2018/05/30 by Benjamin O. Turner, Erick J. Paul, Michael B. Miller +1 · 2 citations
Neuroscience · Medicine · Psychology · Mathematics · #Functional Brain Connectivity Studies #Advanced MRI Techniques and Applications #Neural and Behavioral Psychology Studies #Sample size determination #Sample (material) #Statistical power #Task (project management) #Functional magnetic resonance imaging #Computer science #Psychology #Large sample #Statistical hypothesis testing #Artificial intelligence #Statistics #Cognitive psychology #Mathematics #Neuroscience
paper · pdf · doi:10.1038/s42003-018-0073-z
openalex publication_date 2018/05/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
Abstract Despite a growing body of research suggesting that task-based functional magnetic resonance imaging (fMRI) studies often suffer from a lack of statistical power due to too-small samples, the proliferation of such underpowered studies continues unabated. Using large independent samples across eleven tasks, we demonstrate the impact of sample size on replicability, assessed at different levels of analysis relevant to fMRI researchers. We find that the degree of replicability for typical sample sizes is modest and that sample sizes much larger than typical (e.g., N = 100) produce results that fall well short of perfectly replicable. Thus, our results join the existing line of work advocating for larger sample sizes. Moreover, because we test sample sizes over a fairly large range and use intuitive metrics of replicability, our hope is that our results are more understandable and convincing to researchers who may have found previous results advocating for larger samples inaccessible.