Researchers at HHMI’s Janelia Research Campus have made a groundbreaking discovery that suggests animals possess the ability to imagine. A team from the Lee and Harris labs combined virtual reality and a brain-machine interface to investigate a rat’s inner thoughts.
Their findings indicate that animals, much like humans, can engage in mental processes involving places and objects that are not physically present. They can imagine scenarios like walking to a distant location or moving an object to a specific spot.
Similar to humans, rodents exhibit specific neural activity patterns in their hippocampus, a region responsible for spatial memory, when experiencing places and events. This new research demonstrates that rats can voluntarily generate these same patterns, even when recalling locations far from their current position.
This ability to imagine locations removed from their current surroundings is crucial for remembering past events and envisioning potential future situations. Consequently, the study’s authors conclude that animals, like humans, possess a form of imagination.
Examination of the Hippocampus
The researchers created a real-time “thought detector” using a brain-machine interface that connects brain activity to an external device. Their system linked the electrical activity in the rat’s hippocampus to its position in a 360-degree virtual reality arena.
The hippocampus stores mental maps related to memory recall and future scenario imagination. The team wanted to determine if animals could consciously control this activity, which the brain-machine interface allowed them to investigate.
To decode the rat’s brain signals, the researchers developed a “thought dictionary” that compiled activity patterns associated with specific places in the virtual reality arena. The rat was harnessed in a virtual reality system where its movements on a spherical treadmill were translated onto a 360-degree screen. The rat received rewards for reaching its goals, and the brain-machine interface recorded hippocampal activity.
In one task, named “Jumper,” the treadmill was disconnected, and the rat had to reproduce the hippocampal activity pattern associated with a goal location to receive a reward. In the “Jedi” task, the rat used its thoughts to move an object to a location in the virtual reality space. This demonstrated the rat’s ability to control its hippocampal activity and adapt to changes in goal location.
The results showed that rats could precisely and flexibly control their hippocampal activity, similar to how humans might engage in mental navigation. They could maintain their focus on a specific location for a considerable duration, akin to how humans recall past events or imagine future scenarios.
This study not only reveals the existence of animal imagination but also provides a novel method for studying the hippocampus using brain-machine interfaces. Furthermore, it opens up the possibility of developing prosthetic devices based on similar principles, as brain-machine interfaces are increasingly used in prosthetics.
References:
Source of the article: Rats have an imagination, new research finds. Rats have an imagination, new research finds. https://phys.org/news/2023-11-rats.html
Source of the research paper: 1. Lai C, Tanaka S, Harris TD, Lee AK. Volitional activation of remote place representations with a hippocampal brain–machine interface. Science. American Association for the Advancement of Science (AAAS); 2023 Nov 3;382(6670):566–573. http://dx.doi.org/10.1126/science.adh5206
Leave a Reply