So he dismissed their screams and howls as mere reflexes, as meaningless physiological noise.
But the physiological noise differs.
We have previously studied the various sources of physiological noise for spinal cord fMRI at 1.5 T and proposed a physiological noise model (PNM) (Brooks et al., 2008).
Therefore, we explored the impact of adding physiological noise to the simulated data.
The effects of physiological noise may significantly limit the reproducibility and accuracy of BOLD fMRI.
But we expected to estimate the variance component due to physiological noise such as flow, MR spin history effect.
The physiological noise including cardiac and respiratory signals were regressed out from the functional data as other covariates.
The sources of noise are numerous including different kinds of motion artifacts and physiological noise with complex patterns.
However, it is not always clear how to translate these recommendations into practice when considering physiological noise and scanner stability.
The results indicate that the analysis of data containing no physiological noise yields a better performance of the SPM analysis.
In comparison, data-driven methods of physiological noise correction show comparable benefits for both young and old cohorts.
