Regular and irregular inflection in down syndrome - New evidence from German

Area of Science:

• Linguistics
• Developmental Psychology
• Neuroscience

Background:

• Inflectional morphology is crucial for grammatical accuracy.
• Down syndrome (DS) can impact cognitive and linguistic development.
• Understanding specific linguistic challenges in DS is vital for targeted interventions.

Purpose of the Study:

• To investigate the acquisition of regular inflectional morphology in German children and adolescents with Down syndrome (DS).
• To determine if DS affects the ability to use regular inflectional markers, specifically the past participle -t.
• To explore the potential for selective deficits in regular inflectional processing within the DS population.

Main Methods:

• Elicitation of German past participle forms for regular, irregular, and novel verbs.
• Comparison between 21 children/adolescents with DS and 21 typically developing children matched for nonverbal mental age.
• Analysis of the acquisition and application of the regular participle marker -t.

Main Results:

• Eight individuals with DS showed a deficit in acquiring and applying the regular participle marker -t.
• Thirteen individuals with DS performed similarly to controls, successfully acquiring and applying the -t affix.
• A substantial number of individuals with DS displayed a selective deficit in regular default inflection.

Conclusions:

• Acquisition of regular inflectional morphology is achievable for many individuals with DS.
• A significant subset of individuals with DS exhibits a selective deficit in regular default inflection.
• Findings support dualistic models of inflection, suggesting separate cognitive components for regular and irregular morphology that can be differentially impaired.