@article{VernerHerrmannTrocheetal.2013,
  author    = {Verner, Martin and Herrmann, Martin J. and Troche, Stefan J. and Roebers, Claudia M. and Rammsayer, Thomas H.},
  title     = {Cortical oxygen consumption in mental arithmetic as a function of task difficulty: a near-infrared spectroscopy approach},
  series = {Frontiers in Human Neuroscience},
  volume    = {7},
  journal   = {Frontiers in Human Neuroscience},
  number    = {217},
  issn      = {1662-5161},
  doi       = {10.3389/fnhum.2013.00217},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-122449},
  year      = {2013},
  abstract  = {The present study investigated changes in cortical oxygenation during mental arithmetic using near-infrared spectroscopy (NIRS). Twenty-nine male volunteers were examined using a 52-channel continuous wave system for analyzing activity in prefrontal areas. With the help of a probabilistic mapping method, three regions of interest (ROIs) on each hemisphere were defined: The inferior frontal gyri (IFG), the middle frontal gyri (MFG), and the superior frontal gyri (SFG). Oxygenation as an indicator of functional brain activation was compared over the three ROI and two levels of arithmetic task difficulty (simple and complex additions). In contrast to most previous studies using fMRI or NIRS, in the present study arithmetic tasks were presented verbally in analogue to many daily life situations. With respect to task difficulty, more complex addition tasks led to higher oxygenation in all defined ROI except in the left IFG compared to simple addition tasks. When compared to the channel positions covering different gyri of the temporal lobe, the observed sensitivity to task complexity was found to be restricted to the specified ROIs. As to the comparison of ROIs, the highest oxygenation was found in the IFG, while MFG and SFG showed significantly less activation compared to IFG. The present cognitive-neuroscience approach demonstrated that NIRS is a suitable and highly feasible research tool for investigating and quantifying neural effects of increasing arithmetic task difficulty.},
  language  = {en}
}
@article{UeceylerKewenigKittelSchneideretal.2015,
  author    = {{\"U}{\c{c}}eyler, Nurcan and Kewenig, Susanne and Kittel-Schneider, Sarah and Fallgatter, Andreas J. and Sommer, Claudia},
  title     = {Increased cortical activation upon painful stimulation in fibromyalgia syndrome},
  series = {BMC Neurology},
  volume    = {15},
  journal   = {BMC Neurology},
  number    = {210},
  doi       = {10.1186/s12883-015-0472-4},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-125230},
  year      = {2015},
  abstract  = {Background Fibromyalgia syndrome (FMS) is a chronic condition characterized by widespread pain and associated symptoms. We investigated cerebral activation in FMS patients by functional near-infrared spectroscopy (fNIRS). Methods Two stimulation paradigms were applied: a) painful pressure stimulation at the dorsal forearm; b) verbal fluency test (VFT). We prospectively recruited 25 FMS patients, ten patients with unipolar major depression (MD) without pain, and 35 healthy controls. All patients underwent neurological examination and all subjects were investigated with questionnaires (pain, depression, FMS, empathy). Results FMS patients had lower pressure pain thresholds than patients with MD and controls (p < 0.001) and reported higher pain intensity (p < 0.001). Upon unilateral pressure pain stimulation fNIRS recordings revealed increased bilateral cortical activation in FMS patients compared to controls (p < 0.05). FMS patients also displayed a stronger contralateral activity over the dorsolateral prefrontal cortex in direct comparison to patients with MD (p < 0.05). While all three groups performed equally well in the VFT, a frontal deficit in cortical activation was only found in patients with depression (p < 0.05). Performance and cortical activation correlated negatively in FMS patients (p < 0.05) and positively in patients with MD (p < 0.05). Conclusion Our data give further evidence for altered central nervous processing in patients with FMS and the distinction between FMS and MD.},
  language  = {en}
}