Anyone who wakes up in a hotel room and for a moment does not recognise their environment knows about the phenomenon of brief memory lapses.

On the basis of research into rats, Norwegian researchers have now put forward the theory that memories come in tiny packages, each of which is 125 milliseconds in length. Writing in the scientific journal Nature, Professors Edvard and May-Britt Moser suggest that the hotel room package gets delayed, whereas we normally do not notice the transition from one memory to the next.

“When you feel a little confused, it is because there is a competition in your brain between two memories. Or maybe more than two,” May-Britt of the University for Science and Technology in Trondheim, Norway said.

Usually the processes are much too rapid for us to become aware of the switch from one memory to the next. The researchers believe the brain can in general switch memory packages up to eight times a second.

The neuroscientists studied electrical activity in the brains of rats, after the subject rats had learned in a drawn-out process that a particular lighting scheme represented a particular room. By means of this trick the rats could be “teleported” from one room to the next, as the scientists expressed it.

They could then observe certain activity patterns in the brain cell corresponding to each lighting system. “When we switch to another lighting system, the pattern is completely different,” May-Britt Moser said. She concluded that the brain jumps between tiny packages of memories.

Although the observations were made using rats, the research team believes they can be extrapolated to humans. “The rats are just as disoriented as we are,” May-Britt Moser said. “We are beginning to get a glimpse of the contours of the mechanisms that make up the world of our thoughts.”

Keywords: neuroscience

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