Our experience of time doesn’t always match the perfect ticking of a clock. As the famous quote (often attributed to Einstein) goes: “Sit on a hot stove for a minute, and it seems like an hour. Sit with a pretty girl for an hour, and it seems like a minute.”
Scientists at the Kavli Institute for Systems Neuroscience (NTNU) in Norway have now discovered the network of brain cells, called the enigmatic lateral entorhinal cortex (LEC), that deals directly with this subjective experience of time. The research is a giant leap forward in our understanding of the experience of time, especially how it distorts and morphs with our memory, as reported today in the journal Nature.
"This network provides timestamps for events and keeps track of the order of events within an experience," Professor Edvard Moser, Nobel laureate and director of the Kavli Institute at the NTNU, said in a statement.
Humans and other creatures have multiple different “biological clocks” ticking away in their bodies to measure different bodily functions, most notably our 24-hour circadian rhythm that tells us when to sleep or the 10-second clock in our hippocampal cells. The new research identifies a very specific “neural clock” that works like a “strong time-coding signal deep inside the brain” to record our experiences, the chain of events, and our memories.
“Our study reveals how the brain makes sense of time as an event is experienced," explains lead author Albert Tsao. "The network does not explicitly encode time. What we measure is rather a subjective time derived from the ongoing flow of experience."
To reach this finding, scientists analyzed the brains of rats while they performed different tasks. First, they were free to run around and chase bits of chocolate. In the second part, they were given the hard task of chasing chocolate while turning round and round in an eight-shaped maze.
The two activities saw a massive difference in the time-coding signals of the LEC, the time-measuring network. For the stimulating “fun” first task, the rat appeared to have a good record of time and idea about the sequence of events. In the second part, the activity of the LEC was steady and predictable, yet also repetitive and overlapping
“The data suggest that the rat had a refined understanding of temporality during each lap, but a poor understanding of time from lap to lap and from the start to end throughout the experiment," added Tsao.
As the researchers explain, this shows that our activities (aka the content of your experience) can actually change the course of the time-signal in LEC and distort the way you perceive time. Trippy.
