Computers and Ape Language Psych 1095 Lecture 8
Gill, T.V., & Rumbaugh, D.M. (1974). Mastery of naming skills by a chimpanzee. Journal of Human Evolution, 3, 483-493.
We’ll start with the summary piece about the controversy over ape language I won’t go over all the details, as we’ve been there…but will address some of the newer issues… We haven’t discussed the philosophical issue of how achieving something like language, thus blurring the human-nonhuman distinction formed an undercurrent to the controversy
For people who discount evolution in general, the issue of language evolution is incendiary And, of course, if we can’t really define language, we can’t really separate what humans do—including primitive tribes—from what the apes do…. The first article, written just before the huge NYAS ‘witch-hunt’ conference depicts the issues separating the labs
The ASL labs on one side, arguing that language/communication is a social act and 1) must therefore be taught in a social setting 2) and that lack of a social setting is why the Premacks and Rumbaughs didn’t get ‘real’ language 3) and who cares if the data are anecdotal; so are the data for children
The chip/computerized labs argue that 1) ASL is cued and uncontrolled 2) ASL data are anecdotal and total corpus material is unavailable 3) ASL work is heavily overinterpreted to support what the researchers want to see 4) The social setting is not just irrelevant but bad
The interesting bit was that, as we have seen, Terrace—who used ASL—was not supporting ASL labs…or anyone Gardner and Fouts argue, as we saw, that Nim’s training was not really social or referential (and we’ll see more of the problems later) And that operant techniques gave just what was expected….lack of transfer and no innovation
You can see, too, the acrimony of the arguments…devolving to legal, not scientific, battle… Unless one knows sign and see the original films, one finds the data difficult to evaluate One of the upshots of all this was that the Rumbaughs decided to include social behavior But between apes, not ape and human
The idea was that having the apes interact would reinforce the use of the system as a communicative tool But would avoid having the humans ‘contaminate’ the system with any cues We’ll discuss their experiments shortly… The point of this article was to give you a flavor for the internal warfare that was splitting the field apart…
And papers like that by Thompson and Church didn’t help, either… They constructed a simple computer program that took the initial condition (e.g., food in or not in the machine; Tim present or absent)… And then spit out a relevant sentence Of about 6500 of Lana’s actual formulations, only about 500 were not appropriately modeled…
That is, less than 10%…but they still involved most of the trained sequences So, although Lana did put together some really interesting lexigrams the argument could be made that these were no more common than the anecdotes reported by the Gardners… Except that a computer, rather than a person, logged them onto data sheets
So, as noted above, the Rumbaughs decided to look at a different aspect of communication…. They used Sherman and Austin and instead of dealing with the now-discredited ‘sentence’ concentrated more on the use and meanings of the lexigrams themselves And how the apes could exchange information via these lexigrams
The first thing that the Rumbaughs did was separate requesting from labeling… which turned out to be a LOT harder than they let on in this paper… And actually led to a breakdown in food-symbol correlations… Initial labeling was easy…as you might expect, the apes simply associated the symbol with the food reward..
Initially, Savage-Rumbaugh tried to show the chimpanzees that a label was not necessarily a request by substituting a different food for the one named or, as in many operant paradigms, a single food for all responses These substitutions, not surprisingly, broke the referentiality of the labels… And retraining was NOT as simple as this article states…
These problems are described in separate papers…(and her 1986 book)… Several steps were needed to get back on track… First they tried switching between providing the labeled food and the single food reinforcer… But that didn’t work at all…
Then they tried providing a plastic replica of the labeled food, followed by the single reinforcer food And that didn’t work at all, either Finally, they provided both the labeled food and the common reinforcer food at the same time And then slowly cut back on the portion size of the labeled food, Adding hugs and “good job” as well
What was ALSO critical was that they added two gestures….one involving ‘showing’ and one involving ‘offering”… That is, physical cues….. To separate out the two situations… Just as an aside….we simply required Alex to add “want” for requests And he learned to identify stuff he didn’t want in order to get what he did…
In any case, the training involving the 102 and 201 trials was on the last step only… So much more difficult than they imply And other aspects were a lot easier… Let’s look at the statement “…stating to the animal that a sealed container held one of a variety of foods. If the animal could decode this statement…and request the correct food, we replied “yes”….”
So what the ape saw was the equivalent of The ape then had to ‘request’ the food And it took 5 trials for the apes to learn to do this kind of match-to-sample…
At the time, too, foods were likely to have had a different color background than the locations…. Possibly the difficulty was more in getting them to ask for things they didn’t really want so as to then get rewarded with something they did want… In any case, ‘decoding’ wasn’t an issue at least here
Initially, the animals hadn’t been asked to work with any sort of delay…. Now one ape was asked to wait ~ a minute after seeing a container baited before he could get to the keyboard and state Note that he didn’t yet have to comment about the container
The second ape now had to state And they could share…again, not exactly rocket science… The first ape did have to label, but the second only had to match-to-sample Giving blind tests was a good idea, but the task was still pretty simple
It wasn’t all that much different from the training that they had received, except for the short delay The Rumbaughs did make sure that the ape was not using a position cue, and really could label… which was absolutely necessary… But didn’t ensure that actual information was transferred, only the need to match the symbol
The next step, involving photographs, is really, really odd…. Here the Rumbaughs state that the apes had never been taught to identify photos corresponding to food names… But in the 1980 paper we also read, they describe in detail how they trained the SAME animals to label photographs by taping photos to objects…
What are we to believe???? If they could already identify via a photo the food they had requested via the lexigram… Why did they need training 2 yrs later??? These are the kinds of inconsistencies that never were answered
The next step was intriguing mostly because it got the apes to share food willingly… Here the apes were given what looks like possibly four food items… Tis difficult to see more than the one that is involved in the study…
And, of course, the apes didn’t want to share things like chocolate… So I suspect that they centered on moderately desirable stuff the apes would share… In any case, the communication via the symbols was not much more than one ape labeling X as “x” And the other ape decoding “x” as X
The question that lots of critics asked was whether the apes really were communicating per se Because it didn’t matter if it were an ape, a human, or a machine doing the actions And this paper triggered a really major response by Skinner and his students who did see the project as just match-to-sample and simple association
There are lots of problems with this pigeon paper, but it isn’t just a parody of the ape work… Let’s look at the ‘keyboard’… Jack on the left has actual colors Jill on the right has only symbols
First, the symbols didn’t move around so that Jack and Jill could have learned position cues… something significantly different from the apes Also, Jack and Jill did not trade roles, so that they were even less likely to be communicating than the apes And they were trained individually…
So, Jill was taught, after seeing a special key hit (“What color?”) to poke her head through the curtain, look at a color, and associate the color with R, G, or Y If correct, she was given some grain Jack was taught to hit the “What color?” key, look at a lit button (R, G, Y) and hit the corresponding colored button
If he was correct, he also got grain The birds were actually taught all this via a backwards chain of events, but that isn’t the real issue other than it divorced the meaning of the actions from the actions a bit more The experimenters then put the birds together, so that they took the place of the machines
After they habituated to each other, they began to do what they had been trained to do Waiting for each other to act in place of the machines The researchers also disabled the symbol keys on Jill’s side to control for extraneous cues So what are we to make of this?
You also need to know that the Rumbaughs criticized the Premacks, arguing that the latters’ animals just did matching… But did Sherman and Austin really engage in symbolic communication? The pigeons, because the animals didn’t switch roles, did not… They just meshed independent behavior patterns
But did the apes do that much more? Had they simply meshed the behavior patterns they were taught vis-à-vis their machine… to working with one another? And even if all that was what they did, was it still symbolic because they had to use symbols? Is association learning truly symbolic?
Let’s see how the Rumbaugh’s replied… First, they argued that the pigeons likely simply had positional, rather than symbol, associations…. And that was absolutely true… And although we’ve seen how tricky it is to separate out even symbolic association from real reference the issue for the paper was not use of the lexigrams as symbols
But rather whether the apes were really and truly communicating with each other or had learned a series of associative steps to get what they wanted The Rumbaughs, as we noted, argue that the pigeons didn’t exchange roles… which, again, was true; we don’t know if they could learn both roles
But, again, we don’t really know what the apes understood… The Rumbaughs are correct when they argue that Jack didn’t care how Jill’s light was activated…and vice versa…. But one has to wonder if it mattered to Sherman and Austin, either…. What I don’t understand is that they state that the apes could NOT match symbols…
Match-to-sample is one of the easiest tasks possible it would be really bizarre if Sherman and Austin could not learn that task easily Too, the Rumbaughs argue that Sherman and Austin have much more sophisticated use of their symbols… Which may be true, but those data were not presented in the published paper
The Rumbaughs argue that their lexigrams are much more sophisticated than the R, G, Y keys…. which, again, is true but has little to do with the issue of the paper we read As for the apes’ understanding of gestures versus that of the pigeons… They are basically arguing that the apes can learn nonlinguistic cues, not so different from natural behavior
The additional controls that the Rumbaughs describe…e.g., touching nonsense syllables…were important… So why weren’t they in the paper? The Rumbaughs argue that the symbol enabled the ape to recall what was hidden… But they never tried (say, 5% of the time) touching an incorrect food symbol to see what the apes would do…
The Rumbaughs argue that they did not train their apes… But if the ape did not do what it ‘should’, the food was taken away… which is a form of training And, again, tis amazing that they claim no training on photographs here but do so in a later paper….
Tis also true that apes have great object permanence and that a short delay should not affect how they respond… So they shouldn’t have needed specific training on these tasks… Pigeons might need such training…but that’s an issue of intelligence, not language In sum, there are significant differences in the two studies….
But one couldn’t tell what all of these were from what Rumbaugh’s published And there are some intriguing anomalies… Particularly given the blistering critique that follows in the next article concerning the sign language studies.. What is particularly interesting is their argument about ‘words’…
They argue that Sherman and Austin, because they both produced and comprehended their labels, understood words… But, as we’ll see, Lana did not… And the huge amount of training their animals needed to separate labeling and requesting suggest otherwise They suggest that comprehension/ production skills must be taught separately
I believe such is not the case and was a consequence of their procedures… And, tellingly, they backtrack immensely over what Lana had learned…. Now agreeing that it was simple operant conditioning…. Not realizing that Sherman and Austin’s tasks were only a bit more sophisticated
They are, however, absolutely correct in stating that studies with apes led to much more detailed investigations with children and to a much deeper understanding of what we mean by a ‘word’, a ‘name’, a ‘label’ and a ‘sentence’… and that these controversies were likely to harm the field overall… but they did not back off…
But, before we go continue with the ‘internal’ critics… We need to look at what their criticisms engendered in scientific communities in general… The Sebeok paper is from the popular press, but sums up the witch-hunt very nicely First, it compares the complex signals the apes learned to Han’s hoof-tapping…
Which we know is a bogus generalization.. Sebeok’s claim is that these subtle cues influence ALL such studies and make them outright deceptive What is incontrovertible is that we all emit the kinds of subtle, nonverbal cues that Sebeok describes…. These facilitate normal human communication…
The issue is that there is a huge difference between waiting until a horse stops tapping and cuing an animal to make one of 100 possible signs…or choose one of 4 chips Would it have been better if Sarah had been given a box of chips and the experimenter didn’t know the placement? Probably….