According to new research from The UCL Experimental Psychology, it has been discovered that rats dream of the location of their snacks and are able to locate them. The specialized brain cell activity which was discovered proved that during sleep or rest, the journey is played throughout the rats’ hippocampus. This is by making an internal map. Several doctors worked on this discovery and have found similar findings. As all things science related, they are still trying to come up with the direct answer to the entire study, but they are optimistic that this is a step forward into the future.
Senior author Dr Hugo Spiers from UCL Experimental Psychology, said, “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 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 animals had been placed individually on a straight track with a T-junction n front of them while experimenting on their behavior. The access to the junction and the left and right hand arms beyond it had been prevented by a transparent barrier. While one of the arms consisted of the food, the other was empty. The rats were put into sleep for an hour after they had been allowed to observe the food. Lastly after the removal of the barrier, the animals had been returned to the track and permitted to run across the junctions and on to the arms.
The data demonstrated that during their resting period the place cells would present an internal map of the food arm had actually been active, whereas the cells that represented the empty arm were not activated in this manner. This is a sign that the brain had been taking preparation for future trajectory that led to their desired goal.
Co-lead author Dr Freyja Ólafsdóttir (UCL Biosciences) explains, “What’s really interesting is that the hippocampus is normally thought of as being important for memory, with place cells storing details about locations you’ve visited. What’s surprising here is that we see the hippocampus planning for the future, actually rehearsing totally novel journeys that the animals need to take in order to reach the food.”
According to the results, the hippocampus maps routes that are yet to take place as well keeping a record of the ones that has already taken place, but only in the presence of a motivation cue like food. It is possible that the ability to imagine future is not for humans only.
Co-lead author Dr Caswell Barry from UCL Biosciences says, “What we don’t know at the moment is what these neural simulations are actually for. 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.”
The study has been published in the journal eLife.