Rule-based learning of regular past tense in children with specific language impairment

Abstract

The treatment of children with specific language impairment was used as a means to investigate whether a single- or dual-mechanism theory best conceptualizes the acquisition of English past tense. The dual-mechanism theory proposes that regular English past-tense forms are produced via a rule-based process whereas past-tense forms of irregular verbs are stored in the lexicon. Single-mechanism theories propose that both regular and irregular past-tense verbs are stored in the lexicon. Five 5-year-olds with specific language impairment received treatment for regular past tense. The children were tested on regular past-tense production and third-person singular “s” twice before treatment and once after treatment, at eight-week intervals. Treatment consisted of one-hour play-based sessions, once weekly, for eight weeks. Crucially, treatment focused on different lexical items from those in the test. Each child demonstrated significant improvement on the untreated past-tense test items after treatment, but no improvement on the untreated third-person singular “s”. Generalization to untreated past-tense verbs could not be attributed to a frequency effect or to phonological similarity of trained and tested items. It is argued that the results are consistent with a dual-mechanism theory of past-tense inflection.

Keywords:

• past tense
• treatment
• intervention
• specific language impairment
• dual-mechanism theory
• single-mechanism theory
• rule-based
• connectionist
• specific language impairment

Acknowledgements

This work would not have been possible without the participation of the children, parents, and the generous and dedicated staff of the Fremantle and West Coast Language Development Centres in Perth, Western Australia.

Disclosure statement

The author has no financial interest or benefit from the direct application of this research.

Additional information

Funding

This study was funded by the Australian Research Council Centre of Excellence in Cognition and its Disorders [grant number CE110001021] (http://www.ccd.edu.au).