Charting the psychophysiological multiverse: Transparent decisions from theory to inference.

Psychophysiological research requires choices at every stage, from theory and construct definition to task design, preprocessing, and statistical modeling. Because many of these choices are defensible, a single research question can yield a range of plausible results, complicating inference, transparency, and replicability. This special issue showcases how multiverse analyses can systematically evaluate reasonable alternatives and their influence on outcomes in psychophysiology. Multiverse analyses treat datasets as one possible outcome among many, mapping how decisions shape effect estimates and subsequent inferences. This special issue illustrates multiverse thinking across four domains: (1) hypothesis and construct operationalization, including comparisons of contradictory theoretical accounts and alternative psychophysiological indices; (2) experimental design and task selection, clarifying when effects generalize across paradigms versus depend on task context; (3) data processing pipelines, highlighting which preprocessing steps impact data quality and which are comparatively benign; and (4) statistical models, testing the stability of findings across analytic specifications. Collectively, these contributions provide practical guidance for planning, executing, and transparently reporting multiverse analyses in psychophysiology. This introduction to the special issue offers a roadmap for integrating conceptual and analytic multiverses, emphasizing principled decision making, explicit justification of alternatives, and weighting evidence across analyses. Adopting a multiverse perspective from study conception through analysis can strengthen theoretical precision, identify fragile or robust effects, reconcile discrepant literatures, and improve reproducibility. Multiverse practices can ultimately enhance the robustness, rigor, and interpretability of psychophysiological science and support cumulative knowledge building.