We investigated whether phonological deficits are a consequence of magnocellular processing deficits in dyslexic and control children. In Experiment 1, children were tested for reading ability, phonological awareness, visuo-magnocellular motion perception, and attention shifting (sometimes considered as magnocellular function). A two-step cluster analysis of the behavioural scores revealed four clusters of children. Phonological awareness was correlated with attention (cluster musical sharp1) or motion detection (cluster musical sharp2), whereas attention and motion detection were correlated in cluster musical sharp3. In cluster musical sharp4, all variables were uncorrelated. In Experiment 2, the same variables plus auditory discrimination were tested with fMRI in a sub-sample of Experiment 1. Although dyslexics had reduced activation in visual or auditory cortex during motion detection or auditory discrimination, respectively, they had increased right frontal activation in areas 44 and 45 in all 'magnocellular' (including auditory) tasks. In contrasts, during phonological decisions, there was higher activation for good readers than dyslexics in left areas 44 and 45. Together, the two experiments give insight into the interplay of phonological and magnocellular processing during reading. Distinct left versus right frontal effects reveal partly different underlying neural mechanisms. These data contradict the view that phonological processing deficits in dyslexia necessarily result from impaired magnocellular functioning.

Recent neuroimaging studies make contradictory predictions about the involvement of left Brodmann's area (BA) 44 in processing local syntactic violations in determiner phrases (DPs). Some studies suggest a role for BA 44 in detecting local syntactic violations, whereas others attribute this function to the left premotor cortex. Therefore, the present event-related functional magnetic resonance imaging (fMRI) study investigated whether left-cytoarchitectonic BA 44 was activated when German DPs involving syntactic gender violations were compared with correct DPs (correct: 'der Baum'-the[masculine] tree[masculine]; violated: 'das Baum'--the[neuter] tree[masculine]). Grammaticality judgements were made for both visual and auditory DPs to be able to generalize the results across modalities. Grammaticality judgements involved, among others, left BA 44 and left BA 6 in the premotor cortex for visual and auditory stimuli. Most importantly, activation in left BA 44 was consistently higher for violated than for correct DPs. This finding was behaviourally corroborated by longer reaction times for violated versus correct DPs. Additional brain regions, showing the same effect, included left premotor cortex, supplementary motor area, right middle and superior frontal cortex, and left cerebellum. Based on earlier findings from the literature, the results indicate the involvement of left BA 44 in processing local syntactic violations when these include morphological features, whereas left premotor cortex seems crucial for the detection of local word category violations.

Zusammenfassung Hintergrund: Im Rahmen von F?rderma?nahmen bei St?rungen des Leseerwerbs ist eine regelm??ige ?berpr?fung der individuellen Fortschritte unerl?sslich. Ziel der vorliegenden Studie war es, bez?glich aller wesentlichen linguistischen Faktoren parallelisierte Wortlisten f?r eine solche Verlaufsdiagnostik bereitzustellen. Gleichzeitig sollte durch die Auswahl des Wortmaterials eine ?berpr?fung der verschiedenen Lesestrategien und damit im Ansatz eine modellorientierte Diagnostik erm?glicht werden. Methode: Es wurden 4 parallelisierte Gesamtlisten erstellt, die sich jeweils aus verschiedenen Worttypen zusammensetzen. Zur ?berpr?fung ihrer Parallelit?t wurden die Listen zun?chst 28, nach Auswertung und ?berarbeitung nochmals 24 Drittkl?sslern zum Lesen vorgelegt. Die Parallelit?t sowohl der einzelnen Listentypen als auch der Gesamtlisten wurde hinsichtlich der Parameter Lesezeit, Fehleranzahl und Lesestrategie getestet. Ergebnisse: W?hrend die statistische Auswertung der 1. Version noch signifikante Unterschiede zwischen den 4 Gesamtlisten ergab, ist nach ?berarbeitung der Listen nun deren Einsatz als Paralleltests n?her ger?ckt. Die endg?ltige Best?tigung ihrer Parallelit?t anhand einer unabh?ngigen Stichprobe steht noch aus.