Uncovering communities of pipelines in the task-fMRI analytical space
This work addresses the challenge of pipeline variability in fMRI analysis for researchers, though it is incremental as it builds on existing methods to better understand pipeline relationships.
The study tackled the problem of inconsistent results from different fMRI analysis pipelines by using community detection to identify subsets of pipelines that yield similar outcomes, finding that these patterns are stable across participant groups but not across tasks, with pipeline differences primarily driven by activation area size and statistic scale.
Analytical workflows in functional magnetic resonance imaging are highly flexible with limited best practices as to how to choose a pipeline. While it has been shown that the use of different pipelines might lead to different results, there is still a lack of understanding of the factors that drive these differences and of the stability of these differences across contexts. We use community detection algorithms to explore the pipeline space and assess the stability of pipeline relationships across different contexts. We show that there are subsets of pipelines that give similar results, especially those sharing specific parameters (e.g. number of motion regressors, software packages, etc.). Those pipeline-to-pipeline patterns are stable across groups of participants but not across different tasks. By visualizing the differences between communities, we show that the pipeline space is mainly driven by the size of the activation area in the brain and the scale of statistic values in statistic maps.