New research on rats suggests that while they sleep, they dream of how to accomplish tasks— most specifically, those related to food.
In the study, scientists monitored the brain activity of rats during three specific tests. The rats were first monitored while viewing food in a location they could not reach; next while they were resting in a chamber separate from the food; and finally, the rats were examined once allowed access to the food as they walked to it.
One of the researchers, Hugo Spiers, indicated in a UCL news release that “during exploration mammals rapidly form a map of the environment in their hippocampus” and that “during sleep or rest, the hippocampus replays journeys.”
During exploration, mammals rapidly form a map of the environment in their hippocampus. During sleep or rest, the hippocampus replays journeys through this map which may help strengthen the memory. It has been speculated that such replay might form the content of dreams. Whether or not rats experience this brain activity as dreams sis still unclear, as we would need to ask them to be sure! Our new results show that during rest the hippocampus also constructs fragments of a future yet to happen. Because the rat and human hippocampus are similar, this may explain why patients with damage to their hippocampus struggle to imagine future events.
According to the Christian Science Monitor, the researchers found that the brain cells used for navigation were showing the same activity when the rats were resting and when they were traveling to and from the food. These findings indicate that the rodents’ brains were hard at work planning paths to their food while they rested.
While the study did not conclusively find that rats dream of these planned paths to their goals, it suggests that humans are not the only mammals to imagine future events or plan ways to achieve their goals. As to whether the rats replay their plans in the dreams, as Spiers said, “You can’t ask rats what they’re thinking or dreaming.”
In other rodent related news, Immortal News reported on blind rats who, once equipped with geomagnetic compasses and microstimulators, showed the ability to navigate a maze as well as rats with normal vision.
