LINGUIST List 8.1476

Sun Oct 12 1997

Sum: Language Locations in the Brain

Editor for this issue: Martin Jacobsen <martylinguistlist.org>


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  1. George Elgin, Suzette Haden Elgin, Summary: language "locations" in the bilingual brain

Message 1: Summary: language "locations" in the bilingual brain

Date: Sun, 12 Oct 1997 14:38:26 -0500
From: George Elgin, Suzette Haden Elgin <oclsipa.net>
Subject: Summary: language "locations" in the bilingual brain

Recently I posted a request on this list (and several others) for
reactions to the 7/10/97 article by Kim and Hirsch in *Nature*
reporting functional MRI research showing a difference between
bilinguals acquiring both languages as infants or young children, and
bilinguals acquiring their second language as adults. A Memorial
Sloan-Kettering news release had the following quotation attributed to
Dr. Joy Hirsch: "A second language acquired during the teenage years,
which is late in developmental life, is represented in the brain in a
separate location from the native language. But when both languages
are learned at the same time early in life, they are represented in
areas that have a considerable amount of overlap." ("Bilinguals
Devote Distinct Areas of Brain to Native and Second Languages," MSKCC:
Press Releases, online.) The NY Times for 7/15/97 ran a story titled
"When an Adult Adds a Language, It's One Brain, Two Systems"; the Wall
Street Journal's story on 7/10/97 had two headlines -- "How Language
Is Stored in Brain Depends on Age" and "Where Languages Are Stored in
Brain Depends on Your Age." I immediately began receiving phone calls
and mail with questions about this research. I am not a neuroscientist
and did not feel competent to answer the questions with even minimal
accuracy; I am very unwilling to add to the usual confusion created by
such media reports. I wrote the authors requesting clarification, and
got no response; I did an online search and found nothing that I felt
I could trust; I then asked for help from the lists. (Depending on the
precise wording, a search on "language locations in the brain in
bilinguals/multilinguals" on Neuroscience Web Search gets roughly 3000
hits, through which I have been doggedly working my way.) My sincere
thanks to all who responded.

The majority of responses were from individuals expressing interest
and asking that I share whatever information came my way. A number of
responses can be summarized as "This research is nothing new, nor is
it especially significant." (Medical professionals responding, who
rely on information of this kind in order to do neurosurgery without
catastrophic effects on language capacity in patients, disagreed with
that judgment.) A number of bilingual or monolingual responders wrote
with accounts of personal experiences that were extremely useful and
interesting. Excerpts from responses that strike me as of general
interest follow; they are taken from very lengthy postings and should
be understood *only* as excerpts.

 From Joe Hilferty: "Kim et al. ...just investigated neural
activation in Wernicke's and Broca's areas, because the two sites are
well known from the long tradition of aphasia studies. Their findings
do not mean, however, that language is only processed in these areas
of the brain." References suggested: ** Bates 1994, "Modularity,
Domain Specificity and the Development of Language," Discussions in
Neuroscience 10:1-2;136-149. **Maratsos and Matheny 1994, "Language
Specificity and Elasticity," Annual Review of Psychology 45: 487-516.

 From Brian MacWhinney: "I have argued that early bilinguals
project the input linguistic data to a single space, because that
space is not yet saturated by weights on synaptic connections and the
two systems can be learned together in a computationally reasonable
sense without worrying about catastrophic interference. In adult L2
learning, the optimal area for an ability has already been occupied
and new learning must either use the old territory in a new way or
else coopt adjacent 'new' territory. ... A lot of what is at issue
here is exactly what the role of Broca's area in language processing
might be. ... I would like to think of Broca's as controlling high
level sequential planning for language and related abilities."

 From Liz Bates: "I believe that the article in Nature on differential
localization for Language 1 and Language 2 represents the kind of
gross over-interpretation of neural imaging data that has become all
too common in the last few years. Let's be clear about exactly what
this paper (like many others before it -- this is not the first paper
on neural imaging in bilinguals) has really shown: (1) patterns of
activation associated with covert speech in L1 and L2 are largely very
similar, but (2) there are some reliable differences in the center and
extent of activation in the Broca region. None of this has anything
necessarily to do with STORAGE of L1 vs. L2! ...

Aside from this serious problem of confusing patterns of slightly
non-overlapping activity with separate modules, separate mechanisms,
separate storage of knowledge, there are other problems here as well.
For example, the assumption that Broca's area mediates grammar while
Wernicke's area mediates semantics is HIGHLY controversial, and in my
view, probably dead wrong. Both Broca's and Wernicke's aphasics have
severe grammatical problems, but they take a somewhat different form
(e.g. omission in the former case, substitution in the latter). And
those studies that have tried to find a 'grammar area' through neural
imaging of normals have generally found EITHER that grammar and
lexical semantics activate the same areas, OR they have found
differences that vary markedly from study to study, and even from one
individual patient to another -- consistent with a "task demand"
interpretation of the data. Another problem lies in the assumption
that any area which mediates language is a "language area." In fact,
a number of recent neural imaging studies have shown that EVERY SINGLE
PIECE of the Broca's area complex (and, by the way, even the
boundaries of Broca's area of controversial, varying from study to
study) is activated by one or more covert motor tasks involving
non-linguistic motor activities, of the hands or tongue or both. So
it is possible that ALL we are seeing in this study in Nature is an
effect in which bilinguals set their mouths a little differently
(covertly, of course) while speaking their second language -- possibly
reflecting greater difficulty in L2 in this case."

>From Lise Menn: "It's not an unreasonable result given earlier
indications that late bilinguals had a more bilateral representation
of language than early bilinguals (using one-hand motor tasks as
indicators of hemispheric involvement), and given Damasio's claims
that meaning of words with concrete referents is represented in a way
that is linked to our sensory expereince of those referents (hence,
language independent).

Additional references that were suggested to me by a number of list
members:

Hull, Philip, 1990. UC Berkeley Psych. Dept. dissertation. 
"Bilingualism: Two languages, two personalities."

Bain, Bruce, 1996. Pathways to the peak of Mount Piaget and Vygotsky:
Speaking and cognizing monolingually and bilingually. Rome: Bulzoni
Editore.

Mollica, Anthony and Marcel Danesi, 1995. "The Foray into the
Neurosciences: Have We Learned Anything Useful Yet?" Mosaic 2:4;12-20.

Danesi, Marcel, 1994. "The Neuroscientific Perspective in Second
Language Acquisition Research: A Critical Synopsis. International
Review of Applied Linguistics 32:3;201-228.

In addition to my desire not to answer questions about this matter
stupidly and/or ignorantly, I was interested in this research because
I have been investigating the perception in many
bilinguals/multilinguals that they are "a different person" when they
use different languages. (I won't bore you with an account of this; I
mention it just to provide context.) I became interested in this when
Diana Cook sent me "The Bilingual Self: Duet in Two Voices," by
RoseMarie Perez Foster, "Cultural and Conceptual Dissonance in
Theoretical Practice," by Carla Massey (a response to the previous
item), and "The Bilingual Self--Thoughts from a Scientific Positivist
or Pragmatic Psychoanalyst, by Perez Foster (a reply to Massey). All
are from Psychoanalysitc Dialogues 6:1, 1996, pp. 99 ff. (Sample from
Perez Foster's article, page 101: "Thus the bilingual person presents
a packaging puzzle, as it were, in which two language-bounded
experiential systems are housed in the confines of a single mind." And
from page 100, "Bilinguals may possess different experiences of the
self, which are organized around their respective languages.") It
would have been extremely interesting if the individuals in my
database who report this "different person" perception and those who
do not correlated in some fashion with the "different storage
locations in the brain" research; they do not.

I found especially helpful, and thorough, and informative, the article
"Brain evolution and neurolinguistic preconditions," by Wendy
K. Wilkins and Jennie Wakefield, in Behavioral and Brain Sciences
(1995) 18:161-226, together with the many pages of commentary on their
target article in the same and subsequent issues and their responses
to those comments. Wilkins and Wakefield (page 170) propose that
Broca's area is "a processing module whose inherent specialization is
the hierarchical structuring of information in a format consistent
with a temporally ordered linear sequence reflective of that
structure."

Suzette Haden Elgin
oclsipa.net
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