Chimpanzee “ Language ”

1. Chimpanzee “Language” Psych 1090 Lecture 13

2. The issue of whether animals can truly communicate with humans is incredibly thorny…. The fights pro and con were brutal and, in a sense, doomed the field However, before it collapsed, the work had a stunning impact not only on how we view animals, but also on our understanding of language

3. And I’m going to try to give you just a taste of what happened The work started with the Kelloggs who brought up a chimp, Gua, along with their son, Donald…. and who showed that simple exposure to language wasn’t enough to engender it in a nonhuman primate

4. Hayes and Nissen came next; they trained a chimpanzee named Viki… Although Viki succeeded on a large number of cognitive tasks, she acquired only a very few English labels; Was her failure due to her ‘primitive’ vocal tract or her cognitive skills?

5. The Gardners, Allan and Trixie, watched tapes of Gua and Viki and realized that they could understand everything without sound i.e., that the apes used a lot of gestures They reasoned that maybe one could use ASL, the language of the deaf, to work with the apes

6. They reasoned that ASL would allow them to separate out issues of the inability to produce labels vocally from the possibility of learning a human language Note that, at the time, not everyone agreed that ASL was a true language

7. Some folks looked at ASL as a proto-language; others thought about it in terms of a rationale for a gestural theory for the origins of human language and others began studying ASL for the first time in great detail as a consequence of the ape ‘language’ controversy

8. Were what seemed to be simple signals like “you-me-eat?” representative of a real language, whether produced by humans or apes or were such utterances as primitive as they at first appeared? Until the ape studies, no one seemed to care very much

9. But those issues were to come…First the Gardners started their pioneering work with Washoe Not too long afterwards, David Premack decided to work with a more restrictive symbol system of plastic chips… He trained Sarah to use these chips to communicate with her trainers

10. Sarah with something like “apple same as apple”

11. And fairly soon after that, Duane Rumbaugh, working with von Glasersfeld and others developed a computer-based system of lexigrams that allowed their ape, Lana To function without any human intervention at all, to avoid cuing

12. Original lexigrams were color-coded….

13. One of the later keyboards

14. And, in another lab at Columbia University, Herb Terrace started a second ASL project with Nim Chimpsky Terrace had been trained by Skinner and felt that language could be taught through operant conditioning;

15. Nim did not learn as much as Washoe, And Terrace’s attacks on the field pretty much brought it down But, again, that was in the future and an incredible amount of information was gathered in the interim

16. The basic issue—how did animal “language” differ from human language could only be resolved if we could figure out the limits of the animal’s abilities… AND insure that any animal failure was not a consequence of poor training or vocal anatomy

17. So, that is why I’m going to start with Premack’s 1990 paper even though it’s not the oldest Because he brings up fundamental issues of similarities and differences Between animals’ and humans’ use of symbols… Are they equivalently words?

18. Now, Premack was not the first to worry about concept “word” In 1960, Quine wrote a paper on the topic…he proposed the following: A linguist visits a primitive tribe, and while he is talking to a tribal member, a fuzzy creature runs across their path

19. The tribal member states “Gavagai”…. Our inclination is to assume that “gavagai” is the label for that creature in that culture But, in reality, gavagai could mean any furry critter, anything that is running fast, a generic term for a mammal… Or even lunch!

20. Or, of course, any number of different things…. The point was to make it clear that establishing the referent of a sound pattern isn’t necessarily simple… And that we do it by context, by exclusion, by category…etc.

21. Now, if we have so much confusion about what a word is or means for humans, there is even more confusion about what it might mean for an ape and whether an ape would be mapping human terms onto something already existent in ape terms

22. Specifically, when we train an animal to label something, are we first having to train it to understand the concept of labeling? Or are we just setting up some kind of paired association that has no linguistic function?

23. These are not trivial questions, and fueled the sometimes vitriolic debates And there aren’t any clear, clean-cut answers Although, as we’ll see, Premack’s animals seemed to treat their plastic chips as words…

24. an intriguing study by Lenneberg suggested maybe not… Lenneberg replicated Premack’s chip study with college students, who, not surprisingly, did extremely well on the tasks.. BUT, at the end, had no idea they had learned a ‘language’

25. So you need to keep this all in mind as we discuss the various papers and the various results Remember, all of these apes were trained in very different ways, with different techniques And even Nim and Washoe, both taught ASL, had strikingly different input

26. So let’s go back to part of Premack’s paper…about halfway through, where he starts talking about Sarah’s learning…. After she had acquired a number of labels, she began to learn more rapidly… and, in fact, connected ‘words’ and objects just by having them placed together

27. And, interestingly, we see this difference in our birds… The first label is learned quickly, as a generalized ‘gimme’ The second and a few subsequent ones are learned very slowly, Suggesting that the concept of labeling is what is being learned

28. And then the animals ‘get it’… although naming and requesting are still not separated In fact, this separation is what caused many researchers to use nonreferential food rewards…. The animal supposedly would see the treat as a reward for naming in general

29. But that didn’t happen…animals trained with nonreferential rewards never really understood labels They just learned associations that gave them treats without connecting the label and the object as a name The animals couldn’t usually transfer the label to a similar but not identical item

30. So Premack could show that his animals treated the plastic chips the way children treated vocal labels The real question, still not totally answered, is what the chips—or labels—represent to the ape Let me try to clarify…

31. If I say “unicorn” to you, You know exactly what I mean …. Because you have a full mental representation of the unicorn, even if you had never seen a picture and I said it was a “horse with a horn” But if you needed an association between a label and a physical object in order to represent it….

32. You might not be able to understand what I meant… And that’s what we can’t quite separate out for the animals When is it just a Pavlovian association, like with a lemon and salivating, for you and the animals… or something more??

33. Does real reference require, as Premack suggests, some kind of theory of mind? That is, by using the label “apple”, Sarah theorizes that you have the same mental representation that she has? Tis not at all clear, and has been the basis for plenty of controversy

34. Because simple systems can be simple associations without requiring clear representations That is why Premack used the tests with things like apple stems, to see if these items engendered the same response as his plastic chips The data suggest that the chips may really have been representational

35. Another intriguing issue that Premack raises is whether language training changes how apes think In a sense, any training changes how thinking occurs…. That’s why programs to train students for SATs, MCATs, etc. are so popular….

36. If you “teach to the test”, most students—human or nonhuman—will do better on that test… But they may not do so well on other types of intelligence test…. So there is a difference between practice effects and true re-training

37. And, again, that was one of the problems with Premack’s studies If Sarah finally abstracts the chip that means “color of” And learns brown through a statement “brown color of chocolate” The test of “brown” must be strong

38. But Sarah was given a brown exemplar along with three other already KNOWN color samples So when tested on “take brown” She might still have chosen merely on exclusion…“I know it isn’t red, green, or yellow”…

39. So she would need to choose from a pile that also had purple and silver… And, of course, we run into the same issues of “grammar” as we did with Herman’s dolphins…. Is it just rule-governed behavior, which isn’t exactly grammar?

40. So, for example, Premack’s apes did fine with their usually VERTICAL language with things like “red over blue” But had a terrible time with things like “red under blue” The latter was opposite to the ordering of the chips on the board

41. Such data presume rule-governed behavior, not grammar…. So, keep all this in mind when reading about the language-trained apes that succeeded on certain tasks And the nonlanguage-trained apes that failed…

42. The task with the cut-up fruits and the tubes of water is a good example…. Nonlanguge-trained apes knew match-to-sample… And matches were always identical…. So faced with apples and tubes of water…

43. It wasn’t all that surprising that they were at chance…. They had no idea that they were matching proportions…. Only identity, and nothing was an identity

44. The language-trained apes knew match-to-sample… But also had lots of training where they matched objects to chips So they understood that the objects didn’t have to have an exact match to be correct

45. To them, the partially-filled tube did not have to have the same representation as a plastic chip What the language-trained ape knew was to derive information from such situations So it could respond based on the concept of ‘quarter-ness’

46. In a way that the nonlanguage-trained ape could not…. But language per se was not necessarily the difference Only the way the animal had been trained to respond to certain situations…

47. The same issue probably held with the causality tests…i.e., knife with cut item… It wasn’t necessarily that the nonlanguage-trained apes couldn’t understand the causality They didn’t know how to express what they might have known

48. The analogies test are my favorite because these really ARE a lot like the kinds of tests given in SATs And for which training clearly makes a huge difference in humans… Why not in apes?

49. Sarah would see ?

50. Choice of the correct alternative might be done just by matching the most number of attributes The trials were a bit different for the nonlanguage-trained apes