power contours

power contours visualizes statistical power across combinations of trial numbers and participant counts to guide experimental design decisions in psychology and neuroscience.

Key Features:

• Statistical Power Visualization: Generates two-dimensional iso-power contour plots that map statistical power as a function of numbers of trials and participants.
• Variance Analysis: Quantifies the influence of within-participant variance relative to between-participant variance and identifies when increasing trial numbers substantially affects power.
• Application Across Paradigms: Validated using datasets from eight experimental paradigms, including reaction times, sensory thresholds, fMRI, MEG, and EEG.
• Practical Implementation: Provides example code to estimate within- and between-participant variance for each method to inform study design.

Scientific Applications:

• Study Design Optimization: Optimize numbers of trials and participants to achieve target statistical power while minimizing resource use in behavioral and neuroimaging experiments.
• Modality-Specific Power Assessment: Assess detectability of effects in paradigms such as reaction times, sensory thresholds, fMRI, MEG, and EEG by accounting for trial-level and participant-level variance.
• Reproducibility and Resource Allocation: Inform reproducible experimental configurations by balancing trial counts and sample sizes based on observed variance structure.

Methodology:

Computes two-dimensional iso-power contour plots from estimates of within- and between-participant variance derived from empirical datasets, with validation using datasets from eight paradigms including reaction times, sensory thresholds, fMRI, MEG, and EEG.