Dolphin Cognition

1. Dolphin Cognition Psych 1090 Lecture 13

2. Now, we’ve talked a lot about birds, nonhuman primates, even insects… but barely discussed cetaceans, which are also large-brained, long-lived creatures and for which lots of data exit

3. So we’re going to do a brief survey of these creatures; we could take many lectures and barely get through the data We’ll start with some of the two-way communication studies and end with what looks to be mirror self-recognition

4. Dolphins had always held fascination for humans, even from the time of the ancient Greeks but it was really around the 1960s that researchers started studying them scientifically First looking at their natural whistles, learning that they had sonar

5. And only a bit later was there the attempt to engage them in direct communication studies with humans Lilly was one of the first to engage in such work; He trained dolphins to match number of and trains of sound bursts, interburst silences, and latencies

6. He pretty much used standard operant techniques and fish rewards His subjects were also able to differentiate between one human’s voice and other humans’ comments or corrections And he manage to train the dolphins to produce a few human-like utterances

7. Unfortunately, Lilly became known more for LSD experimentation and total deprivation studies But his work set the state for a number of other intriguing studies People like Karen Pryor trained dolphins to understand certain signals

8. Not just the typical stuff of marine mammal shows, but signals such as “invent” For which the dolphins would do some entirely new behavior or combination of behavior Other researchers examined how dolphins might transfer information to each other

9. How, for example, they could do particular jumps exactly in tandem or transfer information about what was in their tank to another dolphin in an adjoining tank In the early 70s, the person who became most influential in dolphin research was Louis Herman

10. Who looked at all the work being done with signing chimps and computer-mediated communication between apes and humans And decided to replicate the work with dolphins He worked in two modalities…hand signals and artificial whistles

11. His system was quite similar to that later adapted by Ron Schusterman for Rocky, the sea lion Basically, the animals learned to respond to a series of signals, either auditory or gestural And thus could be examined on how well they comprehended this artificial language

12. So the dolphin would be given a set of signals that would mean “flipper touch the ball” (i.e., not the frisbee or the ring) And it would swim to the ball in the pool, ignoring the ring and the frisbee and carry out the appropriate action

13. The animals were trained via operant techniques, with food rewards… Once they got the hang of the system, they began to learn new symbols much more rapidly Often simply by the use of mutual exclusivity, or “exclusion”

14. So if they were to learn the novel label “buoy”, They would watch experimenters throw already known objects/labels such as a frisbee and a ring into the tank, And then be told to “fetch buoy”

15. They knew what a frisbee was and what a ring was… So, by exclusion, they would fetch the buoy… And thus make the connection between the novel sign and the novel object

16. When Herman moved into production, life got much more difficult Mainly because he separated out production from comprehension And didn’t use referential rewards, first looking at just vocal reproduction

17. What he did was to get a good baseline of the vocalizations already in his dolphins’ repertoire… A critical important first step Then he trained the dolphins so that they understood that they had to replicate whatever came next

18. Nevertheless, it took over 1000 trials to get the dolphins to replicate the sounds And they ran into even more trouble when they tried to get the dolphins to associate these sounds which were learned in the total absence of a referent, with specific objects

19. What they did was to give the dolphin the sound along with the object at first They hoped the dolphin would make the association and produce the sound in the presence of the object But the dolphin wasn’t getting the “replicate” signal, so it didn’t act

20. So then they tried giving the dolphin the replicate signal along with the signal and the object Which worked fine, except that the dolphin wasn’t really ‘labeling’ the object Just replicating as taught

21. So they tried fading out the signal they wanted the dolphin to use as the label So it heard “replicate this”, a less loud signal, and saw the object Well, the dolphin was smart and knew it was supposed to replicate exactly what it heard…

22. So, as you might imagine, it began to produce the imitated signal in a softer and softer manner…. which was exactly the opposite of what Herman wanted The humans finally figured out a kind of alternation system that worked

23. But the training was painfully slow Nevertheless, the animals did learn to use these signals with striking accuracy, if extremely slowly This work is in rather stark contrast to the paper we read by Reiss and McCowan..

24. Here the dolphins had a lot of control over what they wanted to do And they were actually given the choice of whether they wanted food, a toy, or interaction with their trainers By using an underwater keyboard system

25. Initially, Reiss would touch the key The dolphins heard a signal And then something appeared in the tank

26. The keyboard was then presented to the animals during specific sessions But they did not receive any specific training other than the demonstration of how it worked The young males were extremely curious and explored it

27. Note that at least in this experiment, the older females were not much interested Which could be an important point Herman’s subjects were older females Too, Reiss’ young males often monopolized the keyboard

28. So, when we look at the results, we have to keep all that in mind… We don’t know what would have happened had the experiment been done with just the adult females Or with females that weren’t actively involved with their calves

29. Or what Herman might have been able to do if he had had young males And, although my gut feeling is that the training techniques were really the issue That’s a hypothesis that needs testing very carefully

30. In any case, Reiss’ data were strikingly different from that of Herman’s…. The dolphins started to reproduce the vocal signals after fewer than 20 exposures And the productions were often made separately from the sample

31. The dolphins would produce the whistles BEFORE they hit the appropriate key Or when they were playing with the appropriate object in the absence of the keyboard Suggesting that they had easily made the connection between whistle and object

32. The dolphins also remembered these whistles over a two year period And upon reintroduction of the keyboard, started using the whistles immediately Suggesting a strong association, at least, between the whistles and the system

33. Of particular interest were the whistle combinations…. When the dolphins, while playing with both rings and balls, took + Note frequency levels

34. to produce, in context, Note that the ball bit is up near the 16 kHz…so it’s not a ring blip

35. And there was an 82% correlation between the combination and combination play Suggesting that this was a real association But not one that was trained; it was a spontaneous combination and spontaneous use

36. In fact, none of this was trained… If nothing else, the data suggest something about the flexibility of vocal learning in the species Even if, like birds, this flexibility is more pronounced in youth

37. And, because there was no selective reinforcement of particular aspects of the vocal behavior We can see what is likely salient to the dolphins…. Frequency modulation, duration, harmonic structure

38. And, of course, it is fascinating to see parallels with respect to primacy and recency effects The dolphins learning the beginning and ends first… Much like humans and the birds that we’ve studied

39. Now, Reiss and McCowan are very careful not to claim full referential communication here… And rightfully so, given that the animals were not tested directly on whether they could label Nor on how well they might be able to transfer to really novel balls or rings

40. And, of course, the study stopped (for lack of funding) well before the researchers could look at more sophisticated sign combinations For that, we have to look at some more studies by Herman Here he stuck to the gestural communication trained with Ake

41. Basically, Ake had learned what Herman called a syntax and what in a series of back-and-forth in-print arguments Schusterman called rule-governed strings which actually is a very important distinction…

42. Because syntax implies true correspondence with human behavior And the dolphins did not have anything nearly as complex…e.g., no passives or past tense, etc.. But the dolphin did have to follow some fairly complex rules in deconstructing the gestural strings she was given

43. So, for example, “hoop ball in” means “put the ball inside the hoop”… That is, in. object-dir. object-verb, in a recency pattern so that what is acted on is closest to the verb This pattern was chosen specifically to link the verb and the object to be acted on

44. It also meant that the dolphin had to distinguish things like “hoop ball fetch” from “ball hoop fetch” But in many cases there could be no real reversal…you can’t put the hoop in the ball But, instead of looking at that non-reversal issue as a drawback,

45. Herman decided to use it as an advantage to see what exactly his dolphin did or did not comprehend and what types of errors she might make when given impossible directions to carry out

46. Interestingly, when Schusterman did a similar study on a sea lion, the sea lion pretty much did what is could with what it was given… Often, tho’ not always, reinterpreting the commands so as to do something related

47. It isn’t clear, of course, if the dolphins, who we will see, often balked at an anomalous command should be considered smarter than the sea lions… The latter maybe should be given credit for their innovative attempts to deal with something odd

48. Ake also had some modifiers, such as left and right And the order there was also important, so that the modifier modified the term directly to its right… “pipe left ball fetch”

49. So, a dolphin being given anomalous phrases could have quite a number of different thing ‘go wrong’… Syntactic anomalies could be something like the verb in the wrong place… “over surfboard” or “ring over surfboard”….

50. These are the kind of errors a tired human trainer might make, reverting to English in this case Of course, the use of the term ‘syntax’ really needs to be considered just a short-hand It isn’t syntax like yours or mine