@article{KopfGloecknerAlthenetal.2023,
  author    = {Kopf, Juliane and Gl{\"o}ckner, Stefan and Althen, Heike and Cevada, Thais and Schecklmann, Martin and Dresler, Thomas and Kittel-Schneider, Sarah and Reif, Andreas},
  title     = {Neural responses to a working memory task in acute depressed and remitted phases in bipolar patients},
  series = {Brain Sciences},
  volume    = {13},
  journal   = {Brain Sciences},
  number    = {5},
  issn      = {2076-3425},
  doi       = {10.3390/brainsci13050744},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-313509},
  year      = {2023},
  abstract  = {(1) Cognitive impairments such as working memory (WM) deficits are amongst the most common dysfunctions characterizing bipolar disorder (BD) patients, severely contributing to functional impairment. We aimed to investigate WM performance and associated brain activation during the acute phase of BD and to observe changes in the same patients during remission. (2) Frontal brain activation was recorded using functional near-infrared spectroscopy (fNIRS) during n-back task conditions (one-back, two-back and three-back) in BD patients in their acute depressive (n = 32) and remitted (n = 15) phases as well as in healthy controls (n = 30). (3) Comparison of BD patients during their acute phase with controls showed a trend (p = 0.08) towards lower dorsolateral prefrontal cortex (dlPFC) activation. In the remitted phase, BD patients showed lower dlPFC and ventrolateral prefrontal cortex (vlPFC) activation (p = 0.02) compared to controls. No difference in dlPFC and vlPFC activation between BD patients' phases was found. (4) Our results showed decreased working memory performance in BD patients during the working memory task in the acute phase of disease. Working memory performance improved in the remitted phase of the disease but was still particularly attenuated for the more demanding conditions.},
  language  = {en}
}
@article{SchecklmannGianiTupaketal.2014,
  author    = {Schecklmann, Martin and Giani, Anette and Tupak, Sara and Langguth, Berthold and Raab, Vincent and Polak, Thomas and Varallyay, Csanad and Harnisch, Wilma and Herrmann, Martin J. and Fallgatter, Andreas J.},
  title     = {Functional Near-Infrared Spectroscopy to Probe State- and Trait-Like Conditions in Chronic Tinnitus: A Proof-of-Principle Study},
  series = {Neural Plasticity},
  journal   = {Neural Plasticity},
  number    = {894203},
  issn      = {1687-5443},
  doi       = {10.1155/2014/894203},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-117801},
  pages     = {8},
  year      = {2014},
  abstract  = {Objective. Several neuroscience tools showed the involvement of auditory cortex in chronic tinnitus. In this proof-of-principle study we probed the capability of functional near-infrared spectroscopy (fNIRS) for the measurement of brain oxygenation in auditory cortex in dependence from chronic tinnitus and from intervention with transcranial magnetic stimulation. Methods. Twenty-three patients received continuous theta burst stimulation over the left primary auditory cortex in a randomized sham-controlled neuronavigated trial (verum = 12; placebo = 11). Before and after treatment, sound-evoked brain oxygenation in temporal areas was measured with fNIRS. Brain oxygenation was measured once in healthy controls (n = 12). Results. Sound-evoked activity in right temporal areas was increased in the patients in contrast to healthy controls. Left-sided temporal activity under the stimulated area changed over the course of the trial; high baseline oxygenation was reduced and vice versa. Conclusions. By demonstrating that rTMS interacts with auditory evoked brain activity, our results confirm earlier electrophysiological findings and indicate the sensitivity of fNIRS for detecting rTMS induced changes in brain activity. Moreover, our findings of trait-and state-related oxygenation changes indicate the potential of fNIRS for the investigation of tinnitus pathophysiology and treatment response.},
  language  = {en}
}
@article{HaeussingerHeinzelHahnetal.2011,
  author    = {Haeussinger, Florian B. and Heinzel, Sebastian and Hahn, Tim and Schecklmann, Martin and Ehlis, Ann-Christine and Fallgatter, Andreas J.},
  title     = {Simulation of Near-Infrared Light Absorption Considering Individual Head and Prefrontal Cortex Anatomy: Implications for Optical Neuroimaging},
  series = {PLoS ONE},
  volume    = {6},
  journal   = {PLoS ONE},
  number    = {10},
  doi       = {10.1371/journal.pone.0026377},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-142311},
  pages     = {e26377},
  year      = {2011},
  abstract  = {Functional near-infrared spectroscopy (fNIRS) is an established optical neuroimaging method for measuring functional hemodynamic responses to infer neural activation. However, the impact of individual anatomy on the sensitivity of fNIRS measuring hemodynamics within cortical gray matter is still unknown. By means of Monte Carlo simulations and structural MRI of 23 healthy subjects (mean age: (25.0 +/- 2.8) years), we characterized the individual distribution of tissue-specific NIR-light absorption underneath 24 prefrontal fNIRS channels. We, thereby, investigated the impact of scalp-cortex distance (SCD), frontal sinus volume as well as sulcal morphology on gray matter volumes (V(gray)) traversed by NIR-light, i.e. anatomy-dependent fNIRS sensitivity. The NIR-light absorption between optodes was distributed describing a rotational ellipsoid with a mean penetration depth of (23.6 +/- 0.7) mm considering the deepest 5\% of light. Of the detected photon packages scalp and bone absorbed (96.4 +/- 9: 7)\% and V(gray) absorbed (3.1 +/- 1.8)\% of the energy. The mean V(gray) volume (1.1 +/- 0.4)cm(3) was negatively correlated (r = - .76) with the SCD and frontal sinus volume (r = - .57) and was reduced by 41.5\% in subjects with relatively large compared to small frontal sinus. Head circumference was significantly positively correlated with the mean SCD (r = .46) and the traversed frontal sinus volume (r = .43). Sulcal morphology had no significant impact on V(gray). Our findings suggest to consider individual SCD and frontal sinus volume as anatomical factors impacting fNIRS sensitivity. Head circumference may represent a practical measure to partly control for these sources of error variance.},
  language  = {en}
}