Scientists probe into a rat’s inner thoughts, find imagination
A team from HHMI’s Janelia Research Campus has managed to peer into a rat’s inner thoughts by inventing a unique technology that combines a virtual reality arena with a brain-machine interface. What they found is a thought process very similar to that of humans.
The researchers were able to determine that the hippocampus, a part of the brain vital for the formation of new memories, particularly declarative or explicit memories, exhibited distinct neural activity patterns in rats when they tried to recollect locations and events. This activity is also present in humans.
Activating the representation of location
“The rat can indeed activate the representation of places in the environment without going there,” said Chongxi Lai, a postdoc in the Harris and Lee Labs and first author of a paper describing the new findings. “Even if his physical body is fixed, his spatial thoughts can go to a very remote location.”
How did the team of researchers come to this conclusion?
The scientists created a real-time “thought detector” that could measure brain activity and interpret it in order to comprehend what the animals were thinking when trying to navigate their way through a 360-degree virtual reality arena.
The brain-machine interface (BMI) that the researchers used allowed the rats’ brain activity to be directly connected and reported to an external device. It was therefore able to transmit the rat’s observed hippocampal electrical activity while the animal thought of its location in the virtual reality arena.
The hippocampus helps consolidate short-term memories into long-term memories by encoding and storing information about facts and events. It is also involved in spatial learning and navigation. It helps humans create cognitive maps of their environment, allowing them to remember locations and navigate through space. However, it was previously unknown if animals could choose to control this part of the brain when trying to remember a location.
By using the BMI, the researchers were able to determine whether a rat can trigger the hippocampus simply by thinking about a spot in the arena rather than physically visiting it. In other words, they sought to determine whether the animal could imagine the location.
Much like humans
The researchers discovered that, just like people, rats have control over their hippocampus activity, allowing them to focus their thoughts for extended periods of time on a specific spot, much like people do when they daydream or replay previous experiences.
“To imagine is one of the remarkable things that humans can do. Now we have found that animals can do it too, and we found a way to study it,” says Albert Lee, formerly a Group Leader at Janelia and now an HHMI Investigator at Beth Israel Deaconess Medical Center.
Additionally, the study demonstrates that BMI may be used to measure hippocampus activity, offering a fresh method for researching this crucial area of the brain. This new work opens up the possibility of creating innovative prosthetic devices by learning how to control inner thoughts instead of just probing into them.
Source: Interesting Engineering
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Scientists probe into a rat’s inner thoughts, find imagination