R code for a meta-analysis comparing invasive (iVNS) and transcutaneous (tVNS) vagus nerve stimulation effects on cognition. Analysis code accompanying a systematic review and meta-analysis of vagus nerve stimulation and cognition, comparing invasive (iVNS) and transcutaneous (tVNS) modalities. Scripts compute Hedges' g effect sizes and run omnibus random-effects models, per-measure analyses, meta-regression on study- and stimulation-level moderators, and publication-bias assessment.