Marcy and Jack take on a two thousand ten pilot study — ten combat veterans, four weeks of HRV biofeedback, sharper attention, and the honesty caveats that keep the science honest — plus a two-minute settle-the-snow-globe morning practice. Read the paper: Cardiac Coherence and Posttraumatic Stress Disorder in Combat Veterans (Ginsberg, Berry, Powell, 2010, Alternative Therapies in Health and Medicine) — https://www.heartmath.org/research/research-library/basic/improving-cognition-in-recently-returned-combat-veterans/