Grammatical morphology in aphasia: evidence from three languages

Area of Science:

• Linguistics
• Neurolinguistics
• Psycholinguistics

Background:

• Investigating grammatical morphology in aphasia is crucial for understanding language processing deficits.
• The agrammatism/paragrammatism distinction is a key concept in aphasia research, but its cross-linguistic validity is debated.

Purpose of the Study:

• To examine grammatical morphology in Broca's and Wernicke's aphasia across different language groups (English, Italian, German).
• To assess the utility of the agrammatism/paragrammatism distinction in richly-inflected languages.
• To analyze language-specific patterns and error types in aphasic morphology.

Main Methods:

• Controlled elicitation of grammatical morphology in English, Italian, and German speakers with Broca's and Wernicke's aphasia.
• Quantitative analysis of morphology production, focusing on closed-class items and article usage.
• Qualitative error analysis to identify patterns and underlying mechanisms (e.g., access vs. loss).

Main Results:

• The agrammatism/paragrammatism distinction was less effective for richly-inflected languages like German and Italian.
• German and Italian patients produced significantly more morphology and used articles more frequently than English speakers.
• Article errors (substitutions) were non-random, indicating access difficulties rather than complete loss, particularly in German due to complex inflectional morphology.

Conclusions:

• The study challenges the universal applicability of the agrammatism/paragrammatism framework, especially in morphologically rich languages.
• Language-specific factors significantly influence morphological deficits and error patterns in aphasia.
• Broca's and Wernicke's aphasia exhibit distinct, though sometimes overlapping, error production strategies related to morphosyntactic complexity.