Elkana, O., Frost, R., U., K., Hendler, T., Schmidt, D., & Schweiger, A. (2011).
Cerebral reorganization as a function of linguistic recovery in children: An FMRI investigation. Cortex ,
47 (2), 202-216.
Publisher's VersionAbstractCharacterizing and mapping the relationship between neuronal reorganization and functional recovery are essential to the understanding of cerebral plasticity and the dynamic processes which occur following brain damage. The neuronal mechanisms underlying linguistic recovery following left hemisphere (LH) lesions are still unknown. Using functional magnetic resonance imaging (fMRI), we investigated whether the extent of brain lateralization of linguistic functioning in specific regions of interest (ROIs) is correlated with the level of linguistic performance following recovery from acquired childhood aphasia. The study focused on a rare group of children in whom lesions occurred after normal language acquisition, but prior to complete maturation of the brain. During fMRI scanning, rhyming, comprehension and verb generation activation tasks were monitored. The imaging data were evaluated with reference to linguistic performance measured behaviorally during imaging, as well as outside the scanner. Compared with normal controls, we found greater right hemisphere (RH) lateralization in patients. However, correlations with linguistic performance showed that increased proficiency in linguistic tasks was associated with greater lateralization to the LH. These results were replicated in a longitudinal case study of a patient scanned twice, 3 years apart. Additional improvement in linguistic performance of the patient was accompanied by increasing lateralization to the LH in the anterior language region. This, however, was the result of a decreased involvement of the RH. These findings suggest that recovery is a dynamic, ongoing process, which may last for years after onset. The role of each hemisphere in the recovery process may continuously change within the chronic stage.
Bick, A. S., Goelman, G., & Frost, R. (2011).
Hebrew Brain vs. English Brain: Language Modulates the Way It Is Processed. Journal of Cognitive Neuroscience ,
23 (9), 2280 - 2290.
Publisher's VersionAbstractIs language processing universal? How do the specific properties of each language influence the way it is processed? In this study, we compare the neural correlates of morphological processing in Hebrew–a Semitic language with a rich and systematic morphology, to those revealed in English–an Indo-European language with a linear morphology. Using fMRI, we show that while in the bilingual brain both languages involve a common neural circuitry in processing morphological structure, this activation is significantly modulated by the different aspects of language. Whereas in Hebrew, morphological processing is independent of semantics, in English, morphological activation is clearly modulated by semantic overlap. These findings suggest that the processes involved in reading words are not universal, and therefore impose important constraints on current models of visual word recognition.
Frost, R. (2011).
Looking across orthographies. In
P. McCardle, R. Lee, J., J. L. Tzeng, O., & B. Miller (Ed.),
Dyslexia across languages: Ortography and the brain- gene- behavior Link. . Baltimor, Brookes Publishing Company.
Publisher's VersionAbstractWhat causes dyslexia, and how does it manifest across languages? As bilingualism becomes increasingly important globally, these questions have never been more critical–and this comprehensive volume from The Dyslexia Foundation explores them in unprecedented depth. Bringing together the best brain-based, genetics, and behavioral research in the field from more than 40 of today's most highly respected researchers, this landmark volume fully examines what we know about the identification, manifestations, and potential differences in dyslexia across languages and orthographies. International contributors share their groundbreaking studies, helping researchers and graduate-level students investigate key questions about dyslexia: (1) How does dyslexia vary in frequency and manifestation among speakers of various alphabetic and nonalphabetic languages?; (2) How might the characteristics of different languages affect reading acquisition and reading difficulties?; (3) How do genetic profiles
Velan, H., & Frost, R. (2011).
Words with and without internal structure: What determines the nature of orthographic and morphological processing? Cognition ,
118 (2), 141 - 156.
Publisher's VersionAbstractRecent studies suggest that basic effects which are markers of visual word recognition in Indo-European languages cannot be obtained in Hebrew or in Arabic. Although Hebrew has an alphabetic writing system, just like English, French, or Spanish, a series of studies consistently suggested that simple form-orthographic priming, or letter-transposition priming are not found in Hebrew. In four experiments, we tested the hypothesis that this is due to the fact that Semitic words have an underlying structure that constrains the possible alignment of phonemes and their respective letters. The experiments contrasted typical Semitic words which are root-derived, with Hebrew words of non-Semitic origin, which are morphologically simple and resemble base-words in European languages. Using RSVP, TL priming, and form-priming manipulations, we show that Hebrew readers process Hebrew words which are morphologically simple similar to the way they process English words. These words indeed reveal the t