The Pentagon is funding studies in three Army hospitals. The procedure is called a stellate ganglion block. Doctors say it essentially blocks the ‘fight-or-flight’ reaction that causes stress to the brain. Psychologist Dr. Carrie Elk has treated several veterans who’ve had the procedure. “Sometimes it doesn’t work and they don’t have an effect, but for those that do have an effect, they say it’s very positive and immediate at relieving their symptoms, but temporarily,” said Elk, who wants to see more research.