Preprocessing on the Go: Practices in Gait-Related Mobile EEG

Mobile EEG has become popular in investigating brain dynamics during gait in recent years. Within this development, new preprocessing pipelines have been introduced and refined. The diversity of approaches, however, complicates comparisons across studies. To provide clarity, we reviewed studies that combined mobile EEG with gait measurements to map the preprocessing pipelines used in the field. Our review identified substantial heterogeneity in pipeline steps, their order, combinations, and the level of reporting detail. We visualized this heterogeneity as a map, tracing pathways from raw data to outcomes such as Power spectral density (PSD), Event-related spectral perturbations (ERSP), Event-related (de-) synchronization (ERD/ERS), and Corticomuscular coherence (CMC), along with a subsequent analysis highlighting unique pipelines. Notably, artifact rejection varied across studies in both the tools used and reporting practices. While differences in hardware, setup, and experimental paradigms can justify this variability, they also challenge comparability across findings. These results emphasize the need for transparent reporting standards and provide a foundation for future efforts toward developing shared standards in the mobile EEG community.