14 DAY TRIAL // The hippocampus is a brain region related to a lot of functions connected to the human body, including to the memories.
A recent study led by neuroscientist Eleanor Maguire from University College London showed that the lesion of the hippocampus does not only impair memory formation, but also imagining the future, based on previous experience.
The team assessed this by investigating 5 amnesiacs and 10 control subjects with healthy hippocampi. The subjects were put to describe a range of imaginative common actions, like visiting a museum. Healthy people could describe everything, from the exhibited paintings to the smell of the old building.
The amnesiac subjects counted something very different. They were worse at imagining future events; their visualizations of future events were disorganized and emotionless. This is what one patient said. "There's big doors. The openings would be high, so the doors would be very big with brass handles, the ceilings would be made of glass, so there's plenty of light coming through. Huge room, exit on either side of the room, there's a pathway and map through the center and on either side there'd be exhibits." He paused. "I don't know what they are. There'd be people." He paused again.
"To be honest, there's not a lot coming."
"Do you hear or smell anything?" asked the investigators.
"No, it's not very real. It's just not happening. My imagination isn't well, I'm not imagining it, let's put it that way. Normally you can picture it, can't you? I'm not picturing anything at the moment."
Even when given pictures, sounds and smells to help them, amnesiacs could not provide any better description. "It seems that not only do they have a deficit in recollecting the past, they also have a deficit in imagining the future, so they really are stuck in the present," Maguire says.
"The details are not being hung together in the correct way, because it lacks a spatial backdrop."
"They felt like they weren't seeing it correctly or seeing it as a whole," Maguire says.
Thus, the hippocampus not only helps in constructing memories, but also in foreseeing the future, creating imagines of what is going to be. "The actual function of memory is maybe to help us plan for the future and work through various scenarios,"
"Now we are working on what other sorts of tasks might use the processes we've uncovered here that might not have much to do with memory", said Maguire.
"Being able to remember past events and being able to plan for the future go hand in hand", says psychologist Thomas Zentall at the University of Kentucky in Lexington, Kentucky, US.
"Presumably memory has evolved because it has a benefit."