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Dynamic causal modelling for functional near-infrared spectroscopy.

Tak S, Kempny AM, Friston KJ, Leff AP, Penny WD - Neuroimage (2015)

Bottom Line: Specifically, we present a generative model of how observed fNIRS data are caused by interactions among hidden neuronal states.Inversion of this generative model, using an established Bayesian framework (variational Laplace), then enables inference about changes in directed connectivity at the neuronal level.Using experimental data acquired during motor imagery and motor execution tasks, we show that directed (i.e., effective) connectivity from the supplementary motor area to the primary motor cortex is negatively modulated by motor imagery, and this suppressive influence causes reduced activity in the primary motor cortex during motor imagery.

View Article: PubMed Central - PubMed

Affiliation: Wellcome Trust Centre for Neuroimaging, University College London, 12 Queen Square, London WC1N 3BG, UK. Electronic address: s.tak@ucl.ac.uk.

No MeSH data available.


Geometry of the optical probes. S, D, and Ch denote optical source, optical detector, and channel, respectively. The distance between the source and the detector is 2.5 cm.
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f0010: Geometry of the optical probes. S, D, and Ch denote optical source, optical detector, and channel, respectively. The distance between the source and the detector is 2.5 cm.

Mentions: The optical density changes during motor execution and imagery were acquired using a continuous wave fNIRS instrument (NIRScout, NIRx, Medizintechnik, GmbH, Germany). The fNIRS system had 16 channels for bilateral placements, consisting of 2 optical sources with wavelengths of 760 nm and 850 nm, and 6 optical detectors. The supplementary motor area (SMA) and primary motor cortex (M1) of both hemispheres were covered within the optical holder cap. However, only fNIRS data from the left hemisphere was used in this study, as our goal was to study the contralateral activation of brain regions during right hand movement. The sampling frequency was 10.4 Hz. The distance between the optical source and the detector was 2.5 cm. The geometry of optical probes on the left hemisphere is shown in Fig. 2.


Dynamic causal modelling for functional near-infrared spectroscopy.

Tak S, Kempny AM, Friston KJ, Leff AP, Penny WD - Neuroimage (2015)

Geometry of the optical probes. S, D, and Ch denote optical source, optical detector, and channel, respectively. The distance between the source and the detector is 2.5 cm.
© Copyright Policy - CC BY-NC-ND
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4401444&req=5

f0010: Geometry of the optical probes. S, D, and Ch denote optical source, optical detector, and channel, respectively. The distance between the source and the detector is 2.5 cm.
Mentions: The optical density changes during motor execution and imagery were acquired using a continuous wave fNIRS instrument (NIRScout, NIRx, Medizintechnik, GmbH, Germany). The fNIRS system had 16 channels for bilateral placements, consisting of 2 optical sources with wavelengths of 760 nm and 850 nm, and 6 optical detectors. The supplementary motor area (SMA) and primary motor cortex (M1) of both hemispheres were covered within the optical holder cap. However, only fNIRS data from the left hemisphere was used in this study, as our goal was to study the contralateral activation of brain regions during right hand movement. The sampling frequency was 10.4 Hz. The distance between the optical source and the detector was 2.5 cm. The geometry of optical probes on the left hemisphere is shown in Fig. 2.

Bottom Line: Specifically, we present a generative model of how observed fNIRS data are caused by interactions among hidden neuronal states.Inversion of this generative model, using an established Bayesian framework (variational Laplace), then enables inference about changes in directed connectivity at the neuronal level.Using experimental data acquired during motor imagery and motor execution tasks, we show that directed (i.e., effective) connectivity from the supplementary motor area to the primary motor cortex is negatively modulated by motor imagery, and this suppressive influence causes reduced activity in the primary motor cortex during motor imagery.

View Article: PubMed Central - PubMed

Affiliation: Wellcome Trust Centre for Neuroimaging, University College London, 12 Queen Square, London WC1N 3BG, UK. Electronic address: s.tak@ucl.ac.uk.

No MeSH data available.