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1

The neural correlates of language processing and its disorders over the life span

100%
Heim S.
Acta Neurobiologiae Experimentalis
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2009
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tom 69
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nr 3
I fi rst present the results of a number of fMRI studies investigating the left-lateralised language network in the human brain. The focus will be here on phonological and lexical processing, which both recruit Broca’s region. These data are summarised in a model which serves as framework for the subsequently presented data. Next, I explore commonalities and differences between primary school children and adults with respect to lexical and phonological processing. In the children, the same networks are involved, but are less specialised as compared to adults. Then, neurocognitive differences between dyslexic and normally reading children for lexical and phonological processing as well as for other cognitive functions relevant for reading are discussed. These functions include auditory and visuo-magnocellular processing, attention, and automatisation. Multivariate testing of these functions reveals different cognitive subtypes of dyslexia. Consequently, a new training approach is outlined. With respect to cognitive functions relevant for reading, fMRI reveals consistent right-hemispheric involvement for dyslexic children, which is regarded to refl ect compensatory processes. Finally, a transfer is made to adult dyslexic processing and to linguistic diffi culties in vascular and neurodegenerative aphasia in middle and older age. This research is funded by BMBF 01GJ0613/01GJ0614/GJ01203907, DFG HE 5204/3-1, and JARA-BRAIN Excellence Initiative.
2

The structure and dynamics of normal language processing: Insights from neuroimaging

100%
Heim S.
Acta Neurobiologiae Experimentalis
|
2005
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tom 65
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nr 1
3

Prosodic pitch accents in language comprehension and production: ERP data and acoustic analyses

63%
Heim S., Alter K.
Acta Neurobiologiae Experimentalis
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2006
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tom 66
|
nr 1
We used event-related potentials (ERPs) and acoustic analyses to investigate the processing of prosodic pitch accents as a function of their position in a sentence. Accents in sentence-medial positions were characterized by a higher fundamental frequency (F0) and an increased duration. They elicited two different negative ERP components around 400 ms, depending on the predictability of the accent. When the accent was predictable, the negativity was fronto-laterally distributed and identified as the previously known Expectancy Negativity. Unpredictable accents elicited a more broadly distributed N400 with a central maximum, reflecting difficulties in semantic processing. For sentence-initial pitch accents, words had a higher F0 but of the same duration as sentence-initial words without pitch accents. These pitch accents elicited a P200 but no negativity in a 400 ms time window. The P200 was modulated by the onset latency of the F0 peak rather than its magnitude. We discuss the possibility of a delayed processing of sentence-initial accents when the actual occurrence of an F0 peak can be identified by comparing the F0 of the sentence-initial word to a reduced F0 of a word occurring later in the sentence.
4

Distinct neural signatures of cognitive subtypes of dyslexia: Effects of lexicality during phonological processing

45%
van Ermingen-Marbach M., Pape-Neumann J., Grande M., Grabowska A., Heim S.
Acta Neurobiologiae Experimentalis
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2013
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tom 73
|
nr 3
The present study investigates the neurobiological basis of two subtypes of dyslexia with either a double deficit (concerning phonological awareness and rapid naming) or a single rapid naming deficit. We compared such groups of German dyslexic primary school children to each other and with good reading children in a phoneme deletion task performed during fMRI scanning. Children heard German words or pseudowords and repeated the remainder of the stimulus while deleting the initial phoneme (e.g. tear - _ear). In four conditions, the input stimulus (word or pseudoword) could either become another word or pseudoword as output. The word-word condition stuck out against all other conditions involving pseudowords: Dyslexics with a double deficit showed a strong response in left areas 44 and 45 in Boca's region, whereas dyslexics with rapid naming difficulties revealed a contralateral effect in right areas 44 and 45. These findings, which were obtained without presenting written or pictorial stimuli, reveal that a double deficit in dyslexia is not the sum of single deficits, but rather involves the interaction of lexical and phonological processing, making strong demands on the left inferior frontal cortex. In general, the results stress the importance of considering subtypes of dyslexia differentially in order to obtain better insights in the neurocognitive mechanisms of impaired and successful reading.
5

The role of phonological awareness in treatments of dyslexic primary school children

45%
Pape-Neumann J., van Ermingen-Marbach M., Grande M., Willmes K., Heim S.
Acta Neurobiologiae Experimentalis
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2015
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tom 75
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nr 1
The present study investigated whether phonological awareness training is an effective intervention to significantly improve reading in German dyslexic third and fourth graders with a phonological awareness deficit, and whether these children can equally benefit from a phonology-based reading training or a visually-based reading training. German speaking dyslexic elementary school children («=30; M=9.8 years) were matched by forming triplets based on IQ, reading quotient and phonological awareness and then randomly assigned to one out of three interventions («=10): a phonological awareness training, a phonology-based reading training (phonics instruction), and a visually-based reading training (repeated reading of sight words). A total of 20 training sessions (30 minutes each) were distributed over four weeks. Typical readers («=10; M=9.5 years) were assigned to the control group. Phonological awareness training directly improves reading comprehension in German dyslexic children with a phonological awareness deficit. However, these children can equally benefit from a visually-based reading training. In contrast, the phonology-based reading training has a direct selective effect on decoding but not on reading comprehension. Despite divergent short-term patterns, long-term improvement of reading comprehension and decoding is similar across all training groups, irrespective of the training method. Phonological awareness may but does not need to be part of reading remediation in dyslexic children with a phonological deficit when learning to read a consistent orthography. Rather, a visually-based reading strategy might compensate for the phonological deficit in dyslexic children after the initial stage of reading acquisition.
6

Why the leash constrains the dog: the impact of semantic associations on sentence production

39%
Sass K., Heim S., Sachs O., Theede K., Muehlhaus J., Krach S., Kircher T.
Acta Neurobiologiae Experimentalis
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2010
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tom 70
|
nr 4
The production of language is one of the most complex and amazing skills in humans. Increasing evidence demonstrated that associative relations (e.g., car - garage) play an important role during concept formation but during speech production the effects and processing of associations are highly debated. Hence, the present study investigated the impact of associations and different SOAs on the production of sentences (Experiment 1) and on naming objects (Experiment 2). In an adapted version of the picture-word interference task, participants were asked to name two pictures using a standardized sentence (e.g., “The car is to the left of the trousers”). Thereby, a simultaneous (SOA = 0 ms) or slightly preceding (SOA = -150 ms) auditory or visual distractor had to be ignored. Distractors were related to the first noun (for example: “The car is to the left to the trousers”, distractor: “garage”) or to the second noun (distractor: “belt”) or unrelated to both nouns (distractor: “bottle ”) of the sentence. At simultaneous presentation, visual and auditory distractors related to the first noun of the sentence prolonged naming responses (i.e., interference). For slightly preceding distractors, only visual presentation induced interference for the first noun of the sentence. During no condition, longer naming responses were found for the second noun of the sentence. These effects suggest that associatively related concepts are active during speech production and can be competitors, i.e., they lead to semantic interference. In Experiment 2, subjects had to name an object (e.g., car) while ignoring a visually presented distractor (e.g., motor). The stimulus set was the same as in Experiment 1. The results showed a facilitation effect if the distractor and the target were associatively related. Overall, the current results provide new insight in the models of speech production: while during single word production, associations facilitate naming, they interfere during sentence production. Hence, associations have an important influence on producing speech but the impact is varied by the context, i.e., single word or sentential.
7

Cognitive subtypes of dyslexia

33%
Heim S., Tschierse J., Amunts K., Wilms M., Vossel S., Willmes K., Grabowska A., Huber W.
Acta Neurobiologiae Experimentalis
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2008
|
tom 68
|
nr 1
Different theories conceptualise dyslexia as either a phonological, attentional, auditory, magnocellular, or automatisation deficit. Such heterogeneity suggests the existence of yet unrecognised subtypes of dyslexics suffering from distinguishable deficits. The purpose of the study was to identify cognitive subtypes of dyslexia. Out of 642 children screened for reading ability 49 dyslexics and 48 controls were tested for phonological awareness, auditory discrimination, motion detection, visual attention, and rhythm imitation. A combined cluster and discriminant analysis approach revealed three clusters of dyslexics with different cognitive deficits. Compared to reading-unimpaired children cluster no. 1 had worse phonological awareness; cluster no. 2 had higher attentional costs; cluster no. 3 performed worse in the phonological, auditory, and magnocellular tasks. These results indicate that dyslexia may result from distinct cognitive impairments. As a consequence, prevention and remediation programmes should be specifically targeted for the individual child's deficit pattern.
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