Redefining Reality - The Intellectual Implications of Modern Science

Scientists at MIT have taken DNA from animals whose cells are
photosensory—that is, cells that turn light it into electricity—and
spliced it into neurons in mice. The researchers could then trigger
memories, because the light shone into the brain would trigger
those and only those photosensory cells.
The researchers could have a mouse experience something in a
certain context, say, getting a painful shock immediately after
it sees the red light and exhibits behaviors associated with fear. But
by getting the right neurons to be photosensitive, researchers could
with no fear response. The mouse forgets the shock it experienced.
Similarly, and perhaps more frighteningly, researchers have been
able to implant a memory in a mouse’s brain.
Mice were created with certain neurons that could be activated
with light signals. These optogenetic mice were put into a
black room and allowed to explore. They behaved normally
and roamed throughout the room. Then, the mice were put in
a red room, where they were given a shock. This created the
conditioning that led them to be afraid of the red room when
placed there.
The mice were later placed back in the black room. Again,
they behaved normally until the neurons associated with the
conditioned fear response to the red room were activated.
Then, the mice behaved exactly as they did in the red room,
with a conditioned fear response.
The researchers had created in these mice a false memory of
having been shocked in the black room, which caused them to
behave exactly as they do with authentic memories.
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