Today’s Been a Heck of a Week!

Around Wednesday of each week, I’ve found myself gobsmacked that it’s only Wednesday. How could there still be half the week left when it feels like this week has already lasted so long? And it extends to the longer timescales too. These last few months have felt like years. How is it only April? I know I’m not alone in feeling this. It seems every day I see a different version of the 30 Rock or grizzled captain memes. You know the ones: “It’s been a hell of a week.” “Uh, Captain, it’s only Wednesday!” How are we all experiencing a disconnect between our own sense of time passing and how much time has actually passed? It’s like some sort of collective temporal illusion.

Why is this happening to us all? The best explanation for this psychological phenomenon comes from basic neuroscience research. The short answer is our brains track time by counting experiences, and each day lately has been filled with a barrage of shattering news briefs. Each new attack on our systems, each new mass firing of federal officials, each new volley in the trade war, each office/institute/department closed, each new stock market drop, each new assault on our rights, each new kidnapping — all of them are different experiences in our brains. Each one is a different, new experience, and each experience keeps telling our brains that time is moving forward, but then we look at our calendars and see that time is still going at its normal pace. There’s a serious disconnect there.

To understand the science behind this phenomenon, work by my lab and others has begun to provide insight. It’s been found that the more experiences we have in a period of time, the more the clock moves forward. My lab found evidence of such a clock in the anterior cingulate cortex (Wirt et al., 2024), while others have shown similar effects in the hippocampus (Khatib et al., 2023). What’s been found is best described as “drift,” where neural signals become less similar the more separated they are in time. But, it’s not time passing that drives the networks to drift, it’s individual experiences.

In our lab, we examined the activity of large groups of ACC neurons, or ensembles, while animals completed a repetitive task. Animals would complete over 200 trials in total, but some animals worked fast and some worked slow, just like humans. Interestingly, all animals worked at their own consistent paces, though. When we examined the ACC activity during each trial, we found that the brain states were changing as trials were accumulated. This was the drift. Next, we leveraged the fact that animals worked at different paces and used machine learning techniques. We were able to determine that the number of trials, and not clock time, was related to the drift. Thus, experiences, or trials, were moving the networks forward.

Such activity is very useful for creating a unique temporal context for each event. This is of great importance when performing a series of tasks that are similar but each still distinct. In the lab, we see this in working memory tests where subjects are shown an example object, then, after a delay, shown the example plus another object and told to choose which was the example. Unique brain states on each trial can help distinguish the example on one trial from the examples on previous trials. This is also thought to be important for autobiographical memory, helping to form distinct memories for multiple experiences that occur in the same physical context. Indeed, both the ACC and hippocampus are very important for working and autobiographical memory, and we think these drifting signals underlie these functions.

So, the good news is that our brains are working as they should. Our lives have natural rhythms or paces that we all get accustomed to. There’s a reason that certain months—I’m looking at you, September—seem to last forever. Lots of events usually happen in September, especially if you are in academia and have school-age kids. Interestingly, this phenomenon can also work backwards, with our brains telling us not much time has passed, because little has happened, but the calendar says otherwise. We all remember the six-month-long March of 2020, when the whole world stopped.

I don’t have a solution to this problem right now, but it might be a good idea to take some days, or weeks, off from the news. Maybe that would help time to move at its normal pace again.