Studies on Concept Formation

1. Studies on Concept Formation Psych 1090 Lecture 2

2. The definition of ‘concept’, like that of ‘cognition’ is rather flexible and involves many different types of behavior

3. So we are going to examine concept formation from the simplest to the most complex cases And do it for a small (for the moment) variety of species

4. Concept formation, of at least some sort, is a very basic phenomenon Whether consciously or unconsciously, and organism must distinguish, e.g., • predator from prey/ friend-foe • food from not-food • possible mates from non-mates

5. And, in any case, creatures must organize the big, confusing world into some form of workable hierarchy so that attention can be paid, shifted, directed, etc. appropriately for survival

6. One big issue, that we mentioned last time, is whether animals, lacking language, can form concepts and, I said that they can…but now I’ll give some real data

7. We can split concept formation into three major categories…. • object recognition what is or is not a key or a pencil • relational/abstract bigger/smaller; same/different • equivalence/transitive inference A>B, B>C, C>D, D>E……B?D

8. We’ll hold off on concepts like same/different and transitive inference for now… There’s enough just on other areas of concept formation for today’s lecture

9. But even the simplest level, object recognition isn’t really so simple…. Think about the prototypical bird: beak, feathers, wings, flight…

10. But what about

11. Some of these creatures have some bird-like characteristics and are clearly not birds; Others lack some of these bird-like characteristics and clearly are birds

12. And, of course, what might be one important category to a bird Might be two to a human:

13. For a bird, the snakes are ‘functionally equivalent” in that both are predators; But for humans one is dangerous and one is not

14. And although humans can, for example, detect many variations in neighboring white-crowned sparrow dialects, To a bird in a given dialect, all the others are lumped into the ‘foreign’ category,

15. And in different areas, different parts of the songs (e.g., trills versus introductory notes) may be critical for recognition

16. So, one can train an animal like a pigeon to, for example, “categorize” all trees by pecking to picture of a few trees and not to a picture of a bird But pigeons were less easily trained to form the category “car” Something unnatural for it…

17. And pigeons completely failed when asked to categorize one particular oak leaf from among a number of oak leaves…

18. A discrimination not at all important to a pigeon

19. More recently, a number of researchers (e.g., Cerella, Watanabe, etc.) showed that pigeons emphasize local cues So they had considerable trouble distinguishing some, but not others of the following….

20. Pigeons couldn’t distinguish intact versus distorted cubes…

21. TTTTTT T T T T T T TTTTTTT T T T T T T Pigeons could find the “T” in either picture, but not the “H” (Anim. Cogn. 2002)

22. And if given a regular triangle as the positively rewarded choice, and then shown

23. Pigeons chose the trapezoid rather than the occluded item Suggesting that they chose on the basis of just the line figure

24. More recently, Watanabe’s group showed that pigeons can’t really discriminate scrambled from unscrambled cartoon figure heads At least until they got really scrambled

25. 1x1 3x3 6x6 12x12

27. Could discriminate scrambled from unscrambled pictures of pigeon heads

28. And Wasserman’s group argued that scrambling a line figure makes the task more difficult for the pigeon

29. But pigeons seem to have a hierarchy of attention So they may first look for curves versus straight edges And then look for specific types of angles

30. And other studies suggest that motion is a critical factor

31. Some researchers nevertheless argue that pigeons can be trained to do any kind of discrimination, and that may be correct… But the point is that some discriminations are more ethologically relevant and thus are trained more easily

32. Other more subtle issues come up as well…. If you use video for birds, you have to use LCD projectors Because their flicker-fusion rates differ from those of humans, CRT screens are difficult to view

33. And what is true for a pigeon may not be true for another type of bird… Parrots go anorexic in an operant paradigm and stop responding And some hummingbirds, who are win/shift foragers, have real trouble w/ a win/stay operant paradigm

34. There’s the issue, too, of neighbor/stranger discrimination in song sparrows… And how at first some data showed it existed and other data didn’t…. But the real issue was knowing the exact territorial boundary…

35. And, of course, most studies on categorization are done with animals that categorize the world visually, much like humans… But pigeons and people would fail if the criteria were scents…. or subtle auditory cues…

36. And studies of polymorphous stimuli-- where a combination of attributes must be present for an item to be judged as ‘correct’ Suggest that in pigeons the additive features should be ecologically related for success

37. Remember our prototypic bird…if we assume wings AND beaks, X X

38. But if we assume wings AND flight, X X

39. So, how do we go about dealing with such issues?

40. Let’s look at the study on monkeys and humans, Dépy et al. on the conjoined search

41. Training was on marked items [yellow vs. blue was color discrimination, not a bar]

42. The idea was to determine which 2 of 3 qualities, color/shape/location, put a stimulus in C1 or C2

43. I did it by marking C1 as blue, except if blue, round, and down; C2 as yellow, except for yellow, square up So I didn’t match the human subjects in the study, nor did I use the experimenters’ prototype

44. I did it more like the baboons than the humans Of course, I didn’t do it by seeing slides for 800 ms and being told if I were correct or not, either

45. But I would have gotten the prototype right 100%, like the baboons And would matched them on Csl, too

46. So I’m not at all sure one can draw conclusions as to how a particular species does a particular task

47. And, of course, animals will try to succeed however they can… Studies on homing pigeons suggest that they’ll use sight for local features or global features, star navigation, smell, or magnetic currents Depending upon what the experimenters knock out!

48. Thus issues of external validity are extremely important when determining whether an animal is competent or not in any task, and particularly in a categorization task

49. My parrot, Alex, learned to identify a number of objects with English labels He could also generalize from a piece of an index card to a large 12’x18’ piece of paper

50. So we trained him on a set of items, then tested him on variations of these things Differently sized pieces of paper, wood, rawhide, etc.