Impacts of analytic workflows and modeling decisions on the estimated task fMRI activity.

Brisbane Convention & Exhibition Centre 

Functional magnetic resonance imaging (fMRI) tasks often produce signals that are difficult to detect, especially when studying individual differences (Poldrack et al., 2017, Elliott et al., 2020). Researchers often prioritize power in their analytic workflows by reducing collinearity (Liu et al., 2001). The Monetary Incentive Delay (MID; Knutson et al., [2001]) task has a multi-component trial structure that can exacerbate biases in the estimated BOLD activity when behavioral and BOLD timeseries are misaligned and subject-level models omit task-relevant regressors. Here, we highlight a GE timing issue and important model misspecification in MID subject-level models, and its impact on the estimated BOLD activity released as part of the Adolescent Brain Cognitive Development (ABCD) study® fMRI data.