- Click to share on Facebook (Opens in a new window)
- Click to share on Twitter (Opens in a new window)
- Click to share on LinkedIn (Opens in a new window)
- Click to email a friend (Opens in a new window)
Editor's Note: Daphna Shohamy is a neuroscientist at the Zuckerman Institute at Columbia University and the Department of Psychology. The opinions expressed here are his. Read more opinion at CNNe.com/opinion
(CNN) - The other night, as I was trying to decide what to do for dinner, I froze. Should I make lentils or pasta? I tried to remember which one would last the longest. Can I remember what was still in stock on my supermarket shelves? Had you decided when to make your next grocery purchase?
In a world reeling from the coronavirus pandemic, mundane decisions can feel as difficult as existential ones. The real problem is not about something as minor as a food choice, but about understanding how, as so many decisions are taken from us, we can feel paralyzed in front of those that we still have to make. Your brain does not distinguish between consequential and trivial decisions now. The line between them is blurred by uncertainty.
In my job as a neuroscientist I try to shed light on what happens in our brains when we deliberate. We design laboratory experiments that challenge the decision-making process and test how the brain responds to these challenges. And while our research can't tell you what decision to make, it helps reveal why it's so difficult for many of us to make any decision, big or small, right now.
- Why is it so difficult to make decisions at age 20? The answer is in the brain (2015)
The answer is in how our brain uses memory. When faced with a decision, our brain calculates the possible results to help us make the best decision. This estimate is based on past experience. It's easy to decide what coffee to order at our favorite location because we've ordered it many times before. We make many of our other daily decisions on the same basis. The brain learns by experience what works best.
So what happens when faced with decisions in a context that is very different from anything that has been experienced? Does memory play a role when everything is changing and everything is uncertain, when there is no clear pattern of past choices to learn?
Yes. In fact, memory is especially important for making decisions in the face of great uncertainty. It is crucial for our survival and prosperity. This is because memory is not only a record of the past, but also the basis of our ability to imagine the future.
The part of the brain needed to create memories is the hippocampus, a seahorse-shaped structure located just behind our ears. People with hippocampal damage cannot create new memories. Nor can they vividly imagine events that may happen to them in the future. And since they cannot imagine the future, they also struggle to make simple decisions in the present.
In a recent study, we looked at people's brains as they made minor decisions between two snacks, weighing between potato chips and pretzels or Kit Kat versus M & M's. The more people deliberated, the more they activated the hippocampus. People with hippocampal damage took more than twice as long to make these seemingly simple decisions.
This deep anatomical connection between making memories and imagining the future indicates that the brain does not respect the limits of time. Without an anchor to the past, fight to build bridges to the future.
- This morning exercise routine is also good for your brain
Memory is not just a record of something that happened. It is a creative, temporarily transcendent device that helps us generate plausible versions of what is to come. You may not be aware of this on a conscious level, but this is how our brain routinely handles simple and complex decisions.
If your brain relies on memory for decision-making, should you worry that you're flying blindly, while your brain struggles in vain to forecast an unpredictable future? Or is their effort a sign that your brain is on the right track, even when mental work can give you a temporary headache?
The answer is both. Without access to reliable evidence from the past, your brain uses what it can to project into the future. Don't just guess. In situations of great uncertainty, the brain uses the most easily accessible information, however flawed it may be. But if you understand the power of memory in shaping your decisions, you can exercise some control over it. You can slow down and make sure you're using the most relevant memories for the future you want.
For example, New Yorkers experiencing the coronavirus pandemic may recall the fears we feel after the attacks of September 11, 2001. However, when the darkness of September 11 is recalled, one can also remember incredible solidarity; the expression of support that kept the communities intact. You may recall how our worst fears of what might come did not come true.
A memory like this can help you decide that you don't really need to risk going to the supermarket; that it is much more important to put our efforts and thoughts to help our most vulnerable neighbors, friends and family.
Also, the sense of effort that comes with decisions is not in itself something to worry about. Effort is just a sign that your brain is doing its job, trying to gather as much information as possible to help you make good decisions for your survival. At times like these, where the divide between life before and after the new coronavirus seems so vast, the evidence it gathers is naturally uncertain, so your brain keeps looking for more.
Suddenly, each decision involves considering a new set of factors and dimensions that seem to be constantly changing. This search for information occurs unconsciously, but it is laborious and time consuming, which lends itself to that frenetic feeling that we have all experienced in the past few weeks.
Millions of years of evolution have given your brain the ability to make decisions when things are uncertain. In fact, this is how your brain makes decisions all the time. It can be puzzling to recognize the amount of future information that your decisions involve. But even when faced with a reality that is very different from anything we've experienced before, the hippocampus can rise to the occasion, uniting the past with the future.
This takes time and effort, but it's helpful to know that your brain has a lot of experience doing just that.
coronavirus