TY  - JOUR
A1  - Verner, Martin
A1  - Herrmann, Martin J.
A1  - Troche, Stefan J.
A1  - Roebers, Claudia M.
A1  - Rammsayer, Thomas H.
T1  - Cortical oxygen consumption in mental arithmetic as a function of task difficulty: a near-infrared spectroscopy approach
JF  - Frontiers in Human Neuroscience
N2  - 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.
KW  - cortical activation
KW  - working memory
KW  - individual differences
KW  - prefrontal cortex
KW  - FMRI
KW  - brain-regions
KW  - subsctraction
KW  - activation
KW  - bold
KW  - intelligibility
KW  - NIRS
KW  - oxygen consumption
KW  - task difficulty
KW  - mental arithmetic
KW  - near-infrared spectroscopy
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-122449
SN  - 1662-5161
VL  - 7
IS  - 217
ER  - 
TY  - JOUR
A1  - Katzorke, Andrea
A1  - Zeller, Julia B. M.
A1  - Müller, Laura D.
A1  - Lauer, Martin
A1  - Polak, Thomas
A1  - Reif, Andreas
A1  - Deckert, Jürgen
A1  - Herrmann, Martin J.
T1  - Reduced activity in the right inferior frontal gyrus in elderly APOE-E4 carriers during a verbal fluency task
JF  - Frontiers in Human Neuroscience
N2  - Apolipoprotein-E4 (APOE-E4) is a major genetic risk factor for developing Alzheimer’s disease (AD). The verbal fluency task (VFT), especially the subtask category fluency, has shown to provide a good discrimination between cognitively normal controls and subjects with AD. Interestingly, APOE-E4 seems to have no effect on the behavioral performance during a VFT in healthy elderly. Thus, the purpose of the present study was to reveal possible compensation mechanisms by investigating the effect of APOE-E4 on the hemodynamic response in non-demented elderly during a VFT by using functional near-infrared spectroscopy (fNIRS). We compared performance and hemodynamic response of high risk APOE-E4/E4, -E3/E4 carriers with neutral APOE-E3/E3 non-demented subjects (N = 288; 70–77 years). No difference in performance was found. APOE-E4/E4, -E3/E4 carriers had a decreased hemodynamic response in the right inferior frontal junction (IFJ) with a corresponding higher response in the left middle frontal gyrus (MFG) during category fluency. Performance was correlated with the hemodynamic response in the MFG. We assume a compensation of decreased IFJ brain activation by utilizing the MFG during category fluency and thus resulting in no behavioral differences between APOE-groups during the performance of a VFT.
KW  - psychiatry
KW  - near-infrared spectroscopy
KW  - verbal fluency task
KW  - apolipoprotein-E4
KW  - Alzheimer's disease
KW  - elderly
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-171892
VL  - 11
ER  -