From: Derek Bickerton <derek.bickerton@...
>On September 30th, Sergio Navega wrote
>>Could we think of another reason for the cognitive explosion *without*
>>massive changes in brain? Neanderthals are said to have similar, if
>>not slightly greater brain capacity.
>True, but according to one paleoanthropologist I talked to, possibly for an
>interesting reason--all the known Neanderthal skulls are those of males!
>Male brains tend to be larger than female (not because they're brainier,
>simply because male bodies tend to be bigger than female) so we don't have
>representative sample. But in any case, sheer size may not be the issue.
I didn't know about that. This could alter some of the traditional
>As evidenced in one of today's postings, people are beginning to find
>significant differences in the wiring patterns of human and primate brains.
>This is very exciting, but we need to bear in mind that we don't know at
>what stage in the evolution of humans these changes took place. Any or all
>of them could be relatively recent or four or five million years old, but
>money is on a lot of them originating with us. In other words,
>could have had brains that were organizationally closer to those of living
>primates than they were to ours.
I'm not so amazed to find out about differences in wiring patterns in
adult humans and primates. I would be considerably more perplex if these
different wiring patterns were found to exist in recently born babies
of both species. I guess we're often lead to find differences between
human and primate brains that, in fact, were essentially the result of
a different self-organization of the brains because of different
experiences of both organisms.
Brain plasticity appears to be largely driven by experience and
its effects are impressive (Dr. Skoyler's recent post about a new
paper in the Journal of Neuroscience adds to this idea).
>>Is it reasonable to suppose that
>>we have some kind of "neural exquisiteness", enough to jumpstart our
>>language and cognitive abilities?
>Perfectly reasonable. But alas, giving something a new name doesn't
>tell us anything, doesn't even rule out the possibiulity that "neural
>exquisiteness" could result from...well, massive changes in the brain!
>What has to be explained remains the same: humans are the only species,
>living or dead, to have shown "exponential growth".
I guess I had misconstructed my original question, leaving the
impression that I was suggesting the "exquisiteness", while in
fact I was saying that I *also* find it unlikely.
Just to redraw my thought again in better terms, I find it
unlikely that massive changes or any kind of deep neural
characteristic could have enough explanatory power to support
the origin of language in humans and not in other primates.
Although language in animals is still a highly debated issue,
one can't say that there isn't some sort of communication among
them. I wonder that this communication ability is due to a
comparable (albeit noticeably inferior) brain, capable of deriving
meanings from "symbolic" grunts and squeaks. They may lack the
sophisticated generative and recursive abilities that our
language has, but they certainly are able to pass simple
messages along. The bad part of this idea is that I don't have
much to support the conjecture, other than the huge similarity
in the neurobiological aspects of neurons among species.
>>I. find no convincing reason to
>>believe in that, in spite of the huge number of researchers who
>>find a place for "language organs" and "universal grammars" or
>>specialized neural circuitry. The idea of domain specificity, even
>>being accepted by the majority, is often put in doubt (Elman, Bates,
>A large part of the problem lies in confusion between domain specificty and
>localization. The two are often taken as going together, so once you've
>downed localization (as brain imaging has fairly well done for language
>functions) you've downed domain specificity, or as I'd rather call it,
>dedicated circuitry. No way. Once you grasp that the same cell or cell
>assembly may belong to several different circuits, the problem diminishes.
>Assume a brain of Dennettian dumb homunculi, with no executive suite,
>engaged in Darwinian competition for "spare" neurons a la Calvin, and it
Yes, I agree, often localization is taken to mean specificity. That
could be the case in adults, but I doubt that this can be seen in babies.
This is the question that puzzles me, the lack of studies in human
brain evolution from babyhood (I'd love to see more fMRI studies on
babies, but probably there are some serious - and justified - problems
with mommies). For what my opinion is worth, I believe that a lot
of doubts regarding language in humans would disappear once one
confirms the astonishing self-organizing abilities of a brain when
subjected to demanding interactive experiences. Children appear to
develop language in sort of a battle, struggling to understand and to
make their wishes understandable. It is not a fightless process.
This kind of "energy" usually drives adaptation and plasticity, as
studies with cortical rewiring in blind adults suggest.
By the way, Calvin's darwinian competition model are among my
preferred models. I closely follow all aspects related to this
issue such as information representation in population of
synchronously firing neurons. Calvin (and Gerald Edelman) will
be remembered for their important contribution to the field.
>>"Motherese", that special way of talking that mothers
>>exercise with their babies, is thought to be an essential
>>step in the development of a solid ground on which to plant
>>essential language constructs.
>Not by many acquisitionists. There are cultures in which motherese doesn't
>exist. And my own work on pidgins and creoles shows that children can
>languages that their mothers don't even know.
I agree, I again left the impression that I was proposing "motherese"
as a necessary condition, but this is just sufficient. Deaf children
can obviously learn language. What my point should have been is that
some kind of sensorimotor activity is necessary in order to support
language. This is obvious, but what is not so obvious is the way
in which this really supports cognition (the mechanics of it).
>.>I have a hunch that most
>>(if not all) of Chomsky's "poverty of stimulus" argument
>>could be seen upside down: it is not poverty, it is excess.
>Chomsky's arguments relate to linguistic, not extralinguistic input. No
>matter how rich either of them are, they have to be matched! See Judy
>Kegl's work on Nicaraguan sign language if you want to know how little
>linguistic input children can create a language from.
I agree that Chomsky's argument are essentially linguistic, and this
is what I see as the greatest problem with them. In my view, we can't
separate linguistic from extralinguistic inputs! Yes, sometimes we
may utter sentences that bear no direct relation to non-linguistic
aspects, such as "the man was convicted because he robbed". But this
sentence would not survive without the indirect associations to
our most primitive sensorimotor experiences that we have since
childhood. What I criticize in Chomskyan-like, purely syntactical
analysis is the unjustified dismissal of the constraints offered
by deep, non-linguistic structures. These structures are what could
be seen as providing the excess, not the poverty of stimulus.
I'll check for Judy's work but I expect to see more examples of
some sort of sensorimotor activity supporting language someway.
>>Now on a related question, Neanderthals apparently had similar
>>sensorimotor experiences, one of the proposed preconditions, but
>>did they had similar vocal tracts? Jared Diamond are among the
>>ones who see this as a meaningful clue.
>If their sensorimotor capacities were similar to ours, they should have
>able to develop a sign language (many language evolutionists believe that
>human language began with manual signs rather than speech, and there are
>good arguments for at least a mixed beginning). There is an abundance of
>evidence that the human language faculty is neutral wrt modality, so
>Neanderthal vocal difficulties aren't likely to be relevant here.
Ok, this one is really tough, I'm afraid I can't say much about. I
thank you for raising this, I certainly will benefit from thinking about
this aspect. Perhaps this is what was puzzling you from the beginning
and now I think I grasped your main point. You managed to transfer the
puzzlement to me!
In our search for a "guilty" for language evolution I guess we'll have
to conjecture wild things. It is noticeable that language is essentially
a social activity, an act that demands a speaker and a listener, at
least during the beginning of its evolution. This would suggest that
the organisms would have to care for each other, care for the group
or have a strong feeling of self-respect. Could that lead us to think
about the participation of emotions in this process? Could some sort
of emotional constructs be the missing link that hadn't a counterpart
in Neanderthals? Again, I'm asking more questions than proposing answers.
>After being rather critical, Sergio, let me at least congratulate you on
>being one of the few evol-psych contributors who regard the evolution of
>human intelligence as more than the differences between male and female
As a matter of fact, my main interest is a lot weirder than seeing
intelligence in men or women: I'm interested in intelligence in
machines. It is kind of baffling the history of AI with more than
4 decades of intense research and mild results. No real intelligence
has emerged. This is suspiciously similar to our case with
Neanderthals and Homo sapiens. Maybe solving the puzzle of one of
the mysteries will give us some hints on how to solve the other.
Anyway, thanks for the interesting dialogue.