Specific language impairment and grammatical morphology: a discriminant function analysis

Area of Science:

• Linguistics
• Developmental Psychology
• Speech-Language Pathology

Background:

• Specific language impairment (SLI) affects grammatical morpheme production in preschool children.
• Accurate classification of SLI is crucial for timely intervention.
• Existing diagnostic tools may benefit from refined linguistic markers.

Purpose of the Study:

• To determine if grammatical morpheme production can classify preschool children with SLI.
• To evaluate the diagnostic utility of specific morpheme composites and mean length of utterance (MLU).
• To identify potential clinical markers for SLI.

Main Methods:

• Discriminant function analysis was used to classify children.
• Three variables were analyzed: finite verb morpheme composite, noun morpheme composite, and MLU in morphemes.
• The study included preschool-age children with SLI and typically developing controls across two samples.

Main Results:

• Discriminant analysis achieved high accuracy in distinguishing children with SLI from controls.
• The verb morpheme composite demonstrated high sensitivity (>85%) and perfect specificity (100%).
• Classification accuracy varied slightly across the three variables.

Conclusions:

• Grammatical morpheme production, particularly verb morphology, is a promising indicator for classifying SLI in preschoolers.
• The verb morpheme composite shows potential as a reliable clinical marker for SLI.
• These findings support the continued relevance of verb morphology deficits in SLI into school-age years.