sensorimotor experience and language

[Brian MacWhinney]

Dear Jordan and Info-CHILDES,

The 1979 discussion of language in a paraplegic may have been
stimulated by the appearance in 1975 of an article by Fourcin in Eric
Lenneberg's "Foundations of Language Development. Vol 2" (pp. 263-268).
This article discusses the remarkable case of Richard Boydell, who was
anarthric and also quadraplegic.  His anarthria was extreme and he
could not produce language.   However, Boydell was quite bright and
appears to have had good use of his feet.  With his mother's help, he
learned to read and was able to communicate in beautiful English using
his feet and toes with a special typewriter.

At that time, this case was used as evidence against the motor theory
of speech perception.  However, it could perhaps also be used as
evidence against the sensorimotor account of language acquisition.
Jordan is perhaps specifically interested in how cases of this sort
might illuminate recent claims about embodied representations
underpinning language that arise from functional linguistics and parts
of psychology.

The case of Richard Boydell does not address these issues.  Boydell
apparently had good use of his feet.  I thought that quadraplegics were
paralyzed in both arms and both legs.  But this was evidently not the
case for Boydell.  In fact, the article discusses Boydell's "head and
body movements" and their use in communication at age 4.  Given this,
it is clear that Boydell had extensive access to sensorimotor mappings
of the type thought necessary to ground language.

So, we would need to be looking for a more extreme case than that
reported by Fourcin to understand the role of embodied representations.
My own guess is that the mapping between sensorimotor imagery and
language is important, but oblique in several ways.  In this regard, it
is useful to consider evidence for a double dissociation between visual
perception and visual imagery in agnosia from Behrmann and others.

--Brian MacWhinney