The research team of Professor Woo Choong-wan of the Department of Global Biomedical Engineering at Sungkyunkwan University (SKKU) investigated changes in brain networks when people are in persistent pain through functional magnetic resonance imaging (fMRI). Pain often comes from a noxious stimulus, but is ultimately influenced by various factors such as emotion, belief, and memories. A complex interaction between these factors becomes more important in the revelation and deterioration of pain when it is continuous. How these factors interact with the brain and how the brain changes according to such factors was previously unknown. However, Prof. Woo’s research team discovered changing patterns of functional brain networks through an fMRI experiment while the subjects felt pain due to capsaicin for about 20 minutes. At first, the somatosensory brain network related to brain areas appeared widely across the brain, but as time passed, its connection with the cerebellum and other regions increased. The machine learning model which learned the patterns could discern the existence and nonexistence of consistent pain and successfully predict the strength of pain. Prof. Woo said, “This study supports the hypothesis that pain can be defined as the brain’s actively responding process against the stimulus. The research will provide important clues for understanding chronic pain.”