Humans are the only known living species that have a sense of time. Let’s take a second to think about that. We have such complex time systems. Seconds, minutes, hours, days, weeks, months, years, decades, centuries, millennia, eras. It’s amazing how our brains are able to understand this concept. What’s even more impressive is the ability of our brains to be able to track elapsed time. If that weren’t possible, we would be doing all of the little things we do for indefinite amounts of time. I bet that if you had to guess, you’d guess that reading to this point of the article would have taken you around 30 seconds. See what I mean?
But how does the brain have and maintain such a finely tuned internal clock? Neuroscientists believe that we have distinct nerve systems that support the many different types of time processing. Until just recently, it has been theorized this was all under the confines of a single brain system. Recent research proves that theory might be a little too simple.
The research conducted and published in the Journal of Neuroscience showed that the brain might actually contain a second clock for tracking time. Furthermore, both internal clocks might be even competing with each other.
Former studies suggested that the striatrium in the brain, used for temporal information, may indeed be where the central clock was located. This was due to people who had Parkinson’s disease, where the same part of the brain were affected, had also trouble telling time. However, the new research proposes that there is a second internal clock located in the hippocampus. The hippocampus is utilized by the brain to remember past experiences, and is now being speculated to have a hand in remembering the passage of short time intervals.
The study proved this experimented on rats, and whether or not they were able to discern time differences with a chemical injected into them that temporarily inactivates the hippocampus. This allowed the researchers to test whether the hippocampus was actually functionally used to tell time, as suggested in their research. The results showed that while the hippocampus does help track elapsed time, it has a very particular and specific way of doing this. It only differentiates time differences between similar time periods at long time scales – on minutes. If we’re talking about different time scales, another part of the brain’s timekeeping system is doing this.
In layman terms, the hippocampus may not take not of things happening second by second, but it does recognize and track the massage of these moments. So when you make it on time to a meeting, or drive through traffic going to an appointment, don’t forget how complex and mind-numbingly complicated your brain works just so you can keep track of time!