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Ria De Bleser

Publications and source records attributed to Ria De Bleser.

9 recordsLinked to original sources
PubMed2007

Late acquisition of literacy in a native language.

With event-related functional MRI (fMRI) and with behavioral measures we studied the brain processes underlying the acquisition of native language literacy. Adult dialect speakers were scanned while reading words belonging to three different conditions: dialect words, i.e., the native language in which subjects are illiterate (dialect), German words, i.e., the second language in which subjects are literate, and pseudo-words. Investigating literacy acquisition of a dialect may reveal how novel readers of a language build an orthographic lexicon, i.e., establish a link between already available semantic and phonological representations and new orthographic word forms. The main results of the study indicate that a set of regions, including the left anterior hippocampal formation and subcortical nuclei, is involved in the buildup of orthographic representations. The repeated exposure to written dialect words resulted in a convergence of the neural substrate to that of the language in which these subjects were already proficient readers. The latter result is compatible with a "fast" brain plasticity process that may be related to a shift of reading strategies.

Adult↗
PubMed2006

Determining language laterality by fMRI and dichotic listening.

For imaging studies on hemispheric specialization of the human brain, data about known functional asymmetries other than handedness would be valuable for a reliable interpretation of lateralized activation in individuals or groups of subjects. As certain aspects of language processing are observed to be a function of primarily the left, it can be used as a reference for other asymmetric processes such as sensory or cognitive skills. For analyzing language laterality, there are a variety of methods, but these differ in application or accuracy. In this study, we tested the reliability of two widely used methods - dichotic listening and fMRI - to determine language dominance in 30 individual subjects. The German adaptation of a dichotic listening test (Hättig, H., Beier, M., 2000. FRWT: a dichotic listening test for clinical and scientific contexts, Zeitschr f Neuropsychologie 11. 233-245.) classified 54% of the 26 right-handed subjects as left hemispheric dominant. The results of the fMRI paradigm (Fernández, G., de Greiff, A., von Oertzen, J., et al., 2001. Language mapping in less than 15 min: real-time functional MRI during routine clinical investigation. Neuroimage 14, 585-594.) tested on the same subjects, however, classified 92% of the right-handed subjects as left dominant. The main reason for this discrepancy was that the ear dominance score of many subjects in the dichotic listening test was too low to determine a reliable ear advantage. As a consequence, this specific dichotic listening test cannot be used to determine language laterality in individual subjects. On the other hand, the fMRI results are consistent with numerous studies showing left dominant language processing in more than 90% of right-handers. In some subjects, however, language laterality critically depends on the areas used to determine the laterality index.

Acoustic Stimulation↗
PubMed2006

A linguist's views on progressive anomia: evidence for Delbrück (1886) in modern neurolinguistic research.

In his short paper of 1886, the neogrammarian linguist Delbrück sketches his views on normal language processing and their relevance for the interpretation of some of the symptoms of progressive anomic aphasia. In particular, he discusses proper name impairments, verb and abstract noun superiority and the predominance of semantically related errors. Furthermore, he suggests that part of speech, morphology and word order may be preserved in this condition. This historical document has been lost in oblivion but the original ideas and their relevance for contemporary discussions merit a revival.

Anomia↗
PubMed2005

Tense and Agreement dissociations in German agrammatic speakers: underspecification vs. hierarchy.

The aim of the present paper was to investigate whether German agrammatic production data are compatible with the Tree-Pruning-Hypothesis (TPH; Friedmann & Grodzinsky, 1997). The theory predicts unidirectional patterns of dissociation in agrammatic production data with respect to Tense and Agreement. However, there was evidence of a double dissociation between Tense and Agreement in our data. The presence of a bidirectional dissociation is incompatible with any theory which assumes a hierarchical order between these categories such as the TPH or other versions thereof (such as Lee's, 2003 top--down hypothesis). It will be argued that the data can better be accounted for by relying on newer linguistic theories such as the Minimalist Program (MP,), which does not assume a hierarchical order between independent syntactic Tense and Agreement nodes but treats them as different features (semantically interpretable vs. uninterpretable) under a single node.

Acoustic Stimulation↗
PubMed2004

Neural correlates of syntactic transformations.

Many agrammatic aphasics have a specific syntactic comprehension deficit involving processing syntactic transformations. It has been proposed that this deficit is due to a dysfunction of Broca's area, an area that is thought to be critical for comprehension of complex transformed sentences. The goal of this study was to investigate the role of Broca's area in processing canonical and non-canonical sentences in healthy subjects. The sentences were presented auditorily and were controlled for task difficulty. Subjects were asked to judge the grammaticality of the sentences while their brain activity was monitored using event-related functional magnetic resonance imaging. Processing both kinds of sentences resulted in activation of language-related brain regions. Comparison of non-canonical and canonical sentences showed greater activation in bilateral temporal regions; a greater activation of Broca's area in processing antecedent-gap relations was not found. Moreover, the posterior part of Broca's area was conjointly activated by both sentence conditions. Broca's area is thus involved in general syntactic processing as required by grammaticality judgments and does not seem to have a specific role in processing syntactic transformations.

Adult↗
PubMed2003

Does morphology make the difference? Agrammatic sentence comprehension in German.

This study examines the syntactic comprehension of seven German agrammatic speakers. The German language allows the study of the interaction of syntactic principles and morphological devices in the comprehension process. In addition, due to its relatively free word order, German allows the study of strictly minimal pairs of canonical and non-canonical sentences in addition to the rather controversial active-passive contrast. A central research question was whether the pattern of agrammatic comprehension predicted by the trace deletion hypothesis (TDH, Grodzinsky, 1990, 1995), relatively normal comprehension performance of canonical sentences and chance performance on non-canonical sentences, can be found in a language with richer morphology than English. The generalisability of the TDH-pattern to morphologically rich languages is not obvious, given that case morphology in particular can provide explicit cues to the detection of the agent and patient roles in a sentence. The results of this study indicate that morphology does not make a difference. Furthermore, the group results are in line with the TDH-predictions only for number marked sentences but not for case marked sentences. However, single case analysis reveals different patterns of syntactic comprehension in agrammatic patients, a spectrum that encompasses near-normal comprehension of canonical and non-canonical sentences, overall chance performance, and TDH-like profiles.

Adult↗
PubMed2003

A cross-linguistic data bank for oral picture naming in Dutch, English, German, French, Italian, Russian, Spanish, and Swedish (PEDOI).

The well established effect of word frequency on adult's picture naming performance is now called into question. This is particularly true for variables which are correlated with frequency, as is the case of age of word acquisition. Since the work of [Carrol and White, 1973] there is growing agreement among researchers to confer an important role in lexical access to this variable. Indeed, it has been shown ( [Hodgson and Ellis, 1998]) that for normal English-speaking adults only the variables 'age-of-acquisition' and 'name agreement' are independent predictors of naming success among the various variables considered. However, when brain-damaged subjects with and without degenerative pathologies are studied, word frequency and word length as well as concept familiarity all give significant effects ( [Hirsh and Funnell, 1995]; [Lambon Ralph et al., 1998]; [Nickels and Howard, 1995]). Finally, it has been suggested that the production of specific error types may be related to such variables. According to [Nickels and Howard, 1994] the production of semantic errors is specifically affected by 'imageability' and in the recent study by [Kremin et al., 2001] 'age of acquisition' predicts (frank) word finding difficulties.

Adolescent↗