Publications by authors named "Annette Baumgaertner"

Purpose: To examine the effectiveness of communication-oriented group therapy for non-progressive dysarthria regarding functional speech and communicative participation.

Method: Prospective two-arm randomised controlled trial, targeting communication-oriented dysarthria group therapy (DGT). A non-specific social group program served as the control condition/group (CG).

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Apraxia of speech is a motor speech disorder that occurs after lesions to the left cerebral hemisphere, most often concomitant with aphasia. It requires specific approaches in the study of its physiological and neuroanatomical basis and special expertise in clinical care. Knowing its prevalence in patients with aphasia after stroke is therefore relevant for planning specific resources in clinical research and in health care provision.

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Background: Treatment guidelines for aphasia recommend intensive speech and language therapy for chronic (≥6 months) aphasia after stroke, but large-scale, class 1 randomised controlled trials on treatment effectiveness are scarce. We aimed to examine whether 3 weeks of intensive speech and language therapy under routine clinical conditions improved verbal communication in daily-life situations in people with chronic aphasia after stroke.

Methods: In this multicentre, parallel group, superiority, open-label, blinded-endpoint, randomised controlled trial, patients aged 70 years or younger with aphasia after stroke lasting for 6 months or more were recruited from 19 inpatient or outpatient rehabilitation centres in Germany.

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Previous neuroimaging studies demonstrated that a network of left-hemispheric frontal and temporal brain regions contributes to the integration of contextual information into a sentence. However, it remains unclear how these cortical areas influence and drive each other during contextual integration. The present study used dynamic causal modeling (DCM) to investigate task-related changes in the effective connectivity within this network.

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This study investigates structural connectivity between left fronto-parietal brain regions that were identified in a previous fMRI study which used different linguistic manipulation tasks. Diffusion-weighted images were acquired from 20 volunteers. Structural connectivity between brain regions from the fMRI study was computed using probabilistic fiber tracking.

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The role of the right hemisphere in aphasia recovery after left hemisphere damage remains unclear. Increased activation of the right hemisphere has been observed after left hemisphere damage. This may simply reflect a release from transcallosal inhibition that does not contribute to language functions.

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Previous studies have demonstrated that the repetition of pseudowords engages a network of premotor areas for articulatory planning and articulation. However, it remains unclear how these premotor areas interact and drive one another during speech production. We used fMRI with dynamic causal modeling to investigate effective connectivity between premotor areas during overt repetition of words and pseudowords presented in both the auditory and visual modalities.

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Despite a growing number of studies, the neurophysiology of adult vocabulary acquisition is still poorly understood. One reason is that paradigms that can easily be combined with neuroscientfic methods are rare. Here, we tested the efficiency of two paradigms for vocabulary (re-) acquisition, and compared the learning of novel words for actions and objects.

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Verbal stimuli often induce right-hemispheric activation in patients with aphasia after left-hemispheric stroke. This right-hemispheric activation is commonly attributed to functional reorganization within the language system. Yet previous evidence suggests that functional activation in right-hemispheric homologues of classic left-hemispheric language areas may partly be due to processing nonlinguistic perceptual features of verbal stimuli.

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Repetition has been shown to activate the so-called 'dorsal stream', a network of temporo-parieto-frontal areas subserving the mapping of acoustic speech input onto articulatory-motor representations. Among these areas, a region in the posterior Sylvian fissure at the temporo-parietal boundary (also called 'area Spt') has been suggested to play a central role particularly with increasing computational demands on phonological processing. Most of the relevant evidence stems from tasks requiring metalinguistic processing.

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Recent functional imaging studies demonstrated that both the left and right supramarginal gyri (SMG) are activated when healthy right-handed subjects make phonological word decisions. However, lesion studies typically report difficulties with phonological processing after left rather than right hemisphere damage. Here, we used a unique dual-site transcranial magnetic stimulation (TMS) approach to test whether the SMG in the right hemisphere contributes to modality-independent (i.

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There is consensus that the left hemisphere plays a dominant role in language processing, but functional imaging studies have shown that the right as well as the left posterior inferior frontal gyri (pIFG) are activated when healthy right-handed individuals make phonological word decisions. Here we used online transcranial magnetic stimulation (TMS) to examine the functional relevance of the right pIFG for auditory and visual phonological decisions. Healthy right-handed individuals made phonological or semantic word judgements on the same set of auditorily and visually presented words while they received stereotactically guided TMS over the left, right or bilateral pIFG (n=14) or the anterior left, right or bilateral IFG (n=14).

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Imitation in speech refers to the unintentional transfer of phonologically irrelevant acoustic-phonetic information of auditory input into speech motor output. Evidence for such imitation effects has been explained within the framework of episodic theories. However, it is largely unclear, which neural structures mediate speech imitation and how imitation is related with verbal repetition.

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Verbal repetition is conventionally considered to require motor-reproduction of only the phonologically relevant content of a perceived linguistic stimulus, while imitation of incidental acoustic properties of the stimulus is not an explicit part of this task. Exemplar-based theories of speech processing, however, would predict that imitation beyond linguistic reproduction may occur in word repetition. Five experiments were conducted in which verbal audio-motor translations had to be performed under different conditions.

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Numerous studies have proposed that changes of the human language faculty caused by neural maturation can explain the substantial differences in ultimate attainment of grammatical competences between first language (L1) acquirers and second language (L2) learners. However, little evidence on the effect of neural maturation on the attainment of lexical knowledge in L2 is available. The present functional magnetic resonance study addresses this question via a cross-linguistic neural adaptation paradigm.

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One of the issues debated in the field of bilingualism is the question of a "critical period" for second language acquisition. Recent studies suggest an influence of age of onset of acquisition (AOA) particularly on syntactic processing; however, the processing of word order in a sentence context has not yet been examined specifically. We used functional MRI to examine word order processing in two groups of highly proficient German-French bilinguals who had either acquired French or German after the age of 10, and a third group which had acquired both languages before the age of three.

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We can often understand when actions done by others do or do not reflect their intentions. To investigate the neural basis of this capacity we carried out an fMRI study in which volunteers were presented with video-clips showing actions that did reflect the intention of the agent (intended actions) and actions that did not (non-intended actions). Observation of both types of actions activated a common set of areas including the inferior parietal lobule, the lateral premotor cortex and mesial premotor areas.

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Apart from being increasingly implicated in higher motor control, Broca's area is considered to play an important role in action understanding by coding the motor goal of an action. Moreover, recent findings suggest that parts of Broca's area may be able to code action content in a more abstract fashion, independent of modality, specific movement parameters or effector used. We performed functional magnetic resonance imaging to examine whether in humans processing object-directed hand actions presented either visually as video clips or verbally as spoken sentences relies on the same neural substrates.

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Previous functional imaging studies of chronic stroke patients with aphasia suggest that recovery of language occurs in a pre-existing, bilateral network with an upregulation of undamaged areas and a recruitment of perilesional tissue and homologue right language areas. The present study aimed at identifying the dynamics of reorganization in the language system by repeated functional MRI (fMRI) examinations with parallel language testing from the acute to the chronic stage. We examined 14 patients with aphasia due to an infarction of the left middle cerebral artery territory and an age-matched control group with an auditory comprehension task in an event-related design.

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Evidence conflicts as to whether adults with right hemisphere brain damage (RHD) generate inferences during text comprehension. M. Beeman (1993) reported that adults with RHD fail to activate the lexical-semantic bases of routine bridging inferences, which are necessary for comprehension.

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