Jens Brauer - Academia.edu (original) (raw)

Papers by Jens Brauer

Frontiers for Young Minds, 2014

Typological Studies in Language, 2009

ACS chemical biology, Jan 16, 2015

Shaping the temporal response of photoreceptors is facilitated by a well-balanced second messenge... more Shaping the temporal response of photoreceptors is facilitated by a well-balanced second messenger cascade, in which two neuronal Ca(2+)-sensor proteins operate in a sequential relay mechanism. Although they share structurally similar sensing units, they differentially activate the same target protein. Here, as a prototypical case in Ca(2+)-mediated signal processing, we investigate differential cellular responsiveness in protein conformational dynamics on a nanosecond time scale. For this, we have site-specifically labeled cysteine residues in guanylate cyclase-activating protein GCAP1 by the fluorescent dye Alexa647 and probed its local environment via time-resolved fluorescence spectroscopy. Fluorescence lifetime and rotational anisotropy measurements reveal a distinct structural movement of the polypeptide chain around position 106 upon release of Ca(2+). This is supported by analyzing the diffusional dye motion in a wobbling-in-a-cone model and by molecular dynamics simulations...

This chapter summarizes the extensive discussions that took place during the Forum as well as in ... more This chapter summarizes the extensive discussions that took place during the Forum as well as in the subsequent months thereafter. It assesses current understanding of the neuronal mechanisms that underlie syntactic structure and processing…. It is posited that to understand the neurobiology of syntax, it might be worthwhile to shift the balance from comprehension to syntactic encoding in language production

Cerebral Cortex

Low-frequency fluctuations (LFFs) are a major source of variation in fMRI data. This has been est... more Low-frequency fluctuations (LFFs) are a major source of variation in fMRI data. This has been established in numerous experiments-particularly in the resting state. Here we investigate LFFs in a task-dependent setting. We hypothesized that LFFs may contain information about cognitive networks that are specific to the overall task domain without being time locked to stimulus onsets. We analyzed data of 6 fMRI experiments, 4 of which belonged to the language domain. After regressing out specifics of the experimental design and low-pass filtering (<0.1 Hz), we found that the 4 language experiments produced a correlational pattern that was not present in the 2 nonlanguage studies. Specifically, a region in the posterior part of the left superior temporal sulcus/gyrus was consistently correlated with both the left Brodmann's area 44 and the left frontal operculum in all 4 language studies, whereas this correlation was not found in the 2 other experiments. This finding indicates th...

NeuroImage, Jan 12, 2015

Phonological awareness is the best-validated predictor of reading and spelling skill and therefor... more Phonological awareness is the best-validated predictor of reading and spelling skill and therefore highly relevant for developmental dyslexia. Prior imaging genetics studies link several dyslexia risk genes to either brain-functional or brain-structural factors of phonological deficits. However, coherent evidence for genetic associations with both functional and structural neural phenotypes underlying variation in phonological awareness has not yet been provided. Here we demonstrate that rs11100040, a reported modifier of SLC2A3, is related to the functional connectivity of left fronto-temporal phonological processing areas at resting state in a sample of 9- to 12-year-old children. Furthermore, we provide evidence that rs11100040 is related to the fractional anisotropy of the arcuate fasciculus, which forms the structural connection between these areas. This structural connectivity phenotype is associated with phonological awareness, which is in turn associated with the individual ...

Cerebral cortex (New York, N.Y. : 1991), Jan 13, 2015

The relation between brain function and behavior on the one hand and the relation between structu... more The relation between brain function and behavior on the one hand and the relation between structural changes and behavior on the other as well as the link between the 2 aspects are core issues in cognitive neuroscience. It is an open question, however, whether brain function or brain structure is the better predictor for age-specific cognitive performance. Here, in a comprehensive set of analyses, we investigated the direct relation between hemodynamic activity in 2 pairs of frontal and temporal cortical areas, 2 long-distance white matter fiber tracts connecting each pair and sentence comprehension performance of 4 age groups, including 3 groups of children between 3 and 10 years as well as young adults. We show that the increasing accuracy of processing complex sentences throughout development is correlated with the blood-oxygen-level-dependent activation of 2 core language processing regions in Broca's area and the posterior portion of the superior temporal gyrus. Moreover, b...

Brain : a journal of neurology, Jan 19, 2015

In their recent report in Brain, Clark et al. (2014) presented cortical thickness data obtained f... more In their recent report in Brain, Clark et al. (2014) presented cortical thickness data obtained from a cohort of 27 children that were compared longitudinally at three time points (first grade: ages 6-7, third grade: ages 8-9, sixth grade: ages 11-12) categorized as either dyslexic or not according to their reading outcome in sixth grade. Based on their observations, the authors conclude that the neuroanatomical precursors of developmental dyslexia are found predominantly in primary sensory cortices and that structural abnormalities in the reading network only emerge after children have learned how to read and write. This study is indeed invaluable as it follows preliterate children longitudinally until the disorder is diagnosed, providing a unique picture of structural cortical changes in dyslexic and non-dyslexic children during this time. However, there are a number of discrepancies between the presented findings and results from other groups including our own. These differences might be explained by the relatively low statistical power of the analyses carried out by Clark and colleagues. Moreover, because genetic and environmental factors are not included in their analyses, it remains unclear how the data can be integrated into a comprehensive account of developmental dyslexia.

NeuroImage, Jan 15, 2014

An essential computational component of the human language faculty is syntax as it regulates how ... more An essential computational component of the human language faculty is syntax as it regulates how words are combined into sentences. Although its neuroanatomical basis is well-specified in adults, its emergence in the maturing brain is not yet understood. Using event-related functional magnetic resonance imaging (fMRI) in a cross-sectional design, we discovered, that in contrast to what is known about adults 3-to-4- and 6-to-7-year-old children do not process syntax independently from semantics at the neural level already before these two types of information are integrated for the interpretation of a sentence. It is not until the end of the 10th year of life that children show a neural selectivity for syntax, segregated and gradually independent from semantics, in the left inferior frontal cortex as in the adult brain. Our results indicate that it takes until early adolescence for the domain-specific selectivity of syntax within the language network to develop.

Beilstein journal of nanotechnology, 2013

We investigate the radiation patterns of sharp conical gold tapers, which were designed as adiaba... more We investigate the radiation patterns of sharp conical gold tapers, which were designed as adiabatic nanofocusing probes for scanning near-field optical microscopy (SNOM). Field calculations show that only the lowest order eigenmode of such a taper can reach the very apex and thus induce the generation of strongly enhanced near-field signals. Higher-order modes are coupled into the far field at finite distances from the apex. Here, we demonstrate experimentally how to distinguish and separate between the lowest and higher-order eigenmodes of such a metallic taper by filtering in the spatial frequency domain. Our approach has the potential to considerably improve the signal-to-background ratio in spectroscopic experiments at the nanoscale.

When we observe the behavior of others, motor systems that are active in the observed are also ac... more When we observe the behavior of others, motor systems that are active in the observed are also active in the observer. In this experiment we asked whether this ‘mirror-like’ activity is present in the error-monitoringsystem,when we observe errors committed,by others. Subjects performed a choice-reaction time task and observed a ‘virtual’ subject performing the same task. In the latter case,

Biological Foundations and Origin of Syntax, 2009

Social Neuroscience, 2010

The recognition of emotional expressions is an important skill and relates to social functioning ... more The recognition of emotional expressions is an important skill and relates to social functioning and adjustment in childhood. The current functional MRI study investigated the neural processing of angry and happy facial expressions in 5-to 6year-old children and in adults. Participants were presented happy and angry faces of adults and children while they performed a non-emotion-related task with low cognitive load. Very similar neural networks were involved in the processing of angry and happy faces in adults and children, including the amygdala and prefrontal areas.

Psychological Research, 2012

Although the neural network for language processing in the adult brain is well specified, the neu... more Although the neural network for language processing in the adult brain is well specified, the neural underpinning of language acquisition is still underdetermined. Here, we define the milestones of syntax acquisition and discuss the possible neurophysiological preconditions thereof. Early language learning seems to be based on the bilateral temporal cortices. Subsequent syntax acquisition apparently primarily recruits a neural network involving the left frontal cortex and the temporal cortex connected by a ventrally located fiber system. The late developing ability to comprehend syntactically complex sentences appears to require a neural network that connects Broca&amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s area to the left posterior temporal cortex via a dorsally located fiber pathway. Thus, acquisition of syntax requires the maturation of fiber bundles connecting the classical language-relevant brain regions.

PLoS ONE, 2011

Language development must go hand-in-hand with brain maturation. Little is known about how the br... more Language development must go hand-in-hand with brain maturation. Little is known about how the brain develops to serve language processing, in particular, the processing of complex syntax, a capacity unique to humans. Behavioral reports indicate that the ability to process complex syntax is not yet adult-like by the age of seven years. Here, we apply a novel method to demonstrate that the basic neural basis of language, as revealed by low frequency fluctuation stemming from functional MRI data, differs between six-year-old children and adults in crucial aspects. Although the classical language regions are actively in place by the age of six, the functional connectivity between these regions clearly is not. In contrast to adults who show strong connectivities between frontal and temporal language regions within the left hemisphere, children's default language network is characterized by a strong functional interhemispheric connectivity, mainly between the superior temporal regions. These data indicate a functional reorganization of the neural network underlying language development towards a system that allows a close interplay between frontal and temporal regions within the left hemisphere.