What problem does it solve? Running BrainGNN for fMRI-based phenotype prediction requires careful handling of graph construction, Fisher-z connectivity transforms, and PyTorch Geometric compatibility, which this Skill codifies into a reproducible training and evaluation workflow. ## Core Features & Use Cases - Graph construction and training: Builds full ROI-level graphs from per-subject .pt connectivity files and trains BrainGNN with K-fold cross-validation for classification or regression. - Multi-model benchmarking: Scripts compare BrainGNN against BNT, BrainNetCNN, LGGNN, IBGNN, and ComBrainTF across multiple atlases on lifespan age regression. - Hypothesis-driven validation: Maps knowledge-graph hypotheses to HCP phenotype labels and AAL-116 ROI masks for region-guided subgraph training and edge boosting. - Use Case: A researcher with preprocessed HCP fMRI data trains BrainGNN on the Schaefer-100 atlas to predict gender, then sweeps atlases to compare accuracy and inspect interpretable pooling scores. ## Quick Start Ask the agent to train BrainGNN on the aal_116 atlas with the HCP gender labels CSV using 5-fold cross-validation and report test accuracy.