An area essential for linking word meanings to word forms: evidence from primary progressive aphasia.

We investigated the relationship between deficits in naming and areas of focal atrophy in primary progressive aphasia (a neurodegenerative disease that specifically affects language processing). We tested patients, across multiple input modalities, on traditional naming tasks (picture naming) and more complex tasks (sentence completion with a name, naming in response to a question) and obtained high resolution MRI. Across most tasks, error rates were correlated with atrophy in the left middle and posterior inferior temporal gyrus. Overall, this result converges with prior literature suggesting that this region plays a major role in modality independent lexical processing.

Expressive and receptive vocabulary in children with Williams and Down syndromes.

BACKGROUND: Williams (WS) and Down syndromes (DS) are two genetic disorders that involve intellectual disability (ID) and have been extensively studied over the past decades because of the unique linguistic profiles they exhibit. Recent investigations seek to explore the fractionation of linguistic components within the cognitive system using genetically based neurodevelopmental disorders such as WS and DS and to identify different profiles of linguistic function in these two groups of individuals. METHOD: The 'expressive vocabulary', 'receptive vocabulary', 'word opposites' and 'word definitions' subtests (Level 1) of the Test of Word Knowledge (TOWK) were used to assess lexical skills in six children with WS and five children with DS. RESULTS: Our findings indicate that the two syndromes exhibit substantial differences on linguistic tasks with individuals with WS performing at a higher level compared to those with DS and producing atypical responses in word definitions. The pattern of errors for each syndrome is qualitatively different suggesting that their underlying linguistic mechanisms are distinctive even though ID is similar. CONCLUSIONS: This study supports the differential outcome of two chromosomal disorders with similar ID. It also argues in favour of the large within group variability of the two syndromes that is not related to mental age but rather to different underlying mechanisms supporting language. These findings are discussed in the light of the current evidence concerning linguistic knowledge of neurodevelopmental and genetic disorders.

Does phonological change play a role in the recognition of derived forms across modalities?

This study investigates the way in which phonological change during derivation influences the access of complex words in the on-line performance of English-speaking subjects during word recognition. Three visual lexical decision experiments were administered (cross-modal priming, visual priming and simple). Overall, the results showed that the forms which were subject to phonological change during derivation were always recognized significantly slower than those without phonological alterations. The results confirm the role of phonological change in accessing derived words. They also have important implications for a theory of lexical representation.

Processing compounds: A cross-linguistic study.

This study explores the role of semantic transparency and morphological headedness in the on-line visual recognition of French and Bulgarian compounds using a constituent repetition priming paradigm. The results reported show significant constituent priming effects for both languages. Moreover, distinct priming patterns emerged, demonstrating that the semantic transparency of individual constituents, their position in the string, and morphological headedness interact in the processing of compounds.

The role of morphological structure in the processing of compounds: the interface between linguistics and psycholinguistics.

This study presents a cross-linguistic investigation of lexical access and subjects' sensitivity to the internal morphological structure of compounds in two highly inflected languages, Greek and Polish. The following questions were addressed: Are individual constituents activated during on-line word recognition? To what extent does internal morphological structure play a role during lexical access? Is there an interaction between headedness and constituent-priming given that the inflection that the second constituent carries determines the gender, number, and case of the compound? Our results show activation of individual constituents of compounds during priming, a strong word effect, and a positional advantage for first constituents in spite of the presence of second constituent heads.