NEW YORK (Dispatches) -- Neuroscientists have discovered a focal pathway in the brain that when electrically stimulated causes immediate laughter, followed by a sense of calm and happiness, even during awake brain surgery.

The behavioral effects of direct electrical stimulation of the cingulum bundle, a white matter tract in the brain, were confirmed in two other epilepsy patients undergoing diagnostic monitoring, according to neuroscientists at Emory University School of Medicine.
Emory neurosurgeons see the technique as a "potentially transformative" way to calm some patients during awake brain surgery, even for people who are not especially anxious. For optimal protection of critical brain functions during surgery, patients may need to be awake and not sedated, so that doctors can talk with them, assess their language skills, and detect impairments that may arise from resection.
"Even well-prepared patients may panic during awake surgery, which can be dangerous," says lead author Kelly Bijanki, PhD, assistant professor of neurosurgery. "This particular patient was especially prone to it because of moderate baseline anxiety. And upon waking from global anesthesia, she did indeed begin to panic. When we turned on her cingulum stimulation, she immediately reported feeling happy and relaxed, told jokes about her family, and was able to tolerate the awake procedure successfully."
Outside of use during awake surgery, understanding how cingulum bundle stimulation works could also inform efforts to better treat depression, anxiety disorders, or chronic pain via deep brain stimulation.