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Brain activation during executed (EM) and imagined movements (IM) of the right and left hand was studied in 10 healthy right-handed subjects using functional magnetic resonance imagining (fMRI). Low electromyographic (EMG) activity of the musculi flexor digitorum superficialis and high vividness of the imagined movements were trained prior to image(More)
Functional magnetic resonance imaging was used to determine the activation of the amygdala while seven social phobics and five healthy controls were exposed to slides of neutral faces as well as aversive odor stimuli. The amygdala was selectively activated in the social phobics during presentation of the face stimuli. The data show for the first time that(More)
The term concreteness effect refers to the observation that concrete nouns are processed faster and more accurately than abstract nouns in a variety of cognitive tasks. Two models have been proposed to explain the neuronal basis of the concreteness effect. The dual-coding theory attributes the advantage to the access of a right hemisphere image based system(More)
It is well known that, at higher field strength, T2*-weighted images show an extensive heterogeneity in white matter fiber bundles. The basis of this phenomenon is still under discussion, as many factors, such as iron concentration, myelination and tissue microstructure, could influence relaxation times. Furthermore, fiber direction in relation to the main(More)
The potential of functional magnetic resonance imaging (fMRI) for experimental studies of the brain and behavior considerable given its superior time and spatial resolution, but few studies have attempted to validate them against established methods for measuring cerebral activation. In a previous study absolute regional cerebral blood flow was measured in(More)
An increased daily alcohol consumption results in neurological symptoms and morphological central nervous system changes, e.g. shrinkage of the frontal lobes and the cerebellar vermis. Brain shrinkage can be due to neuronal loss, gliosis, or alterations of (cell) membrane constitutes/myelin. Neuronal, glial, and metabolic changes can be measured in vivo(More)
Short echo time (TE) proton MR spectra of the brain include signals of several metabolites as well as macromolecules. In various pathologies, such as brain tumors and multiple sclerosis (MS), the presence of mobile lipids or pathologically altered macromolecules may provide useful additional diagnostic information. A reliable quantitation of these(More)
The flow of cerebrospinal fluid (CSF) through the aqueduct was studied with an echoplanar imaging technique. Images (1024) of a slice perpendicular to the aqueduct were acquired with a repetition time of 107 msec and a flip angle of 90 degrees. This imaging technique is very sensitive for flow into the selected slice, although a quantitative assessment of(More)
In vivo longitudinal relaxation times of N-acetyl compounds (NA), choline-containing substances (Cho), creatine (Cr), myo-inositol (mI), and tissue water were measured at 1.5 and 3 T using a point-resolved spectroscopy (PRESS) sequence with short echo time (TE). T(1) values were determined in six different brain regions: the occipital gray matter (GM),(More)
Recent blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging studies have shown a reduction of cerebral activation during aging, which may be associated with age-related changes of the cerebral vascular system. The authors used a global hypercapnic breath-holding challenge to define nonneuronal contributions to a significantly(More)