The fMRI scan revealed increased activity in the left hemisphere of Padgett’s brain, which is where mathematical skills are thought to originate. Another area in Padgett’s brain that lit up was the left parietal cortex, a region responsible for integrating information coming from different senses. Brogaard’s team also used a transcranial magnetic stimulation (TMS) as a way to pinpoint the exact location of Padgett’s synesthesia. The TMS involves directing a magnetic pulse at a desired part of the brain, which either activates or inhibits a specific region. The results of the TMS experiment showed that when zapping Padgett’s parietal cortex, his synesthesia could be turned on and off.