We show that the magnitude PSF fails to accurately represent the true effects of k-space sampling and signal decay. As an alternative, we propose to model fMRI with separate MR sampling and signal decay effects. We approximate the latter as a convolution with a Gaussian PSF or, if the effect is that of high-pass filtering, as reversing the effect of a convolution with a Gaussian PSF. At 7T signal decay in SE has a moderate blurring effect (FWHM = 0.89 voxels). Gradient‐Echo acts as a high‐pass filter, reversing blurring with FWHM = 0.59 voxels.