infant "sign"

[Adele Abrahamsen]

On Sat, 8 Jan 2005, Professor Annette Karmiloff-Smith wrote:

> I have been asked to find out what serious sceintific studies have
> been done on the effects of teaching hearing infants to use "signs"
> (I am not talking about the real language, ASL or BSL, but a list of
> lexical signs taught to "advance infant communication skills" before
> they are able to vocalise).
>
Hi, Annette, your inquirer might want to look at a 2000 book
chapter in which I sought to integrate findings from studies
involving three variations on bimodal input, especially:
1.  Acredolo and Goodwyn's invented symbolic gestures (baby
signs);
2.  my own enhanced gestural input, in which signs borrowed
from ASL accompany some of the words in the speech stream;
3.  ASL, based on studies by Folven and Bonvillian (not
the situation you asked about, but it provides an informative
comparison).
I will use the term "symbolic gestures" for manual
or bodily gestures or signs from a conventional signed
language (such as ASL) that meet criteria of referential use.
(References are at the end of this message)

One point I emphasized in the chapter is that symbolic
gestures and words are indistinguishable on some key measures,
such as mean age (and even standard deviation) of first and
fifth symbol.  Typically the first 5 to 15 or more symbols
include gestures for some meanings and words for others.
There are large individual differences -- some children have
more gestures, others more words, others balanced -- but most
important is that they are using both.

Thus, symbolic gestures are not so much an early, preverbal
SUBSTITUTE for words as an ADDITIONAL RESOURCE for children
who are also communicating vocally.  Enhancing the amount and
diversity of gestural input enables a larger total vocabulary
of gestures and words through 1 1/2 years or so.  This is
consistent with the idea that early symbolic and communicative
development is bimodal, as emphasized since the 1970s by M. A.
Halliday, Elizabeth Bates, Virginia Volterra, and others. I
have observed the two modalities become increasingly
coordinated after the earliest months (e.g., more overlap in
vocabulary and simultaneous production), but then interest
in symbolic gestures declines as speech accelerates. (Changes
like this have been reported for nonsymbolic gestures such
as pointing as well.)

Another point that emerged from comparing these studies is
that below 1 1/2 years or so, the amount and kind of
gesture/sign input makes surprisingly little difference to the
size of expressive vocabulary.  Children immersed in ASL from
birth do acquire more by 1 1/2 years than children getting
enhanced input, which typically involves mere dozens of extra
(gestural)  symbols beginning around 11 months. However,
despite this greatly disproportionate input in the manual
modality, median vocabulary size in that modality differs only
by a factor of about 2. I call this period of relatively slow
growth, equipotentiality of modalities, and relative
insensitivity to amount of input the "bimodal period." Much
changes as it is left behind, a story told well by others but
beyond the scope of the studies referenced below.

> I'd appreciate refs, abstracts of refs, of scientific studies, as
> well as any personal experiences.
> Rather urgent please.
> Many thanks, and HAPPY NEW YEAR TO ALL,
> Annette K-S
>
I am indebted to Linda Acredolo and John Bonvillian not only
for their important published work but also for supplying me
with more detailed data from their studies.  Anyone seriously
interested in the topic should, of course, not rely on my
brief comments here but consult each research team's original
reports.  They would not necessarily agree with everything I
have said or with where I have placed emphasis. Much more
detail about my methods for comparing the studies and
additional conclusions are in the Abrahamsen (2000) chapter.

I am also happy to address specific questions posed for
which I have relevant data or experiences.


REFERENCES

Acredolo and Goodwyn -- References already sent by Diane
Pesco and Margaret Friend in response to your inquiry;
not repeated here.

Abrahamsen, A. (2000). Explorations of enhanced gestural input
to children in the bimodal period. In K. Emmorey and H. Lane
(Eds.), The signs of language revisited: An anthology to honor
Ursula Bellugi and Edward Klima (pp. 357-399). Hillsdale, NJ:
Erlbaum.

Abrahamsen, A. A., Lamb, M., Brown-Williams, J., & McCarthy,
S. (1991). Boundary conditions on language emergence:
Contributions from atypical learners and input. In P. Siple &
S. Fischer (Eds.), Theoretical issues in sign language
research. Volume 2: Psychology (pp. 231-254). Chicago:
University of Chicago Press.

Abrahamsen, A. A., Cavallo, M. M., & McCluer, J. A. (1985). Is
the sign advantage a robust phenomenon? From gesture to
language in two modalities. Merrill-Palmer Quarterly, 31,
177-209. [answer: no]

Bonvillian, J. (1999), Sign language development.
In M. Barrett (Ed.), The development of language.
Studies in developmental psychology (pp. 277-310).
New York: Psychology Press.

Folven, R. J., and Bonvillian, J. D.
(1993).  Sign language acquisition: Developmental aspects.
In M. Marschark and M. D. Clark (Eds.).
Psychological perspectives on deafness (pp. 229-265).
Hillsdale, NJ: Erlbaum.

Folven, R. J., and Bonvillian, J. D. (1991).
The transition from nonreferential to referential language in
children acquiring American Sign Language. Developmental
Psychology. Vol 27(5), 806-816.


--
Dr. Adele Abrahamsen
Center for Research in Language
University of California, San Diego
9500 Gilman Drive, 0526
La Jolla, CA 92093-0526

Office telephone: 858-822-1941
Office location:  7023 HSS

Email:  adele at crl.ucsd.edu

Homepage:  mechanism.ucsd.edu/~adele
Inquiry website:  inquiry.ucsd.edu