In this work, the acquisition of language by children with various developmental language disorders is compared with language acquisition by normal children.  The aims of this research are 1) to elucidate the nature of deficits underlying these disorders, and 2) to explore the extent to which language and subcomponents of language are modular.  Research on developmental speech dyspraxia suggests that the ability to comprehend language and make normal grammaticality
judgments does not depend on normal language production or negative evidence (Stromswold, 1994).
        As part of an ongoing study of language acquisition by children with Specific Language Impairment (SLI), we have studied the acquisition of case, tense and agreement (Stromswold & Sudhakar, 1997), overregularization (Stromswold, Sudhakar, & Connolly, in preparation), questions and auxiliaries (Stromswold, Sudhakar, & Nappa, in preparation), and phonology (Stromswold & Rifkin, 1996; Stromswold, Arnold, & Rauf, 1998).  This research suggests that, although SLI children acquire language more slowly and make more errors than normal children, SLI children go through the same stages of acquisition and make the same types of errors as normal children, suggesting that their language is delayed rather than deviant.  In related research, we are investigating the syntactic, phonological, and linguistic tradeoffs that children make (Stromswold, Arnold, & Rauf, 1998). We have found that, for both normal and SLI children, increased performance loads in one subcomponent of language (e.g., phonology) lead to decreased performance in that area and other areas of language (e.g., morphosyntax, lexicon).  This suggests that children have a single (limited) pool of performance resources that they can devote to language tasks, be they phonological, syntactic or lexical and that, at the performance level, the various subcomponents of language are not insulated from one another.

Relevant Papers

Stromswold, K., 1994.  Language comprehension without language production:  Implications for
theories of language acquisition. Paper presented at the 18th Annual Boston University
Conference on Language Development.  January 1994.

Stromswold, K.  1995b. The cognitive and neural bases of language acquisition.  M. Gazzaniga
(ed.), The cognitive neurosciences, pp 855-870.  Cambridge, MA:  MIT Press.

Stromswold, K.  1997.  Specific language impairments.  T. Feinberg and M. Farah, eds.,
Behavioral  neurology and  neuropsychology, pp. 755-772.  New York:  McGraw Hill
.
Stromswold, K.  1999b. The cognitive neuroscience of language acquisition.  M. Gazzaniga (ed.),  The cognitive neurosciences, second edition.  pp 909-932.  Cambridge, MA:  MIT Press.

Stromswold, K., Rauf, L., and Arnold, K.  1998. Phonological and syntactic trade offs in acquisition.  (Paper accepted at the 23rd Annual Boston University Conference on Language Development, but not presented because of illness.)

Stromswold, K.  & Sudhakar, M.  1998.  A longitudinal study of pronoun acquisition by SLI
children.  Paper presented at the Symposium on Research in Child Language Disorders.  June, 1998

Stromswold, K. & Rifkin, J.  1996.  Language acquisition by identical versus fraternal SLI twins.  Paper presented at the Symposium on Research in Child Language Disorders.  June,  1996