In a groundbreaking study that could have enormous impacts for people suffering from amnesia and other types of brain trauma, doctors have demonstrated a way to “retrieve” forgotten memories. According to the Washington Post, researchers were able to reactivate suppressed memories in mice, suggesting that amnesia affects the brain’s ability to retrieve memories more than its ability to restore them.

Using advanced imaging technology, researchers were able to follow the entire process a mouse took when it made a memory. By picking out specific neurons and using a special protein delivered by a virus, scientists were able to make the neurons sensitive to blue light. Shining the blue light on a neuron effectively turned it on and off, like a switch.

The researchers identified which neurons were stimulated when a mouse formed a memory by giving the rodent a small electric shock. When the mouse returned to the location where it received the shock, it froze up, indicating that it remembered. The team used the light-sensitive technology to test whether or not they could erase and then bring back one specific memory.

By blocking the pathways to memory formation with a drug called anisomycin, the scientists were able to make the mice forget that they had received shocks. When they shined blue light on the sensitized neurons, the mice appeared to remember and exhibit fear of the shock chamber.

The study’s findings have serious implications for the way we understand memories and people suffering from memory loss. The research suggests that lost memories aren’t actually lost, and that an engram remains even though a person may not be able to recall a specific memory. Though doctors won’t be shining blue light on peoples’ heads to make them remember their childhoods anytime soon, the research has a wide range of implications for the way we treat brain trauma and amnesia.