Todd Braver emerges from a tent nestled against the canyon wall. He has a slight tan, except for a slim pale band around his wrist.
For the first time in three days in the wilderness, Mr. Braver is not wearing his watch. “I forgot,” he says.
It is a small thing, the kind of change many vacationers notice in themselves as they unwind and lose track of time. But for Mr. Braver and his companions, these moments lead to a question: What is happening to our brains?
Mr. Braver, a psychology professor at Washington University in St. Louis, was one of five neuroscientists on an unusual journey. They spent a week in late May in this remote area of southern Utah, rafting the San Juan River, camping on the soft banks and hiking the tributary canyons.