We applied voxel-based morphometry to high-resolution magnetic resonance images of 99 participants with schizophrenia. Voxel-wise correlations with a score of auditory hallucination severity ...identified areas in the left and right superior temporal cortex (including Heschl's gyrus), left supramarginal/angular gyrus, left postcentral gyrus and left posterior cingulate cortex. This study extends previous region-of-interest studies demonstrating main effects of auditory hallucinations related to modality-specific superior temporal areas including primary and secondary auditory cortices.
The KArlsruhe TRItium Neutrino (KATRIN) experiment will measure the absolute mass scale of neutrinos with a sensitivity of mν = 200 meV c2 by high-precision spectroscopy close to the tritium β-decay ...endpoint at 18.6 keV. Its Windowless Gaseous Tritium Source (WGTS) is a β-decay source of high intensity (1011 s−1) and stability, where high-purity molecular tritium at 30 K is circulated in a closed loop with a yearly throughput of 10 kg. To limit systematic effects the column density of the source has to be stabilized at the 10−3 level. This requires extensive sensor instrumentation and dedicated control and monitoring systems for parameters such as the beam tube temperature, injection pressure, gas composition and so on. In this paper, we give an overview of these systems including a dedicated laser-Raman system as well as several β-decay activity monitors. We also report on the results of the WGTS demonstrator and other large-scale test experiments giving proof-of-principle that all parameters relevant to the systematics can be controlled and monitored on the 10−3 level or better. As a result of these works, the WGTS systematics can be controlled within stringent margins, enabling the KATRIN experiment to explore the neutrino mass scale with the design sensitivity.
Recent studies have provided strong evidence that variation in the gene neurocan (NCAN, rs1064395) is a common risk factor for bipolar disorder (BD) and schizophrenia. However, the possible relevance ...of NCAN variation to disease mechanisms in the human brain has not yet been explored. Thus, to identify a putative pathomechanism, we tested whether the risk allele has an influence on cortical thickness and folding in a well-characterized sample of patients with schizophrenia and healthy controls.
Sixty-three patients and 65 controls underwent T1-weighted magnetic resonance imaging (MRI) and were genotyped for the single nucleotide polymorphism (SNP) rs1064395. Folding and thickness were analysed on a node-by-node basis using a surface-based approach (FreeSurfer).
In patients, NCAN risk status (defined by AA and AG carriers) was found to be associated with higher folding in the right lateral occipital region and at a trend level for the left dorsolateral prefrontal cortex. Controls did not show any association (p > 0.05). For cortical thickness, there was no significant effect in either patients or controls.
This study is the first to describe an effect of the NCAN risk variant on brain structure. Our data show that the NCAN risk allele influences cortical folding in the occipital and prefrontal cortex, which may establish disease susceptibility during neurodevelopment. The findings suggest that NCAN is involved in visual processing and top-down cognitive functioning. Both major cognitive processes are known to be disturbed in schizophrenia. Moreover, our study reveals new evidence for a specific genetic influence on local cortical folding in schizophrenia.
We review research suggesting that decisions to trust strangers may not depend on economic dynamics as much as emotional and social ones. Classic treatments of trust emphasize its instrumental or ...consequential nature, proposing that people trust based on expectations that their trust will be honored and the size of reward if it is. Data from our labs, however, focusing on the trust or investment game, suggest that people trust even when their expectations of reward fall below their general tolerance for risk. Further data from our lab suggests that people trust not out of a concern for the consequences of their actions as much as for the actions themselves. The emotions people report feeling about trusting versus withholding trust predicts their decisions much more strongly than the emotions they attach to the potential outcomes. Social dynamics, such as whether participants have been assigned to a specific counterpart in the game, influence whether they trust, even though their economic expectations and payoffs remain unchanged. The dynamics surrounding decisions to trust are complex, and involve social and emotional considerations beyond economic ones.
Alterations in the dopaminergic reward system, predominantly the striatum, constitute core characteristics of schizophrenia.
Functional connectivity of the dorsal striatum during reward-related ...trial-and-error learning was investigated in 17 people with schizophrenia and 18 healthy volunteers and related to striatal grey matter volume and psychopathology.
We used voxel-based morphometry and psychophysiological interaction to examine striatal volume and connectivity.
A reduced functional connectivity between left striatum and temporo-occipital areas, precuneus and insula could be detected in the schizophrenia group. The positive correlation between grey matter volume and functional connectivity of the left striatum yielded significant results in a very similar network. Connectivity of the left striatum was negatively correlated with negative symptoms.
Present results suggest a disruption in striatal functional connectivity that is closely linked to grey matter morphometry of the striatum. Decreased connectivity between the striatum and psychopathologically relevant networks may explain the emergence of negative symptoms.
Objective In patients with major depressive disorder (MDD), enhanced activation of the rostral anterior cingulate cortex (rACC) during conflict resolution has been demonstrated with the use of ...functional magnetic resonance imaging (fMRI), which suggests dysregulation of the affective compartment of the ACC associated with error monitoring and cognitive control. Moreover, several previous studies have reported disrupted structural integrity in limbic brain areas and the orbitofrontal cortex in MDD. However, the relation between structural and functional alterations remains unclear. Therefore, the present study sought to investigate whether structural brain aberrations in terms of grey matter decreases directly in the medial frontal regions or in anatomically closely connected areas might be related to our previously reported functional alterations. Methods A sample of 16 female, drug-free patients with an acute episode of MDD and 16 healthy control subjects matched for age, sex and education were examined with structural high-resolution T1 -weighted MRI; fMRI images were obtained in the same session. Results Voxel-based morphometry (VBM) revealed grey matter decreases in the orbitofrontal and subgenual cortex, in the hippocampus-amygdala complex and in the middle frontal gyrus. The relative hyperactivation of the rACC in terms of inability to deactivate this region during the Stroop Color-Word Test showed an inverse correlation with grey matter reduction in the orbitofrontal cortex. Conclusion The present study provides strong evidence for an association between structural alterations in the orbitofrontal cortex and disturbed functional activation in the emotional compartment of the ACC in patients with MDD during cognitive control.
Schizophrenia is associated with often widespread changes in white matter structure. Most studies have investigated changes in fractional anisotropy, whereas alterations in radial or axial ...diffusivity have barely been investigated until now.
To investigate radial diffusivity as a potential marker of dysmyelination in direct relation to abnormalities in neural activation.
Neural activation in association with decision-making under uncertainty was investigated in 19 people with schizophrenia and 20 healthy controls and linked to radial diffusivity as measured by diffusion tensor imaging.
Decision-making under uncertainty was associated with a significantly decreased activation in a frontostriatocingulate network in the schizophrenia group. Structurally, they exhibited increased radial diffusivity in temporal white matter that was negatively correlated with activation in parts of the frontostriatocingulate network.
Present data indicate that altered diffusivity within relevant white matter networks may be closely linked to abnormal neural activation in schizophrenia.
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