A large number of fMRI studies have shown that the temporal dynamics of
evoked BOLD responses can be highly heterogeneous. Failing to model
heterogeneous responses in statistical analysis can lead to significant errors
in signal detection and characterization and alter the neurobiological
interpretation. However, to date it is not clear that, out of a large number of
options, which methods are robust against variability in the temporal dynamics
of BOLD responses in block-design studies. Here, we used rodent optogenetic fMRI
data with heterogeneous BOLD responses and simulations guided by experimental
data as a means to investigate different analysis methods’ performance
against heterogeneous BOLD responses. Evaluations are carried out within the
general linear model (GLM) framework and consist of standard basis sets as well
as independent component analysis (ICA). Analyses show that, in the presence of
heterogeneous BOLD responses, conventionally used GLM with a canonical basis set
leads to considerable errors in the detection and characterization of BOLD
responses. Our results suggest that the 3rd and 4th order
gamma basis sets, the 7th to 9th order finite impulse
response (FIR) basis sets, the 5th to 9th order B-spline
basis sets, and the 2nd to 5th order Fourier basis sets
are optimal for good balance between detection and characterization, while the
1st order Fourier basis set (coherence analysis) used in our
earlier studies show good detection capability. ICA has mostly good detection
and characterization capabilities, but detects a large volume of spurious
activation with the control fMRI data.