Quantifying the effects of CO2 on the resting BOLD signal
نویسندگان
چکیده
Introduction Low-frequency fluctuations in the blood oxygen level-dependent (BOLD) signal are an important component of ‘physiological noise’ in functional MRI signals. Identification and characterization of these sources is extremely important in order to develop noise reduction strategies and hence obtain more accurate activation maps. Spontaneous low frequency fluctuations in arterial carbon dioxide (CO2) have previously been identified as an important factor in the resting BOLD signal through the use of linear regression analysis. However, it is well known that there is a strongly frequency dependent relationship between CO2 and CBF, in which CO2 effects are concentrated in the low frequency range 0-0.05Hz. We therefore hypothesize that the effects of CO2 on the resting state BOLD signal are also restricted within low frequencies and investigate the frequency-dependent effects of CO2 on the resting state BOLD signal by using wavelet cross-correlation analysis.
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