Ever since Men in Black introduced us to the concept of the "neuralyzer", we've longed for a pen-shaped gadget capable of erasing memories with a flash of light. So many drunken rants erased, never ending opportunities to rewatch a film for the first time. Finally, 17 years on (let that sink in a moment), scientists have taken a tentative step toward making the neuralyzer a reality.
Researchers at the Davis Center for Neuroscience and Department of Psychology at the University of California have used light to erase specific memories in mice, proving a basic theory of how different parts of the brain work together to retrieve memories. But there are some vital differences between the red blink of the neuralyzer and the techniques used by the researchers.
Foremost is that the mice used were genetically modified: when their nerve cells were activated, they glowed green and expressed a protein that allowed the cells to be switched off by light. This allowed the researchers to follow exactly which nerve cells in two sections of the brain - the cortex and hippocampus - were activated in learning and memory retrieval, and switch them off with light directed through a fibre-optic cable.
To test out the theory that episodic memories involve coordinated activity between the cortex and hippocampus, the researches placed them in a section of a cage that would deliver a mild electric shock. The mice would then stay well clear of this section, proving they had a memory of the discomfort it caused them, with the relevant nerve cells glowing green to show learning. These cells were then turned off with light via a fibre-optic cable, resulting in the mice seemingly forgetting about the shocks and wondering about their cage with no sign of fear.
So, scientists can interfere with your memories using fibre-optics. You just need a genetically modified brain in order to forget about that drunken conversation you had with your ex at 3am last Friday.