Dear
Norbert,
I
hesitate to say ANYTHING in response to your last post because its positive
tone leaves me glowing, wonderful if everyone thinks the same about our
findings and our new work. But there are some foundational issues
where you and I diverge and they're worth a good vetting, I think.
I really was totally surprised at your equating
slow/probabilistic/associationistic learning with "learning in general,"
i.e. that if some change in an organism's internal state of knowledge wasn't
attributable to the action of this very mechanism, then it isn't learning at
all, but "something else." My own view of what makes
something learning is much more prosaic and excludes the identification of the
mechanism: if you come to know something via information acquired from
the outside, it's learning. So acquiring knowledge of Mickey
Mantle's batting average in 1950 or finding out that the pronunciation of the
concept 'dog' in English is "dog" both count as learning, to
me. At the opposite extreme of course are changes due entirely, so
far as we know, to internal forces, e.g., growing hair on your face or
replacing your down with feathers (though let's not quibble, some minimal external
conditions have to be met, even there). The in-between cases are
the ones to which Plato drew our attention, and maybe Noam is most responsible
in the modern era for reviving:
“But
if the knowledge which we acquired before birth was lost by us at birth, and afterwards
by the use of the senses we recovered that which we previously knew, will not
that which we call learning be a process of recovering our knowledge, and may
not this be rightly termed recollection?”
(Plato
Phaedo [ca. 412
BCE])
I take
UG to be a case, something (postulated) as an internal state, probably a
logically necessary one, that is implicit in the organism before knowledge
(say, information about English or Urdu) is obtained from the outside, and
which guides and helps organize acquisition of that language-specific
knowledge. I have always believed that most language acquisition is
consequent on and derivative from this structured, preprogrammed, basis, yet
something crucially comes from the outside and yields knowledge of English,
above and beyond the framework principles and functions of UG.
Syntactic bootstrapping, for example, is meant to be a theory describing how
knowledge of word meaning is acquired within (and "because of")
certain pre-existing representational principles, for example that -- globally
speaking -- "things" surface as NP's (further divided into the
animate and inanimate) and "events/states" as clauses, so the
structure NP gorps that S would be licensed for
"gorp" iff its semantics is to express a relation between a sentient
being and an event, e.g., "knowing" but not
"jumping."
The
problems we have in mind to address in the recent work you've been discussing,
to my delight, are: how do you ever discover where the NP's etc. are, in
English? That its subjects precede its verbs, roughly
speaking. This knowledge comes from outside (it is not true of all
languages) and has to be acquired to concretize the domain-specific procedure
in which you learn word meanings, in part at least, by examining the structures for
which they're licensed. I have argued that, at earliest stages, you can't make
contact with this preexisting knowledge just because you don't know, e.g. where
the subject of the sentence is. To find out, you have to learn a
few "seed words" via a domain-general procedure (available
across all the species of animals we know perhaps barring the paramecia)
. That procedure has almost always (since Hume, anyhow) been conceived as
association (in its technical sense). As I keep mentioning, success
in this procedure is vanishingly rare, it is horrible, because of the
complexity and variability of the external world, though reined in to some
extent by some (domain-specific) perceptual-conceptual biases (see Markman and
Wachtel, inter alia). Apparently, you can only acquire a pitiful set of
whole-object concrete concept labels by this technique. Though it
is so restrictive, we take it as crucial: it is the only possibility that
keeps "syntactic bootstrapping" from being absolutely circular, it
provides the enabling data for SB, enough nouns to hint as to where the subject
is, hence given this knowledge of "man" and "flower" and
the observation of a man watering a flower, you learn not only the verb
"water" but the fact that English is SVO.
So back
to the point: I think word learning starts with a domain-general
procedure that acquires "dog" by its cooccurrence with dog-sightings,
given innate knowledge of the concept ‘dog,’ and one learns (yes) that English
is SVO as a second step, and as above. This early procedure gives you
concretized PS representations, domain-specific, language-specific ones,
that allow you to infer "a verb with mental content" from appearance
in certain clausal environments. That's my story.
What my
argument with you, now, is about, is the contrapositive to Plato, I am asking:
"If you have to have information from the outside, information as to the
licensing conditions for "dog" (and, ultimately, "bark"),
is acquiring that information not rightly termed
learning?" I think it is. But the mechanism
turns out (if we're right) to be more like brute-force triggering than by
probabilistic compare-and-contrast across instances. The
exciting thing, as you mention, is that others through the last century (e.g.,
Rock, Bower, several others) insisted that learning in quite different
areas might work that way too. Most exciting I think is the work
starting in the 1940's and continued in the exquisite experimental work of
Randy Gallistel, showing that it is probably true of the wasps, the birds and
the bees, the rats, as well, even learning stupid things in the laboratory
(well, not Mickey Mantle's batting average, but, at least, where the food is
hidden in the maze).
