کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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6267530 | 1614595 | 2016 | 10 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: NIRS-EEG joint imaging during transcranial direct current stimulation: Online parameter estimation with an autoregressive model NIRS-EEG joint imaging during transcranial direct current stimulation: Online parameter estimation with an autoregressive model](/preview/png/6267530.png)
- Transient coupling between EEG 0.5 Hz-11.25 Hz band-power and NIRS oxy-hemoglobin signal in the low frequency (â¤0.1 Hz) regime is proposed during tDCS.
- Time varying autoregressive (ARX) model is presented to track this transient coupling relationship during tDCS.
- Online parameter estimation of the ARX model is presented with a Kalman filter.
- Time varying poles associated with the ARX model were comparable across the healthy subjects during tDCS.
- Time varying zeros associated with the ARX model varied across the healthy subjects during tDCS.
BackgroundTranscranial direct current stimulation (tDCS) has been shown to perturb both cortical neural activity and hemodynamics during (online) and after the stimulation, however mechanisms of these tDCS-induced online and after-effects are not known. Here, online resting-state spontaneous brain activation may be relevant to monitor tDCS neuromodulatory effects that can be measured using electroencephalography (EEG) in conjunction with near-infrared spectroscopy (NIRS).MethodWe present a Kalman Filter based online parameter estimation of an autoregressive (ARX) model to track the transient coupling relation between the changes in EEG power spectrum and NIRS signals during anodal tDCS (2 mA, 10 min) using a 4 Ã 1 ring high-definition montage.ResultsOur online ARX parameter estimation technique using the cross-correlation between log (base-10) transformed EEG band-power (0.5-11.25 Hz) and NIRS oxy-hemoglobin signal in the low frequency (â¤0.1 Hz) range was shown in 5 healthy subjects to be sensitive to detect transient EEG-NIRS coupling changes in resting-state spontaneous brain activation during anodal tDCS. Conventional sliding window cross-correlation calculations suffer a fundamental problem in computing the phase relationship as the signal in the window is considered time-invariant and the choice of the window length and step size are subjective. Here, Kalman Filter based method allowed online ARX parameter estimation using time-varying signals that could capture transients in the coupling relationship between EEG and NIRS signals.ConclusionOur new online ARX model based tracking method allows continuous assessment of the transient coupling between the electrophysiological (EEG) and the hemodynamic (NIRS) signals representing resting-state spontaneous brain activation during anodal tDCS.
Journal: Journal of Neuroscience Methods - Volume 274, 1 December 2016, Pages 71-80