14 research outputs found
Left cytoarchitectonic BA 44 processes syntactic gender violations in determiner phrases
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
Entwicklung parallelisierter Wortlisten zur Verlaufsdiagnostik bei dyslektischen Kindern
Objective: In the course of the long-term treatment of developmental dyslexia it is important to continuously observe the progress of the individual reader. Considering the lack of reading tests with parallel forms which can be repeatedly administered without learning effects, and which are quick to perform, this is a big challenge in German-speaking regions. The aim of this study, therefore, was to create such an instrument in the form of several parallelised word lists. At the same time, the lists should allow a specific testing of both the lexical and the non-lexical route of reading, based on items with different linguistic properties.Method: 4 parallel lists were created, each composed of a wide range of different word material. To this end, word frequency, orthographic regularity, and morphological complexity were taken into account as linguistic criteria. To ensure that the lists were parallel with regard to the 3 parameters reading rate, accuracy and preferred reading strategy, they were presented to 28 third graders in a first test series. The lists were then revised and once again presented to 24 different children for final evaluation.Results: Whereas the statistical analysis of the first test series still differed with respect to the 3 above-mentioned parameters, in the revised version of the reading lists no more significant differences were found according to the linguistic criteria. As a consequence, as soon as an independent control sample has confirmed their parallelism, the lists will be ready for use for measuring the development of individual reading skills in dyslexic children
Distinct neural signatures of cognitive subtypes of dyslexia: Effects of lexicaliy during phonological processing
Rapid Automatized Naming, Verarbeitungs-geschwindigkeit und Leseflüssigkeit
A deficit in rapid automatized naming (RAN) is often associated with low performance in reading fluency, which is the core problem of German dyslectics. Furthermore, there is evidence that low naming speed might indicate inattention. This study therefore investigates the correlation of RAN with different measures of reading and attention in dyslectic children. The results show a correlation between RAN and reading fluency, reading comprehension and processing speed. Children whose naming speed is far below average show significantly lower values in reading fluency and comprehension as well as processing speed when compared to children of at least average RAN. This underlines the significance of low naming speed as an indicator for impaired reading fluency and comprehension. Beyond reading, reduced naming speed can point to a potential attention deficit
Training-induced brain activation changes in the frontal cortex differ in cognitive subtypes of dyslexia
Orientierungswerte für die Benennungsgeschwindigkeit bei leseunauffälligen Kindern im Alter von 9 bis 11 Jahren
Rapid automatised naming is a predictor of later reading achievement in transparent orthographies. For German, so far no standardised values for rapid naming in 3rd and 4th graders are available. The present study thus provided values for rapid naming performances for an adaptive version of the matrices “letters”, “numbers”, “colors” and “objects” (Mayer, 2008 [10]) on the basis of 53 typical 3rd and 4th graders (20 girls; mean age: 9.7 years (8.8–11.3 years; SD=0.54). Detailed analysis of the dataset showed that naming letters was significantly faster than naming other matrices and was strongly correlated with reading achievement
Should we train phonology, reading, or both? An intervention study with phonologically impaired dyslexic children.
Phonological processing in developmental dyslexics with and without phonological deficits.
Interaction of phonological awareness and magnocellular processing during normal and dyslexic reading: Behavioural and fMRI investigations.
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