Call it Total Recall for mice. In two new studies, researchers have found a way to stimulate the brains of rodents to activate a specific memory trace. This advance could help explain how we form our own memories, and why competing recollections sometimes make it hard to learn new information.

In recent years, neuroscientists have devised several ways to erase memories in rodents. The new studies take steps in a different direction, using the latest genetic and other tools to activate specific memories on command.