Does the motor system functionally contribute to keeping words in working memory? A pre-registered replication of Shebani and Pulvermüller (2013, Cortex)

Increasing evidence implicates the sensorimotor systems with high-level cognition, but the extent to which these systems play a functional role remains debated. Using an elegant design, Shebani and Pulvermüller (2013) reported that carrying out a demanding rhythmic task with the hands led to selective impairment of working memory for hand-related words (e.g., clap), while carrying out the same task with the feet led to selective memory impairment for foot-related words (e.g., kick). This striking double dissociation constitutes strong evidence for an embodied account of working memory, a system that has received scarce attention in the embodiment literature. However, the original study was likely underpowered and used suboptimal statistical analyses, raising questions about the robustness of the results. In fact, our Bayesian reanalysis with a more appropriate model yields inconclusive evidence for the effect (BF10 = 1.7). To re-examine this seminal finding, we here attempt an appropriately powered, fully pre-registered replication of the original study, following a sequential design with a maximal participant sample size over seven times that of the original (108 vs. 15). We will analyse the results with Bayesian generalized mixed models and use Bayes factors to quantify the evidence in support of the effect predicted by theories of embodied cognition.