Background: The most common cause of aphasia is a left middle cerebral artery stroke affecting the left perisylvian region of the brain. The perisylvian region is critical for supporting phonological processing, and damage to this region results in difficulty with retrieving and manipulating speech sounds. The impact of weakened phonology has been…

Primary progressive aphasia (PPA) is an acquired neurodegenerative syndrome that has specific and devastating effects on an individual's speech and language ability. Based on a detailed assessment of behavior and cognition, combined with structural neuroimaging data and pathological evidence, PPA is typically classified into three variants: the…

This dissertation is an analysis of two types of nominal compounds in Turkish, primary compounds and synthetic compounds within the framework of Distributed Morphology. A nominal primary compound is formed by two nouns, and its meaning is largely determined by world knowledge. A synthetic compound, on the other hand, is formed by a noun and a…

Producing a sentence involves encoding a preverbal message into a grammatical structure by retrieving lexical items and integrating them into a functional (semantic-to-grammatical) structure. Individuals with agrammatism are impaired in this grammatical encoding process. However, it is unclear what aspect of grammatical encoding is impaired and…

Failure to supply inflection is common in adult L2 learners of English and agrammatic aphasics (AAs), who are known to resort to bare verb forms. Among attempts to explain the absence of inflection are competing morphological and phonological explanations. In the L2 acquisition literature, omission of inflection is explained in terms of: mapping…

Agrammatism is a frequent sequela of Broca's aphasia that manifests itself in omission and/or substitution of the grammatical morphemes in spontaneous and constrained speech. The hierarchical structure of syntactic trees has been proposed as an account for difficulty across grammatical morphemes (e.g., tense, agreement, and negation). Supporting…