Sleep Spindle Density and Geomagnetic Activity Dataset — Sleep-EDF Cassette (1989–1991)

Analysis-ready dataset and reproducible analysis code for the study: "Geomagnetic Activity Predicts Sleep Spindle Density in Healthy Adults: Evidence for Environmental Electromagnetic Modulation of Thalamic Gating" (Malone, 2026, submitted to Chronobiology International). Contains: (1) sleepedf_kp_merged.csv — merged dataset of automated sleep spindle detection results and matched daily geomagnetic indices (Kp_mean, Kp_max, Ap_daily) for 68 polysomnographic recordings from 35 healthy adults in the Sleep-EDF Cassette dataset (PhysioNet, 1989–1991); (2) spindle_geo_analysis.py — full reproducible analysis pipeline implementing spindle detection (FIR bandpass 11–16 Hz, amplitude envelope, 1.5σ threshold) and all statistical analyses reported in the manuscript (Spearman correlations, lag analysis, dose-response, OLS confound control, night-by-night replication). Raw EEG data are openly available at PhysioNet (https://physionet.org/content/sleep-edfx/1.0.0/). Geomagnetic indices sourced from NOAA/GFZ public archives.