance • Better to understand how different animals problem solve rather than • Try to determine which animal is “smarter” • Must use a set of tasks, not a single task

3. What behaviors to study? • Relearning • Altering habits and adapting to change by switching to different solution routine • Behavioral flexibility • Neophilia • Exploration strategies • Attention • Motivation • Affordance learning • Physiological constraints

4. Vaughan and Greene (1973): • pigeons trained to classify slides as positive or negative • random- no concept involved • after 10 sessions, could classify 80 slides (40 + and 40-) • learned next 80 even faster • eventually worked up to 320

5. Herrnstein, 1976: • Wanted to see if pigeons could categorize • Three categories: • Trees • Water • Person • Found that pictures being seen for first time (novel) discriminated as well as training pictures • Interestingly- similar patter of errors and correct discrimination across the pigeon subjects

6. What does this mean? • Ability to discriminate open-ended classes of stimuli poses problems at two levels: • Analysis of features enabling subject to tell whether object is member of particular class • Analysis of properties of classes that render them discriminable

7. What are they responding to? • Too complex to be common elements • Cluster of features that are more or less isomorphic-probabilistic conjunctions and disjunctions • Look like semantic categories of generalization

8. Does evolution play a role: • prewired to see trees, water, people? • Presence of static features can be discriminated • More likely that are prewired to form a “schema” or prototype • Tie in with Rosch’s data: inferred prototypes deviate from the simple central tendency of exemplars when the stimulus domains are more natural • Central tendency = best or clearest case/exemplar

9. What do we know about “templates” • new cognitive theories suggesting that we form templates for concepts • Neural networks that “remember” a concept • Result of learning • Could this be what pigeons are doing as well as humans? • Evidence for some prewiring: rules for forming templates: Feature Positive Effect:

10. Crows vs. Parrots • 2 competitive foragers • Parrot: Kea, nestornotabilis • Corvid: Corvusmoneduloides • both have large encephalization quotients, innovation scores • Both show strong manipulation and tool use • Both are social and known for problem solving abilities

11. Importance of tool use. • Question: Does tool use = cognitive ability? • Adaptive specialization for tool use and complex object manipulation = enhanced or impaired performance for other tool use situations? • Tool use allows assessment of problem solving behaviors • Need to parcel out several factors: • Pre-functional development • Associate experience • Affordance learning • Self control • Planning and reasoning about invisible forces

12. Task: • Again crows vs. parrots • Multi-access box: • Food reward is in center of transparent box • Four different routes to food • Train on one, then block; see if birds adapt

13. results • http://www.youtube.com/watch?v=SzEdi074SuQ • First session: • Differences in behavior and number of solutions discovered: • NCC = 0.75 solutions • Rarely touched the apparatus (except string) • Kea found 2.33 • All touched all four opening devices and both tool types • Entrance manipulation: • Kea directly manipulated opening devices more frequently • Crows showed only brief pecking actions at opening with beak or tool • Keas: violent pulling, tearing, rocking, probing, scratching, levering of physical parts of box

14. Results • Sequence of solutions discovered/established • All birds ended up focused on string solution • This was then blocked • But: order of solutions established differed between crows and parrots: • Crows: stick tools, then ball tool then window hook; tended to touch window with stick rather than use stick to pull window open • Kea: ball tool then window hook option; tried the stick option, but failed (can’t hold stick straight given curved beak)

15. Results • Speed of switching between solutions: • Kea was faster than the crows • Tool preference: • All preferred string • Crows = thin sticks • 1 parrot = thick stick • Other parrots: ball

16. What does this mean? • At least one bird in each group able to solve all 4 tasks: shows that birds could solve the tasks • Differences between species: • Keas faster learners, faster switchers, tried more solutions on first trial, showed more individual variation, preferred different tools • Keas also more destructive!: pulled and tore box apart • Crows do use pulling/tearing, but use it for nest building and tool building, not for food retrieval • First evidence of tool use in parrots! • Why? Differences in • Exploration patterns • Affordance learning • Balance between neophilia and neophobia • Kea showed more haptic exploration • Crows (also more neophobic) used more visually guided methods • Neophobia interrupted crows exploratory behavior

17. Reinforced Variability: Alan Neuringer • Animals and people learn to increase or decrease variability through reward • maintained when variability is FUNCTIONAL • that is, variability continues to be rewarded • many people equate variability with ignorance or poor learning • instead, can be sign of good learning and knowledge of situation • variable behavior can be controlled/determined

18. Variability as functional • Indeterminist position: variability = ignorance • Variability cannot be predicted • Cannot be controlled • But: superposition or chaos theory from physics says variability can be predicted/controlled • Skinner: predict operant behavior at level of “class” and not necessarily moment by moment behavior • Really an issue of molar vs. molecular views

19. What is operant variability? • operant responses controlled by reinforcers/ discriminate stimuli • variability indicates continuum from repetition to randomness • random implies that, although relative frequencies or probability of members of set can be predicted, individual instances cannot • thus: responding can be predicted at level of class, but potentially not in terms of individual occurrence of individual behavior

20. e.g.: interresponse variability: • Can animals be trained to respond variably? • Blough (1966) reinforced pigeons for pecking randomly in time • Schwartz (1982): reward pigeons for varying sequence of Left Right key pecking • Didn’t work • not because they couldn’t, but because procedure didn’t reinforce correctly!! • In Blough and Schwartz studies: if responded randomly, received less Sr • Pryor, Haag and O’Reilly (1969): reinforced variability of responding • porpoises • Novel behavior combinations rewarded • Was successful

21. Animals and Humans can Vary • can do with humans, too: • Machado (1989) • Reinforced random runs of responding • Humans quickly learned to vary response patterns • Also: Ross and Neuringer (2002) • reinforced humans for humans drawing rectangles • reinforced for size consistency or inconsistency

22. Variable behavior = Operant behavior? • Appears that variable behavior can come under discriminative control, as well • Page and Neuringer (1985): discriminative cue for random vs. steady responding • Coin toss • Note that must be some “memory” for prior responses in order to respond with high variability • What about physiological sources: how about DA fluctuations?

23. Function of variability • Increase likelihood of contacting reward • shaping • problem solving: try something new if old way not working • Creativity? • Note: in all cases, there is a set of behaviors within repertoire, but unique variation in how these behaviors are put together

24. What about pathology? • ADHD: more variability in responding • Depression: low variability • Autism: low variability • Thrill seekers: high variability • again: could DA play a role here?

25. Implications • Voluntary actions: really just reinforced for random response sequences • Everyday behavior: tends to be stereotyped, but can learn to randomize • Attention may play strong role, as well! Again, DA!!