Rats can use imagination to mentally recreate places they’ve visited
If a rat has walked through a location before, it can imagine that place, with the help of virtual reality. Some now expect all mammals to be capable of such thoughts
By Jason Arunn Murugesu
2 November 2023
With virtual reality, and the promise of a sugary reward, rats can be made to use their imagination
SolStock/iStockphoto/Getty Images
Just like someone may look back on a treasured holiday, wishing they were still there, rats can also imagine being in places they’ve visited before.
A region of the brain called the hippocampus, which plays a big role in memory, is very consistent across mammals. This led scientists to suspect that non-human animals are similarly capable of imagining places they have been to before, but it is difficult to prove that such a brain process occurs. “You can’t talk to animals and ask them to imagine something,” says Albert Lee at the Beth Israel Deaconess Medical Center in Boston, Massachusetts.
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He and his colleagues hoped that advances in technology could overcome this by creating an interface between the animals’ brains and a machine, allowing them to communicate.
To put the idea to the test, the researchers devised a 360-degree virtual reality (VR) arena. They had three rats walk on a treadmill within this, but the VR made it look to the animal like it was moving through a space resembling a dark tunnel.
The rats were trained to find certain shapes within the VR for a reward of sugary water. While they looked for these shapes, electrical signals were recorded from their hippocampus. The researchers used this data to produce a brain-machine interface that reverse engineered the signals produced by the rats into images that were then displayed in the VR arena.
