Robust and Unbiased Variance of GLM Coefficients for Misspecified Autocorrelation and Hemodynamic Response Models in fMRI

Figure 2

(a) and (b) Misspecification of the HRF for condition A with the largest relative difference of 0.278 for the event-related design and 0.149 for the blocked design. (c) Three spectra of AR processes are displayed as a function of frequency for [−𝜋,𝜋] [34]. The AR(1) process was generated with parameter 𝜙=0.2, and the two AR(2) processes are generated with 𝛾₁=𝛾₂=0.3, 𝛾₁=0.5, and 𝛾₂=0.4.

(a)

(b)

(c)