The purpose of this project is to establish the range of effect sizes for the correlation between hippocampal volume and navigation ability. Many studies have been conducted on this question, many of which show a relationship between some aspect of navigation behavior and some aspect of the structure of the hippocampus. Unfortunately, existing studies have all made different (and reasonable) decisions about factors to include as covariates (total brain volume, age, gender, etc.), as well as which specific hippocampal structure is used (e.g., posterior vs. anterior, right vs. left vs. combined). In addition, many studies use voxel based morphometry, a technique which does not allow precise estimation of effect sizes if not accompanied by volumetry statistics. For that reason, the purpose of this project is to collect the original structural images from these studies, along with the relevant navigational measures. Once collected, these data can be re-analyzed with and without covariates, and across all possible partitions of hippocampal (and other subcortical) structures. We realize that this method is subject to publication bias, and even multiple comparison issues within individual studies (e.g., original authors can send the behavioral variable that correlated with volume, even if others did not (although we will discourage this and attempt to attain multiple relevant behavior measures where possible)). But the purpose of this reanalysis is not to determine publication bias, or gather a highly accurate measure of effect size. Rather, the purpose is to identify how analysis choices affect the correlation between brain structure and behavior, and to determine whether certain aspects of structure (e.g., posterior/anterior, right/left) correlate more or less strongly with behavior. The existing state of the literature makes this an impossible task at the moment. This OSF project will ultimately contain the processed data, links to the original raw data (with permission from the original authors), and all code used to analyze and process the data.