New research, based on earlier results in mice, suggests that our brains are never at rest, even when we are not learning anything about the world around us.

Our brains are often likened to computers, with learned skills and memories stored in the activity patterns of billions of nerve cells. However, new research shows that memories of specific events and experiences may never settle down. Instead, the activity patterns that store information can continually change, even when we are not learning anything new.

Why does this not cause the brain to forget what it has learned? The study, from the University of Cambridge, Harvard Medical School and Stanford University, reveals how the brain can reliably access stored information despite drastic changes in the brain signals that represent it.