Quantification of Systemic Interference in Optical Topography Data during Frontal Lobe and Motor Cortex Activation: An Independent Component Analysis
Functional near-infrared optical topography (OT) is used to non-invasively measure the changes in oxygenated and deoxygenated haemoglobin (Δ[HbO2], Δ[HHb]) and hence investigate the brain haemodynamic changes, which occur in response to functional activation at specific regions of the cerebral cortex. However, when analysing functionalOT data the task-related systemic changes should be taken into account.Here we used an independent component analysis (ICA) method on the OT [HbO2] signal, to determine the task-related independent components and then compared them with the systemic measurements (blood pressure, heart rate, scalp blood flow) to assess whether the components are due to systemic noise or neuronal activation. This analysis can therefore extract the true OT haemodynamic neuronal response and hence discriminate between regional activated cortical areas and global haemodynamic changes.
KeywordsIndependent Component Analysis Independent Component Analysis Haemodynamic Change Mean Blood Pressure Diffuse Optical Imaging
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- 5.Katura T, Sato H, Fuchino Y et al (2008) Extracting task-related activation components from optical topography measurement using independent components analysis. J.Biomed.Opt. 13:054008-Google Scholar
- 7.Ziehe A and Muller KR, (1998) TDSEP an efficient algorithm for blind separation using time structure. Proc.ICANN98, Springer, Berlin 675-680Google Scholar
- 8.Hirosaka R, Katura T, Kawaguchi H et al (15-7-2004) Noisy time-delayed decorrelation and its application to extraction of neural activity from single optical recordings in guinea pigs. Physica D.: Nonlinear.Phenomena. 194:320-332Google Scholar
- 9.Huppert TJ, Diamond SG, Franceschini MA et al (1-4-2009) HomER: a review of time-series analysis methods for near-infrared spectroscopy of the brain. Appl.Opt. 48:D280-D298Google Scholar