A team of scientists was able to determine that rats dream about goals they hope to fulfill in the future.
According to Discovery Magazine, authors of a study published in the journal eLife recorded a group of rats' brain activity after showing them the location of a treat. In studying the rats' brains, the researchers found the animals created "mental maps" in their sleep of how they could get to the treat.
To track the rats' mental activity during sleep, the scientists had to insert tiny sensors and wires in their brains, an experiment that could never be approved with human subjects. But because of the study, the scientists hope to get a better idea of what happens when people dream about their aspirations.
"During exploration, mammals rapidly form a map of the environment in their hippocampus," study senior author Hugo Spiers, a physiologist at University College London (UCL), said in a press release. "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 is 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."
The process of mentally mapping a route to the treat took up eight percent of the rats' brain activity during sleep.
"What we don't know at the moment is what these neural simulations are actually for," study co-author Caswell Barry, a bioscientist at UCL, said in the release. "It seems possible this process is a way of evaluating the available options to determine which is the most likely to end in reward, thinking it through if you like. We don't know that for sure though and something we'd like to do in the future is try to establish a link between this apparent planning and what the animals do next."
