Ria De Bleser

Acquisition and loss of nouns and verbs: parallel or divergent patterns?

Abstract This paper investigates a possible correspondence between the acquisition and breakdown of the ability to name nouns, verbs and their subcategories. The postulation of a universal developmental sequence, according to which children are predisposed to acquire nouns before verbs, has been challenged by cross-linguistic studies. In the case of acquired language loss in adults, the traditional assumption of a double dissociation between nouns and verbs has also been contested in recent work. Furthermore, subcategories of verbs (e.g. transitives versus intransitives) have been shown to be differentially acquired and affected. In our study, we elicited data on noun and verb processing in language production (picture naming task) from children acquiring German and from German aphasic adults. We will report the results from 240 German children (between 2; 6 and 8 years old) as well as the pattern of loss in 11 German aphasic adults. The results show similar category-specific effects in both populations, with a clear-cut noun advantage and a tendency to prefer intransitive verbs, thus supporting the assumption of a specific parallelism in the patterns of acquisition and loss.

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.

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 Lees, 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.

Visual Agnosia: A Case of Reduced Attentional “Spotlight”?

Abstract A case study is presented of a patient with presenile dementia, for whom the dominant clinical feature from onset was a visual agnosia. The characteristics of the patient’s visual agnosia were investigated in light of her apparent use of a “feature-by-feature” strategy to identify objects. Results from various tasks showed that the patient was unable to use global shape information or other grossly defined property cues characteristic of a “wide angle” attentional processing stage (Treisman, 1988) in object recognition. The patient appeared instead to rely on ‘parts’ or identifying features of the objects for object recognition. The patient showed significant improvement when the size of the drawing was reduced in size, thus suggesting that the disorder may be functionally localized to a reduction of the patient’s attentional “spotlight”.

Morphological processing in Italian agrammatic speakers : Eight experiments in lexical morphology

Agrammatic speech production has often been characterized as amorphology. This study of two Italian agrammatic patients shows that, with respect to inflectional morphology of simple and derived nouns, the morphological features of gender and number are almost fully preserved for one patient (MG) and only mildly disturbed in the other patient (DR). Like inflection, the use of derivational suffixation as a means of word-building is only mildly disturbed in both patients. However, they show a severe disturbance with respect to inflectional morphology of lexical compounds, which requires syntactic analysis at the word level. Moreover, they are severely impaired in the choice of the function word for the construction of prepositional compounds, syntactically generated phrases which have the status of a word. Apart from such syntax-dependent morphological and word-building operations, neither inflectional nor derivational morphology are seriously disturbed in our patients. The apparent amorphology in their spontaneous speech can thus not be explained by a disorder of morphological representations in the lexicon system perse. In another study (De Bleser and Luzzatti, 1994) we were able to show that the patients had severe problems with the implementation of morphology in specific syntactic contexts, thus pointing to a problem in morphosyntactic rather than morpholexical processing as a factor contributing to agrammatic speech production.

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.

Analysis of prosody in the spontaneous speech of patients with CV-recurring utterances

We report a study on 9 patients with global aphasia whose language production was restricted to chains of one and the same recurring CV syllable. Length of utterance was determined by the number of syllables between two pauses and major length types were used for pitch analysis. By means of a tonetic method the pitch level of syllables was transcribed so that pitch variations could be established. Our findings contradicted the clinical impression that these patients can convey communicative intentions by means of a variety of fluently produced intonation contours. Even though all patients had a considerable inventory of length types they predominantly used only one or two of them. Pitch types were found to be similarly stereotypical. As an explanation for the fluently produced CV utterances with stereotypical length and pitch, the assumption of iterative motor mechanisms underlying CV speech production was rejected in favour of preserved automatic speech processing and abolished controlled processing.

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 Brocas 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 Brocas 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 Brocas area in processing antecedent‐gap relations was not found. Moreover, the posterior part of Brocas area was conjointly activated by both sentence conditions. Brocas 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. Hum. Brain Mapp. 22:74–83, 2004.

Naming by German compounds

Abstract A picture naming task requiring the correct naming of forty-nine compounds as compared to monomorphemic nouns was given to a group of fifteen German speaking aphasics. The analysis of errors in response to compound targets yielded the following characteristics: semantic paraphasias and phonologically well-formed neologisms tended to reflect the compound structure of the target in a large percentage (73% of 124 verbal paraphasias). Compound paraphasias and neologisms often (48% of 91 compound verbal paraphasias) contained one component of the target. Nearly all errors respected German word building rules. These results suggest that aphasics retain knowledge about the compound status of a word and are able to use compounding rules, although they are unable to retrieve the correct lexical word form. Information of the morphological (compound) form seems therefore to be accessed separately from the lexical word form.

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 pseudowords. 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. Hum Brain Mapp, 2007.