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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.


Related in: MedlinePlus

Cortical activation during motor tasks detected using oxy-hemoglobin (HbO) responses. (a) Left lateral view of volume rendered brain with bounding box showing region displayed on other two panels. (b) Main effects of motor execution task, and (c) main effects of motor imagery task. A conventional SPM analysis was applied to fNIRS data, and the resultant F-statistic maps were thresholded at a voxel level of p < 0.000001 (corrected). Results show that SMA is significantly activated during both motor execution and imagery tasks, whereas M1 was only activated during motor execution. Two regions of interest for the DCM analysis were selected using the local maxima of the F-statistics closest to M1 and lateral SMA.
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f0020: Cortical activation during motor tasks detected using oxy-hemoglobin (HbO) responses. (a) Left lateral view of volume rendered brain with bounding box showing region displayed on other two panels. (b) Main effects of motor execution task, and (c) main effects of motor imagery task. A conventional SPM analysis was applied to fNIRS data, and the resultant F-statistic maps were thresholded at a voxel level of p < 0.000001 (corrected). Results show that SMA is significantly activated during both motor execution and imagery tasks, whereas M1 was only activated during motor execution. Two regions of interest for the DCM analysis were selected using the local maxima of the F-statistics closest to M1 and lateral SMA.

Mentions: Prior to DCM analysis, brain regions whose dynamics are driven by experimental conditions were identified using Statistical Parametric Mapping (SPM) analysis (Friston et al., 1995; Ye et al., 2009). Specifically, the HbO response was calculated from fNIRS data using the modified Beer–Lambert law (Delpy et al., 1988), and was subject to SPM analysis with the canonical hemodynamic response function plus its temporal and dispersion derivatives. Statistical significance was assessed using F-tests and the resulting statistical maps were thresholded at a voxel level of p < 0.000001, corrected using random field theory in the usual way. We found that SMA was significantly activated during both motor execution and motor imagery, whereas M1 was only activated during motor execution, as shown in Fig. 4. The most significantly activated voxels within SMA and M1 were then selected as the source positions for DCM analysis: The MNI coordinates are: SMA, [− 51, − 4, 55]; and M1, [− 44, − 16, 65].


Dynamic causal modelling for functional near-infrared spectroscopy.

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

Cortical activation during motor tasks detected using oxy-hemoglobin (HbO) responses. (a) Left lateral view of volume rendered brain with bounding box showing region displayed on other two panels. (b) Main effects of motor execution task, and (c) main effects of motor imagery task. A conventional SPM analysis was applied to fNIRS data, and the resultant F-statistic maps were thresholded at a voxel level of p < 0.000001 (corrected). Results show that SMA is significantly activated during both motor execution and imagery tasks, whereas M1 was only activated during motor execution. Two regions of interest for the DCM analysis were selected using the local maxima of the F-statistics closest to M1 and lateral SMA.
© Copyright Policy - CC BY-NC-ND
Related In: Results  -  Collection

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

f0020: Cortical activation during motor tasks detected using oxy-hemoglobin (HbO) responses. (a) Left lateral view of volume rendered brain with bounding box showing region displayed on other two panels. (b) Main effects of motor execution task, and (c) main effects of motor imagery task. A conventional SPM analysis was applied to fNIRS data, and the resultant F-statistic maps were thresholded at a voxel level of p < 0.000001 (corrected). Results show that SMA is significantly activated during both motor execution and imagery tasks, whereas M1 was only activated during motor execution. Two regions of interest for the DCM analysis were selected using the local maxima of the F-statistics closest to M1 and lateral SMA.
Mentions: Prior to DCM analysis, brain regions whose dynamics are driven by experimental conditions were identified using Statistical Parametric Mapping (SPM) analysis (Friston et al., 1995; Ye et al., 2009). Specifically, the HbO response was calculated from fNIRS data using the modified Beer–Lambert law (Delpy et al., 1988), and was subject to SPM analysis with the canonical hemodynamic response function plus its temporal and dispersion derivatives. Statistical significance was assessed using F-tests and the resulting statistical maps were thresholded at a voxel level of p < 0.000001, corrected using random field theory in the usual way. We found that SMA was significantly activated during both motor execution and motor imagery, whereas M1 was only activated during motor execution, as shown in Fig. 4. The most significantly activated voxels within SMA and M1 were then selected as the source positions for DCM analysis: The MNI coordinates are: SMA, [− 51, − 4, 55]; and M1, [− 44, − 16, 65].

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.


Related in: MedlinePlus