In a new study, investigators from McLean Hospital, Harvard Medical School and the National Institute on Drug Abuse—Intramural Research Program (NIDA-IRP) have discovered that the tendency of people’s arousal to wane over the course of brain scans has been distorting the brain connection maps produced by functional magnetic resonance imaging (fMRI). The team found that as people’s arousal levels dwindle during an fMRI, such as if they become more relaxed and sleepy, changes in breathing and heart rates alter blood oxygen levels in the brain—which are then falsely detected on Read More