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

languageI 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

distinctionformed 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 and1) 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 see4) 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…

Initial labeling was easy…as you might expect, the apes simply associated the

symbol with the food reward..

And actually led to a breakdown in food-symbol correlations…

Initially, Savage-Rumbaugh tried to show the chimpanzees that a label was

not necessarily a request by substituting a different food for the

one namedor, 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

actionsAnd 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 otheror 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

easilyToo, 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

publishedAnd 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

chipsWould it have been better if Sarah had

been given a box of chips and the experimenter didn’t know the

placement?

Probably….

But apes do not follow eye gaze (work by Tomasello) and generally the chips were so close together that eye gaze

wouldn’t helpA box would have solved the argument

that Sarah was watching for the experimenter to relax as she chose the

correct chip…A serious problem is that communication

is a SOCIAL act…

Take away social interaction, and what do you have?

An animal that is trained operantly, knowing only associations…

We’ve never been able to get the correct balance…

to avoid criticisms of cuing but keep the communication system intact…

Where Sebeok goes off the deep end is to compare the work w/ psychics

Sebeok’s criticism of the Gardners’ double-blind is also off-base…

Arguing that the experimenters could ‘guess’ what was being shown….

by ESP??

Even if Washoe gave evidence, by lip-smacking, that the slide was of food,

MANY food slides were being shown…

Other criticisms involve how the observers might have seen something

or changed their answers….

which basically amounts to calling the Gardners liars

As for cuing with the Rumbaugh’s system…

Could the apes have watched for a cue as they searched for a lexigram?

Possibly, but supposedly the experimenters couldn’t see the

keyboard, just the final choices…

And supposedly the keyboard had lots of lit buttons, not only the 11 food

buttonsBut we are never told that in the

journal articles…

Is there a kernel of truth in the Sebeok’s arguments?

Yes…and had they stuck to that kernel, their criticisms would have

been constructive…

And might have led to the appropriate controls….

But they went sooooo overboard that they were dismissed—

except by the large number of folks who wanted to discount the studies

So let’s look at the Rumbaughs’ paper that is their equivalent of Premack’s

‘word’ paper…

A sort-of response to critics…

Here they are talking about categorization

Can an ape learn a hierarchical system such that all x’s are X and all y’s are Y

Even if x’s are keys, sponges, rakes, etc. and y’s are bananas, bread,

cheese…

Of course, the issue is edible vs nonedible—a bit simpler than other

categories…And what they only briefly allude to is that, for Sherman and Austin, the tool

labels were functional, not object labels…

That is, the lexigram

was what you hit when you saw a lock; it didn’t necessarily mean ‘key’

So that they couldn’t look at a key and choose the correct lexigram…

Lana, however, was taught the objects devoid of their use, so she had trouble

figuring out that connection…

All the animals were taught this task in many very small steps…

First to sort physical foods and tools

Then to associate one lexigram with the foods and another with the tools…

Not exactly rocket science for an ape

Then they were taught to place the food and tool lexigrams

appropriately…Then shown novel foods and tools and asked to signify if stuff were edible or

not…

Getting such a concept shouldn’t be too difficult

Lana, however, couldn’t do this….

She seemed, actually, to have exchanged the labels, given her

results…(3/10)She was tied to the labels, in a sort of

mutual exclusivity….

It’s an It’s always been

Why should I label it as…

Lana’s second round is even more interesting, when she got 1/10…

Such data do seem odd…

Then we are treated to the photograph work….which contradicts the earlier

paper

Again, the apes had to be trained to sort the lexigrams into food or tool use

We don’t know how long this training took

Eventually, they passed a test showing they could sort novel food and tool lexigrams appropriately…

Into something that represented an edible or not…

The data show good comprehension of the individual lexigrams, but not

necessarily ‘food’ and ‘tool’…

Red and green bins would have worked, too

Does the paper show some neat behavior?

Yes…but maybe not as neat as the Rumbaugh’s would like us to believe..

And Lana’s inability to transfer from labeling to comprehension is telling…

We see it with our parrot Griffin, who wasn’t taught properly….

And it’s not the issue of Grif’s intelligence but our deliberate

training…

So let’s end up with the Rumbaugh’s criticisms of Nim…

They start by, correctly, identifying pre-representational use of symbols

from representational use….

the early associative connections that occur even in young children…

But then, interestingly, they argue for a controversial step…

That of the signaler making sure that the signal has been received…

Something Sebeok would argue involves cuing

Can you have it both ways ???

They make an issue of referential pointing….

something apes don’t seem to use in the wild but do learn in captivity…

The underlying issue is joint reference…

Something that is critical for child, chimp, and parrot, and I suspect other

critters…Baldwin and others have shown that if

you jointly attend to an object with another individual

and label that object in joint attention

the individual learns the label….

The child, however, has to be about 15 mos old to engage in joint attention on

a routine basis

And one would expect that such behavior would have to develop in

other creaturesFor younger humans, the caretaker

does the work…

Figuring out the focus of the child’s attention and labeling, etc…and by 9

mos the child will maintain the attention

So, again, why wouldn’t such behavior develop in apes?

We see it develop in our parrots…

The Rumbaugh’s arguments that many apes find it difficult to expand their

labels

is central the issue of mutual exclusivity that we just discussed…

Category labels need to be added as additional, not alternative labels…

“This is a key, it’s a green key”

“This is a key, it’s a tool to use this way”

Such is true for children as well as nonhumans

As for adding labels…well….

A young signing child probably wouldn’t do much different from Nim’s

“you me Nim sweet drink gimme”

except maybe to eliminate the “Nim”

particularly if there was a choice of things to request…

The arguments about comprehension hold a bit more water…

We didn’t see too many tests that required Washoe to choose an object…

But neither did we see it for Lana…

With my birds, we found that we had to be very careful when we did tests to see if a request was meaningful…

If you request an apple and I offer you chocolate…you might take it!

And if each time you requested a banana I offered you an apple,

you’d start to conflate the symbols

So you have to put in only a few probes and balance the desirability of the

choices

And even then, you can’t be sure of what is happening… apple,

banana….maybe you don’t care

I hope you all carefully read the transcript of the training that Nim had…

Because if this was representative, I’m amazed that Nim learned anything…

The trainer asks him to sign to get an apple slice; he could care less…

When he finally asks to eat apple, she doesn’t respond

He’s learned that signing doesn’t get him what he wants

She then tries to teach him the label “slice”

So he mimics what she does; she doesn’t accept his sloppy attempt…

She tried to mold his sign to improve it; she ignores his attempts

He responds “sorry” when he sees her sign things that he knows are

reprimandsMaybe no contrition, but he has some

associative understanding…

Now she gives up on “slice” and makes him place the apple next to the other bit

of apple

He still doesn’t get anything but “good”

If you were Nim, would you understand that this is a matching

task?

Now she tries to get him to label the banana slice…

He asks to eat it and she ignores him

Then he sorta signs banana and she gives him a piece…

The trainer does not consistently demonstrate—or label—that she wants

Nim to match….

Sometimes she lets him eat the fruit, sometimes she doesn’t….

How is he to understand what is going on??

Think about training in which there had been a clear demonstration of the task

With the use of a label “match”…and no use of ‘slice’—which muddied things

even more….

The Rumbaughs’ training is at least quite consistent…

But we really don’t know if, given a choice of foods, one of their apes would

indeed choose what he requested…

And share as long as he doesn’t want it himself..

I could not find video of Sherman and Austin performing these tasks…

I hope you also read the transcripts closely

In 7/11 of the first trials described, the apes use pointing gestures to show what

they want….

Not good statistically to show symbol and keyboard use….

In the next set, 6/14 trials also either do involve sharing or involve points…

Better, but still not exactly what you’d expect for the system to be working

Note that these apes were trained on these behavior patterns

And the symbols used here probably were not novel ones

The Rumbaughs here are trying to avoid the issue of experimenter cuing by letting the ape subjects interact…

which is a neat way of designing the experiment when the animals

cooperateBut, again, we can’t be sure that all the labels function appropriately; the apes may or may not really want what they

requestTho’ they do know how to respond to a

lexigram

There are other papers that we won’t read that show that the apes can bring the appropriate tool to one another…

First the apes were taught the function of several tools…

for example, a key to open a box, a wrench to open a pipe with a wingnut on

the endNext they were trained to request the tool from their trainer via a lexigram

Next they had to give a tool when shown the lexigram…

Note that each step was trained independently and took a lot of training

What might have happened if these steps were trained together?

The Rumbaughs didn’t figure the apes could understand such complexity

And, by this time, why didn’t the apes connect tool and lexigram easily?

Now they separated the apes so they couldn’t communicate at first

While separated, one ape is shown a food being hidden in a container

And the container requires something like a key to open a lock or a stick to

push things through

And that ape requests the needed tool from the other ape

If the second ape does indeed decode the lexigram and bring, e.g., a key…

They both get to share the food…

But what is actually happening in terms of their understanding of their actions is

unclear…

Could one ape be replaced by a computer?

I’m not being facetious….the issue is whether this is real communication…

And it’s not a simple issue to solve…

In yet another study, the ape had to look at a food in one room,

Identify it via lexigram in another room

And then comes back in and points…

He gets the food only if the lexigram and the point match

This would be indicative of displacement IF the apes had done this

on their ownBut they needed significant amounts of

training….

Even though the delay was quite short

What did they make of the task?

Were they confused that they had to do the additional point?

How can we tell?

How many of Nim’s failures were due to incompetent training?

Or maybe the possibility that Nim wasn’t a particularly intelligent ape?

How might Nim have reacted?

We haven’t really discussed the possibility of individual variation in the

different animal subjects….

One would expect that animals vary just as humans….

That most of them are ‘average’…but that some are Einsteins and some are

pretty stupid

And researchers couldn’t choose their subjects

Colleagues of mine at the Portland Zoo tried signing as enrichment with one of

their apes…

The animal barely learned anything

If that had been the only ape to be trained, the field would never have

gotten going…

No one gave an ape an intelligence test before starting to work with it

I also want to talk about a somewhat less appealing set of reasons for all the

back-biting in the area…

After the 1980 election, a huge shift occurred in the amount of funds

available for research

NSF funding rates, for example, which had been about 25% (25/100 grants

funded)dropped to about 10%

Thus everyone was really scrambling to get a piece of the remaining small pie…

And the mentality was that clobbering others in the field might improve one’s

own chances

What happened, however, was that everyone lost funding..…

Panels decided that we didn’t know what we were doing at all and other

areas were more worthy

The Rumbaugh’s survived from funds from Georgia mental health subsidies

because, as we saw in the video last time, their work was directly applicable

to help children with disabilities

Premack decided he didn’t want to deal with all the craziness and shut down

I got small grants from a private foundation thanks to Don Griffin

Another issue was the crazy publicity…

The huge initial excitement was well beyond what you could imagine…

Even tho’ we didn’t have immediate internet access to the material

Every magazine and TV ran stories about the work

And that engendered a lot of anger and envy

Imagine yourself as someone who had spent 20 years doing operant

conditioning on rats and pigeons

and you might be considered the best in the area…

But your face and animal were not the lead story on TV nor was your work

published in Science routinely

Nor were conferences inviting you to keynote…

In such an atmosphere, any mis-step at all would not only be observed

but would be the source of a lot of gloating and, again, major publicity

Articles like the Sebeoks’—ones that damned the research because the

researchers could conceivably find a way to cheat—

were accepted and praised

That’s not to say that there weren’t problems….

But had folks gotten together and had conferences to talk about how they

could cooperate to FIX the problems….

The story might have turned out differently

At one point, interestingly, Terrace was put on the Rumbaugh’s payroll…

And suddenly he starts writing articles that are relatively complimentary…

He rightly argues that the study we read about food and tool should be

expanded to include location and drink

So that it’s not edible vs non-edible

But accepts Rumbaughs’ claims that the work is proceeding without seeing

any data (which hasn’t been highlighted anywhere)

Terrace argues that the Rumbaughs’ apes do not demand things of each

other spontaneously….

But it’s not clear that they ever needed to do so….

Would have been interesting to see if they fed only one ape…the dominant

one…And if the subordinate begged using a symbol rather than a natural gesture…

Terrace was extremely positive when discussing the food-sharing

experiment…Even tho’ we saw that initially the apes pointed and didn’t use the lexigrams…

He is still somewhat critical that apes do not use any symbols simply to comment

on their environment…

But one wonders how he’d react if they did….

For example, Alex may comment that his birthday cake is ‘yummy’ or that his corn is ‘cold’ or beans are

‘green’…Obviously appropriate comments….

But would these comments be considered just chatter because they

differ from children’s comments,

which tend to direct a caretaker’s attention to something new

And he is extremely laudatory about the work with a pygmy ape, Kanzi…

And we’ll spend much of the next lecture discussing how Kanzi differed

from the regular chimpanzees

Not only with respect to species differences but also with respect to

the different type of training he received…

with successes and attendant critics

Not too many papers have come out in the last few years…

So we’ll stop about a decade ago…

At least in terms of assigned reading…

I’ll briefly discuss some newer material in the lecture…