sea lions and parrots: smaller brains, equivalent abilities psych 1090 lecture 15
Post on 21-Dec-2015
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TRANSCRIPT
A few years after Herman began publishing his work on the
dolphins,
Schusterman decided to see what a smaller-brained marine
mammal might do….a sea lion
Schusterman was also trained in the behaviorist tradition
And, to make sure that his techniques would match those of
Herman,
he went out and actually studied with Herman for awhile
And decided to use the gesture language because it required less
hardware
He trained a sea lion, Rocky, to do most of the same things that Ake and Phoenix had learned to
dowith basically the same grammar
to act on various items— “frisbee over” meant jump over the
frisbeeAnd also taught some relationals
So, like the dolphins, Rocky could understand when to take the
frisbee to the surfboard
and when to do the reverse action
Unlike Herman, Schusterman also taught Rocky relational terms…
Bigger/smaller, lighter/darker
Relational terms are really important because they are totally context dependent
As we talked about in earlier lectures, what is bigger on trial 1
can be smaller on trial 2
so the subject cannot answer with respect to absolutes;
the subject has to understand the concept that is being tested
And, of course, the subject has to be able to transfer to new
exemplars without any training
And Schusterman and Herman were different in other ways…
They got into quite a battle about ‘grammar’…
Herman insisted that what his dolphins were doing was
grammar…
In fact, one of the reasons he started the research was to show
that a nonhuman could learn grammar
But Schusterman argued—correctly—that what had been
learned
was rule-governed behavior…
The first step toward grammar, but nothing quite as complex as
what humans use
As an aside, birds engage in such rule-governed behavior in their
complex songs
and any animal, bird or mammal, and like early humans,
that combines a vocalization with a gesture in a standardized
manner
is engaging in a primitive grammar:
A standardized rule-governed behavior that enables efficient
transmission of information
They then continued to “duke” it out, arguing over what is or is not
grammar in their subjects,
Using “anomalous” commands
Now, we talked about the anomalous commands for
dolphins awhile backand mentioned that Lana would
‘erase’ anomalous sentences from her computer
and we saw that Kanzi would carry out semantically stupid
actions that were grammatical…
Only Schusterman tried to make sense of all this
in terms of conditional discriminations and something
called equivalence class formation
The latter is, according to some researchers, the basis for human
linguistic competence
Now, we’ll get back to equivalence when we discuss the
results of Schusterman’s experiments
But now is probably a good time to introduce the concepts BRIEFLY
and why it is thought to be important
And, as usual, a source of controversy!
In some ways, equivalence is just a special form of transitive
inference
Only instead of using, e.g., “bigger/smaller”, it uses
“equal to”
So, if A=B, B=C, A?C
Which suggests that any animal that can do TI should very easily
be able to understand equivalence
Of course, as with TI, a lot has to do with how the subject is trained
or exposed to the stimuli
And, of course, there are fancy terms for the various
relationships
We’ll get to all that later…for now all we need is to
understand what Schusterman means by “functional
equivalence”…
Which is basically that Rocky understood that some signs related to objects, some to
actions and some to attributes
In human language terms, nouns, verbs, and adjectives
Note that Schusterman is looking at a very simple form of
equivalence here…
Just hierarchical categories of how the signs relate to the sea lion’s
world
And, an aside…at one point, Schusterman used two-handed actions for one type of sign and
one-handed actions for another…
I’m not sure that he kept to this, but at least in the beginning it would have been an important
cuesimplifying what the animal had
to learn…
So, in the paper on anomalous sentences, the issue was how
Rocky would respond
If the sign from one functional class was placed in the spot
normally reserved for another functional class
or if something was missing in the sentences she was given
Basically, she would balk if given something that didn’t make
sensethough sometimes she’d do what
she could with what she was given
Suggesting that she understood enough to know that these
weren’t right
Interestingly, she balked appropriately if, for example, an
object was missingbut did what she could when a
modifier was missing
Of course, she had learned to work with objects before they had been
modified…
which may have mattered…
Also is not clear if her dropping first anomalous modifier had to
do more with memory…
But anyway you look at the data, Rocky had some idea about what was going on…
She never performed randomly on nonlabeled items
But whether she had learned a real syntax was still not clear…
Was she balking when an action was missing because of syntax
or just because she had been trained to station until she saw
a verb?
In terms of conflicting modifiers, Rocky did about 3/4 with respect
to recency…
Given that only a fraction of trials were reported, this was probably
statistically relevant…
But not as strong as argued in the discussion
And, of course, as noted by Schusterman, all that Rocky did
was to enable her to get the most fish per session
So, were these actions that she performed meaningful in any real
sense?
Or just actions to be performed in particular ways for food?
Such questions can, of course, never really be answered….
But they were asked by everyone who argued against the results of these ‘animal language’ studies
And, of course, the arguments between the researchers didn’t
help
Now, such arguments were, in one sense, very good and
importantBecause a field can’t grow and we
can’t learn from our mistakes if the mistakes aren’t found
The issue is whether there should be a chance to fix the
mistakes and continue
I didn’t choose to assign the papers where Herman and
Schusterman go after each other
They are referenced in the papers that have been assigned for those
who are interested
I’ll just briefly go over the bit we did read…
In many ways, Rocky did not differ all that much from the
dolphins
Although Schusterman does see differences….
Primarily with respect to reinforcement issues…
As stated, dolphins were ‘paid’ to guess and the sea
lion was not
which again brings into focus how different types of training
regimes result in different outcomes
And the importance of experimental design
While I don’t see either set of experiments as really telling us all that much about the actual
ways in which the animals process information…
I do see that there isn’t too much basis for a pure linguistic
interpretation
Just like the starling-recursion discussion …
IF you argue that failure on a task demonstrates lack of linguistic
knowledge
Then you have to accept that success does demonstrate
linguistic ability…
But the real issue is whether the task really was the crucial
one…
Note, the issue is not whether the CONCEPT was the crucial one…
It may still be….
But the task chosen to represent the concept
AND exactly how the task is taught to the subjects
e.g., the tamarins were exposed to the task and the starlings
taught…
And these are the same issues here for the dolphins and sea
lions
And this brings us back to the equivalence issues….
And whether one can actually analyze language from the standpoint of equivalence
Or if equivalence is one of several issues
So, let’s talk about what all the terms in equivalence
mean
and how they might relate to language….
for humans and nonhumans alike
So, we start with reflexivity, A=A
Which is just another fancy term for identity match-to-sample
And, we have seen, most animals are pretty good a learning that
and transferring it to totally novel stimuli
Although for some animals what is shown during transfer is just a savings in trials needed to ‘get it’
compared to the number of trials needed to learn the original task
But, basically, it isn’t rocket science
The next part is symmetry and that is a bit more difficult
Because not only is it a conditional relationship…
that is, “if A do B”, but also “if B do A”
Many nonhumans have trouble with symmetry
But nonhumans can indeed be trained to respond to
symmetryIt doesn’t however simply
emerge from their initial if A then B knowledge
And it really isn’t entirely clear that it emerges for children
either
And, of course symmetry is what underlies a lot of what language is
about….
Because comprehension-production require symmetry….
And, as we saw, sometimes animals taught only production couldn’t comprehend and vice-
versa
The animals’ abilities may have had more to do with the way
they were trained than with their innate abilities
But you can see why the issue of equivalence is so critical to
language
A subtle point that is not addressed except by Premack,
however,
Is whether even knowing that A and B are related by symmetry
means that A is a symbol representing B
You could see how just accepting that A and B are interchangeable doesn’t mean they are symbolic
representations
Think of it this way…I can give you a token for a cup of coffee, or
vice versa
But the token doesn’t represent that cup of coffee
Unless I know otherwise, the token can instead represent $1
And that’s one of the big issues in the idea of training many
equivalences….
Because many things can, for example, cost $1, but the $1
doesn’t really represent them…
Except in an odd, basic sense
But let’s go on to transitivity
that is the equivalence form of TI…
So that the subject, trained on A=B and B=C can, without
training, understand that A=C
But, again, are we talking about real symbolization or not?
We can see how it might relate to language…
in the sense of “key” (the vocal label) = KEY (the written label) =
= “key” , etc
But, as with the $1 example, you can see how the issue becomes
clouded…
Now, some researchers argue that equivalence is a prerequisite
for language
Others argue that language is a prerequisite for equivalence…
If you could show equivalence in a nonlanguage trained
animal
Or only in a language-trained animal
You might answer the question one way or the other…
But it is never easy
Now, initial studies on various animals suggested that they
couldn’t understand equivalence relationships
If they had been trained, that meant that equivalence didn’t
emerge spontaneously
Was it their abilities or the training?
Schusterman argues that training is ok…
As long as the animal can transfer to novel situations
Which makes sense, because the animal has to learn what it
is that we want it to learn in the first place
Of interest in this paper was that the previously language-trained
animal
was the one that had the most trouble and had to be dropped
Suggesting some kind of dissociation between
language and equivalence…
Or between what was previously taught and language….
Quite possibly, Rocky didn’t understand why there was a
major switch
Hand signals used to be the command and now pictures
were being used
And for Rocky, the hand signals connected to objects and
actions
And now all that were available were the pictures
The set up was what we saw in the videos with Rio on Sci Am
Now, they used arbitrary symbols and not letters or
numbers
And the sets differed on different trials
So A could be a circle and B could be a plus sign
The point was that no particular sample was right or
wrong,
But depended on what was being trained
So she learned 6 sets of two items so as to understand the
pairings between them
But for 24 sets, she was not trained on the symmetry
relation
So there were a bunch of pairings for which she knew
only to choose novelty
And, again, at first she had to choose novelty
But then she was trained if she saw the relatively novel
itemShe had to choose its pair
And she was trained on 6 such pairs
Then there was training for A-C and C-A
With review training on the A-B and B-A sets
But only for the samples that had been set aside for training
She could then be tested on the sets that had not be trained for equivalence
To see if she had somehow understood what should go in
which group….
Remember, she had been trained on all objects in one direction
So what was being trained was whether she understood the relationships with respect to
their categories
It is as tho’ I trained you
Q 5
Obviously, Rio had a large number of these types of trials
And lots of reminders of what was connected to
what, at least in one direction
And, when tested, she did quite well…
The assumption was that she had learned the
concepts of symmetry and transitivity
And not just paired associations
Because the pairs were always in one direction and she was tested in opposite directions
One can argue that by the end of all this training that the associations were just
lumped
So that radio-tulip-crab was just some grouping distinct
from car-rose-fish
But that is what is meant by an equivalence class
That the objects do become connected and the
interconnections are solid
Even if the interconnections are not specifically trained
But, of course, what this has to do with language is still kind of iffy
What it does show is that Rio had some kind of representation
of the sets
She was, for example, never shown that car and fish were
relatedOnly that radio and crab were
related via tulip
And had to deduce that rose did the same for car and fish
The suggestion is that such representation abilities underlie
language
But, of course, these abilities may simply be needed in order
to survive
And have been co-opted for language
The same kind of issues are involved in the mutual
exclusivity article with my birds
Is the ability really language related
or just something that is used much more basic that is co-opted
to help with label acquisition?
I start by arguing that ME is considered a human strategy
mainly because the folks studying children argued for ME
to be uniquely human…
The question is to what extent is ME a basic strategy for learning
So, let’s look at what ME generally is….
When children are first learning labels
Their initial rule seems to be not only that every item has a
labelbut each item has only ONE
label
That is, they see the labels “turtle” and “animal” as
mutually exclusive
Of course, if children were stuck in this stage,
they’d never learn appropriate hierarchical concepts or categories
And thus they outgrow it fairly quickly
But, in the early stages children—like Premack’s apes—will use
ME to help them learn
And not just object labels but also, later, attribute labels
Well, the child definitely knows that a shoe is “shoe”
Probably hasn’t seen a hole punch like that one
And, by exclusion, will take the hole punch and assume it is the
dax
When then given
And asked to “find the dax”
They won’t go for novelty again but take that hole punch
Thus they engage in what Susan Carey initially called “fast
mapping”The child might not understand
that “dax” refers to hole punches in general
But at least was able to associate the novel object and the novel
word from pairings with familiar ones
Now, the issue is really important because a dog seems to have done something similar
But children seem to be able to do this type of behavior for ‘dax’ and ‘wug’ at the same time (i.e., for two essentially novel items
And the dog wasn’t tested that way
And when Schusterman’s sea lions were tested after
supposedly learning a label-object connection via ME
that is, by being given a mix of novel and familiar items and told
“take the dax”
They failed…needing 200 trials to get it right
Now, for children, ME may sometimes help them learn that
the strange label is for an attribute
So, if they are playing with an oddly colored ball
And told that it is chartreuse
They may infer that chartreuse is the color of the ball
But that part of ME comes later in development
and I called that bit “attribute deductivity”
to separate it out from ME proper
But that’s what I really wanted to study…
Essentially, if you look at the ball-chartreuse issue
You are indeed giving the child an alternate label for the same
item
Now, that’s not what I had done with Alex…
Alex Alan Alda
“woodwood” “keykey”
I had trained him that several different UNCOLORED things
could be called “wood” or “keys”
““green wood”, “green green wood”, “green key”key”
But then when it came time to train him on, say, colors
I simply used the color as an additional label
Not as an alternative label
And I used two different items that had the same color
And actually trained a novel category label as well…
So Alex saw me, using the M/R technique, work with a student
and say things like
“That’s green wood; the color is green and the matter is wood”
We structured the training so that ‘green’ was unlikely to be
considered an object label
An, interestingly, we used the same question “What’s here?”
all the time
Only if an item had color did he have to give the color
He didn’t seem to have any ME type issue
He learned the label just about as quickly as he learned any
other object label
And although he sometimes made generic errors…
calling a colored object by just its object label
He didn’t make too many such errors
And, he very quickly learned to label other items with the
appropriate colors
and learned several other color labels and used them appropriately as well
So he seemed to understand how objects could have multiple labels
But did that mean that, unlike children, he didn’t have ME?
Or did his behavior have more to do with his training…
that is, using the attributes as additional labels, so he didn’t see
them as alternative label?
And thus had no problems…
What would happen if we trained birds in a way that more closely
resembled the ways in which children experienced items?
So that they saw lots of differently shaped (like Alex) but also
differently colored (unlike Alex) items
all given the same labels….
That is, once they labeled all these colored keys as “key”,
Then I wanted them to label them just “yellow”
Like the children, an alternative rather than an additional label
I’ll stick to Griffin, because Alo was having behavior problems (had been abused before coming into
the lab)
We trained Griffin on colors separately from objects…
via a computer screen
That in and of itself made it more difficult for Griffin to label
the colors
Because he didn’t get anything he could handle, just the ability
to request a treat
But he did eventually get them
But when it came to getting Griffin to transfer his color
labels to his objects
He had major issues
He couldn’t immediately transfer and actually had to be trained,
slowly and painfully
And, when given a new object…plastic cups…that came in
various colors…
He refused to learn the label “cup” and insisted on giving its
color
Even to this day he won’t label “cup”
And, interestingly, children who are actually given lots of
information like “This is a dog; a dog is a kind of animal”
like Alex, rarely exhibit ME
Whereas most children respond like Griffin
So training is extremely important in terms of how
learning occurs…
And might help children with dysfunctions who have trouble learning labels for attributes
But what does this mean for the concept of ME?
Most likely, ME is a special form of general information
processing
Even pigeons and rats, given tasks that have nothing to do
with language
exhibit something called ‘blocking’
Which, in brief, means if they have learned to make a particular association
say a tone and some food,
they find it more difficult to make the association between light and
the food
One way of figuring things out would be to see if Griffin could learn a new set of categories
with training like Alex…
So far, he is resisting….
But we keep trying…
Now, there are other parallels between nonhumans and
humans with respect to label acquisition
And these get into even more complicated areas
Such as brain maturation
Greenfield (1991) posited that control of such Greenfield (1991) posited that control of such parallel development initially resides in a parallel development initially resides in a
single neural structure (roughly Broca’s area) single neural structure (roughly Broca’s area) that differentiates as a child maturesthat differentiates as a child matures
In children, object and vocal label In children, object and vocal label combinations arise at about the same time in combinations arise at about the same time in developmentdevelopment
Want Want more more cookie…cookie…
In language-trained great apes, In language-trained great apes, object and signed or computer-object and signed or computer-
generated combinations also arise generated combinations also arise at about the same time in at about the same time in
developmentdevelopment
Want more Want more tickletickle
So let’s look in some detail at what Greenfield was
considering combinations
and what such combinations actually
meant
Pairing is equivalent to “more + Pairing is equivalent to “more + X” or “want + X”X” or “want + X”
According to Greenfield, According to Greenfield,
Potting is equivalent to “want + more Potting is equivalent to “want + more + X” but the child could also say “X + + X” but the child could also say “X + want + more”want + more”
Subassembly implies understanding Subassembly implies understanding that “want + more + X” is made of that “want + more + X” is made of “want + more” and “more + X”“want + more” and “more + X”
Greenfield and colleagues (Johnson-Pynne et al. 1999)
argue for a homologous neural substrate in apes
and suggest the possibility for monkeys…
They trained Cebus monkeys to do the cup-stacking task
The training occurred painfully and slowly, but did occur
Interestingly, Cebus have some limited combinatory behavior in
the wild
They combine two actions and sometimes two calls
So, the researchers argued that all this had relevance for the
evolution of language…
A primate system, in which humans and apes were
language-able
and monkeys showed some precursor ability
That is, one might conclude that parallel development of communicative/ physical combinatorial acts initially controlled by a purported single neural center is
likely unique to primate evolutionary lineslikely unique to primate evolutionary lines
provides support for the motor/gestural provides support for the motor/gestural theory of language evolutiontheory of language evolution
not unique to humans, not unique to humans,
is the beginning of primate language-is the beginning of primate language-like syntactic developmentlike syntactic development
And basically everything else could be ignored….
All the combinatory work with the dolphins and sea lions
And, of course, no mention of creatures so evolutionarily
distant from primates as birds
A student had been cleaning up the lab and put lots of bottle caps on the counter where Griffin was sitting…
She heard a bunch of clanking and looked up to find
Griffin putting one cap inside another and dumping them on the
floor
Now, Griffin was already saying things like “want nut”
and “want corn”
He had learned these from watching and listening to Alex
And seemed to understand “want X”…
So we couldn’t examine the emergence of 2 object and 2
label combinations…
but what about 3 object and 3 label combinations?
He wasn’t yet doing either of those things
Griffin’s data for combining objects:Griffin’s data for combining objects:
Method AttemptsMethod Attemptsaa SuccessesSuccessesbb
Pairing 233 217 74 38 29Pairing 233 217 74 38 29
Pot 12 7Pot 12 7
Subassembly 6 0Subassembly 6 0
a a Any effort made to combine objects; Griffin had 16 failures. Overall number of Any effort made to combine objects; Griffin had 16 failures. Overall number of trials was 251; 244 of these were with three objects.trials was 251; 244 of these were with three objects.
bb A stable assembly. A stable assembly.
cc Griffin picked up and put down a successful assembly; no further manipulation Griffin picked up and put down a successful assembly; no further manipulation
dd Successful assembly tossed off the counter. Successful assembly tossed off the counter.
ee Any other manipulation of assembly (e.g., destruction); includes trials in which he, Any other manipulation of assembly (e.g., destruction); includes trials in which he, for example, flipped internal cap over while it was inside external cap).for example, flipped internal cap over while it was inside external cap).
UnitUnit Pick up Throw Pick up Throw
ManipulateManipulate
Note that Griffin also frequently
picked up objects side-by-side
placed caps over bits of food
placed objects into large plastic rings
balanced small objects on large ones
Now we had to train him form some 3 label combinations….
So we chose 2-corner paper/wood and 5-corner
paper/wood
In the space of the study, he learned only one of those
But we taped him when he was playing on his counter
And found that he could produce a large number of different combinatory vocalizations
Most of which we—nor Alex—never used nor trained
Two-label combinationsTwo-label combinations Three- or more label Three- or more label combinationscombinations
want pawant paaa green cornergreen corner want pop cornwant pop corn
want walnutwant walnut green nutgreen nut want corn nutwant corn nut
want corkwant cork green beepergreen beeper want grain nutwant grain nut
want grapewant grape green water green water want cork nutwant cork nut
want grain want grain green woolgreen wool want a nutwant a nut
want corner want corner green birdiegreen birdie wanna cork nutwanna cork nut
wanna go-backwanna go-backbb go back go back wanna corn nutwanna corn nut
wanna come-here?wanna come-here?bb go chair go chair want some want some corn(er)corn(er)
wanna chair wanna chair here corn here corn 2-corner wood 2-corner wood
cork nut (an almond) cork nut (an almond) walnut grape walnut grape cork nut showercork nut shower
what’s here? what’s here? five corner five corner go back chairgo back chair
want ringwant ring do you wanna do you wanna grate?grate?
do you want grape?do you want grape?
you wanna go-back?you wanna go-back?bb
aa “Pa” is Griffin’s term for pasta. “Pa” is Griffin’s term for pasta. you wanna nut grapeyou wanna nut grape
bb “Come-here” and “go-back” seem to function as single units, i.e., unanalyzed wholes. “Come-here” and “go-back” seem to function as single units, i.e., unanalyzed wholes.
And splitting up the data like this
Doesn’t get into the ways that Greenfield examines children,
on the basis of phonemes
Dealing with “want cork” and “want corn” as three item
combinations
Issues of note:Issues of note:
Griffin was not trained on object-based tasksGriffin was not trained on object-based tasks
We looked for spontaneous manipulative behavior We looked for spontaneous manipulative behavior as vocalizations developed complexityas vocalizations developed complexity
He rarely combined >2 items, but percentages of He rarely combined >2 items, but percentages of 3-object and 3-label combinations were comparable3-object and 3-label combinations were comparable
We limited training on 3-label combinations; we We limited training on 3-label combinations; we then could document spontaneous utterancesthen could document spontaneous utterances
We trained “x-corner wood/paper”, but “2-corner We trained “x-corner wood/paper”, but “2-corner wood” was only 1/14 recorded 3-label combinations wood” was only 1/14 recorded 3-label combinations (i.e., labels Griffin chose to combine were rarely those (i.e., labels Griffin chose to combine were rarely those that he was taught)that he was taught)
Now, parrots don’t have a Broca’s area
Although new data suggest striking parallels between avian
and mammalian brains….
particularly with respect to areas involved in vocal
learning…
Researchers now think that the functions in mammalian Broca’s area are spread over more than
one avian area
And, of course, if you remember all the material on MNs, you begin to wonder about the
connection between MNs and these data
Other birds demonstrate related combinatorial behavior:
Male marsh wrens, Cistothorus palustris
engage in complicated woven nest building at the same time that they construct and memorize hierarchies of neighbors’ song repertoires so they can serially order their own song responses (i.e., reorder or recombine their own songs in new ways) to best defend their territories
Does the same neural substrate initially mediate concurrent vocal and physical combinatory behavior in any given avian species?
So….
Does a single substrate, if found, differ across avian species?
Neural structure of vocal control pathways differ between oscine songbirds and psittacids; the supposition has been that vocal learning arose independently in these groups…
but might the responsible structures may have been inherited from a common ancestor, and been lost in some descendants?
if one structure is indeed initially responsible for object-based and vocal combinations and
ThusThus….
even if this structure differentiates as an animal matures,
then psittacine and oscine combinatory behavior either
likely arose independently
or both evolved from a much earlier brain structure
in both wrens and parrots, physical and vocal combinations involve beaks and tongues;
Note, too….Note, too….
such data, along with arguments that spoken language derived from gestural/motor forms without major neural restructuring, add credence to a motor control theory of song origin (Nottebohm, 1991) and possible involvement of a related functional neural substrate