Multiverse analyses in fear conditioning research
There is heterogeneity in and a lack of consensus on the preferred statistical analyses foranalyzing fear conditioning effects in light of a multitude of potentially equally justifiablestatistical approaches. Here, we introduce the concept of multiverse analysis for fearconditioning research. We also present a model multiverse approach specifically tailored tofear conditioning research and introduce the novel and easy to use R package ‘multifear’ thatallows to run all the models though a single line of code. Model specifications and datareduction approaches employed in the ‘multifear’ package were identified through arepresentative systematic literature search. The heterogeneity of statistical models identifiedincluded Bayesian ANOVA and t-tests as well as frequentist ANOVA, t-test as well as mixedmodels with a variety of data reduction approaches (i.e., number of trials, trial blocks,averages) as input. We illustrate the power of a multiverse analysis for fear conditioning databased on two pre-existing data sets with partial (data set 1) and 100% reinforcement rate(data set 2) by using CS discrimination in skin conductance responses (SCRs) during fearacquisition and extinction training as case examples. Both the effect size and the direction ofeffect was impacted by choice of the model and data reduction techniques. We anticipatethat an increase in multiverse-type of studies in the field of fear conditioning research andtheir extension to other outcome measures as well as data and design multiverse analyseswill aid the development of formal theories through the accumulation of empirical evidence.This may contribute to facilitated and more successful clinical translation.