RT Journal Article SR Electronic T1 Interpreting Null Models of Resting-State Functional MRI JF bioRxiv FD Cold Spring Harbor Laboratory SP 2021.03.30.437514 DO 10.1101/2021.03.30.437514 A1 Liégeois, Raphaël A1 Yeo, B. T. Thomas A1 Van De Ville, Dimitri YR 2021 UL http://biorxiv.org/content/early/2021/03/31/2021.03.30.437514.abstract AB Null models are necessary for assessing whether a dataset exhibits non-trivial statistical properties. These models have recently gained interest in the neuroimaging community as means to explore dynamic properties of functional Magnetic Resonance Imaging (fMRI) time series. Interpretation of null-model testing in this context may not be straightforward because (i) null hypotheses associated to different null models are sometimes unclear and (ii) fMRI metrics might be ‘trivial’, i.e. preserved under the null hypothesis, and still be useful in neuroimaging applications. In this commentary, we review several commonly used null models of fMRI time series and discuss the interpretation of the corresponding tests. We argue that, while null-model testing allows for a better characterization of the statistical properties of fMRI time series and associated metrics, it should not be considered as a mandatory validation step to assess their relevance in neuroimaging applications.Competing Interest StatementThe authors have declared no competing interest.