Path: utzoo!attcan!uunet!samsung!usc!ucsd!ucbvax!cogsci.berkeley.edu!edwards
From: edwards@cogsci.berkeley.edu (Jane Edwards)
Newsgroups: comp.ai
Subject: Re: Early Language Learning & Ancient Language
Summary: practical research strategy
Message-ID: <36581@ucbvax.BERKELEY.EDU>
Date: 28 May 90 22:15:29 GMT
References: <1990May25.142052.16989@athena.mit.edu> <7898@uhccux.uhcc.Hawaii.Edu> <1990May28.184332.25927@athena.mit.edu>
Sender: usenet@ucbvax.BERKELEY.EDU
Reply-To: edwards@cogsci.berkeley.edu (Jane Edwards)
Organization: University of California, Berkeley
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In article <1990May28.184332.25927@athena.mit.edu> ccimino@hstbme.mit.edu.UUCP (c cimino) writes:
>The comment about the difficulty of proving negative results is well taken.
>The example about cats raised in darkness illustrates that at least one 
>example exists to demonstrate the brain's non-plasticity, as much as people 
>would like to believe they can trancend their limits.

Ignoring for the moment the ideological stand, there is a purely practical
matter of which assumption is likely to generate the most careful scientific
inquiry.  Just because there may be developmental constraints on plasticity
in the visual system doesn't mean the same is true of other capabilities,
especially not those which are known to be more diffusely represented, i.e.,
less strictly regionalized.  (Note that speech recognition and production
involves more than just the mechanical speech centers.)  It seems almost 
mystical and far too easy scientifically to assume that just because there 
are some developmental constraints in one system there must necessarily be
the same kinds of constraints in others, especially when the domains and
tasks are so different.  Careful empirical work is needed, while keeping 
an open mind on what is to be found until the data are actually in.   

Concerning the differences in domains and tasks, a particularly important 
issue relevant to the r/l discussion, in my opinion, is the fact that the 
speech sounds which we categorize when listening to speech are not the 
same sounds from word to word nor from speaker to speaker, but rather involve
a constant re-calibration with reference to the context (e.g., word) in which 
they are embedded and the size and shape of the vocal tract of the person
producing them.  Pretty amazing process.  This process is not isomorphic
with such classification tasks as identifying vertical vs. horizontal lines, 
or other physically definable visual stimuli.  Adjustments and calibrations
are also needed in the latter, but without the necessity of engaging 
language understanding mechanisms relating to semantics, pragmatics, possible
alternatives in the lexicons, etc., i.e., aspects of processing which seem
likely to be more diffusely represented in the brain and hence not as
vulnerable to localized limits on plasticity.

The necessary research has not yet been done to substantiate the claims
one hears that adults are biological unable to acquire non-native phonologies,
so it seems to me important to keep the issue open to encourage the type of
rigorous research which is needed, namely the type which pushes language 
learners to their limits rather than assuming in advance that they are 
biologically incapable. This would involve such things as bombarding them 
with native speaker input (rather than the sizeable amount of non-native 
input they get from classmates in foreign language courses), under 
high-motivation circumstances (presumably using people who are not timid 
about leaving behind the hallmarks of their cultural identity 
while speaking the foreign language, or of feeling "silly" when making all
of these new sounds which are not yet habitual to them), and, finally,
monitoring separately their ability to *distinguish* the range of
variation associated with an r vs. an l (or whatever sounds are relevant),
from their ability to *produce* them in their own speech.  Until this
is done, it seems more practical in the long run in terms of progress in
our understanding to leave the issue open and avoid a stance of premature
biological determinism.

-Jane Edwards (edwards@cogsci.berkeley.edu)