The mind has muscles. Just like physical strength, mental strength can be strengthened by systematic and repeated training. In his new book, Inner Communication, Dr. Joo-Hwan Kim, who has been focusing on the study of mental strength since the publication of his bestselling book Resilience, reveals the most effective ways to build mental strength. To prove the efficacy of Inner Communication Meditation, he conducted joint research with leading Korean neuroscientists and mental health specialists, and verified his findings in the field.