Lentils or pasta? Why small decisions feel as tough as big ones in this time of crisis

Daphna Shohamy, PhD, is a neuroscientist at Columbia University's Zuckerman Institute and Department of Psychology. The opinions expressed here are her own. Read more opinion at CNN.

(CNN)The other night, while trying to decide what to make for dinner, I froze. Should I use the lentils -- or the pasta? I tried to recall which would last longer. Could I remember what was still in stock on my supermarket's shelves? Had I even decided when I would be making that next grocery run?

Daphna Shohamy
In a world reeling from the coronavirus pandemic, mundane decisions can feel as difficult as existential ones. The real issue isn't about something as minor as a meal choice, but about understanding how, as so many decisions are taken away from us, we can feel paralyzed in the face of those we still need to make. Your brain does not distinguish between consequential and trivial decisions now. The line between them is blurred by uncertainty.
In my work as a neuroscientist, I seek to shed light on what happens in our brains when we deliberate. We design lab experiments that challenge the decision-making process and test how the brain responds to these challenges. And while our research can't tell you which decision to make, it does help reveal why it's so challenging for many of us to make any decision -- big or small -- right now.
    The answer lies in how our brain uses memory. Faced with a decision, our brain estimates possible outcomes to help us make the best choice. This estimation is based on past experience. It's easy to decide which coffee to order at our favorite café because we have ordered it many times before. We make many of our other daily decisions on the same basis. The brain learns from experience what works best.
    So what happens when you are faced with decisions in a context that is vastly different from anything you've ever experienced? Does memory play a role when everything is changing and everything is uncertain -- when you don't have a clear pattern of past choices to learn from?
    Yes. In fact, memory is especially important for making decisions in the face of great uncertainty. It's crucial to our surviving -- and thriving. This is because memory is not only a record of the past, it is also the bedrock of our ability to imagine the future.
    The part of the brain necessary for creating memories is the hippocampus, a seahorse-shaped structure located just behind our ears. People with damage to the hippocampus are not able to create new memories. They also can't vividly imagine events that might happen to them in the future. And because they can't imagine the future, they also struggle to make simple decisions in the present.
    In a recent study, we looked at people's brains while they made minor choices between two snacks, weighing potato chips against pretzels, or Kit Kat versus M&M's. The more people deliberated, the more they activated the hippocampus. People with damage to the hippocampus took more than twice as long to make these seemingly simple decisions.
    This deep anatomical connection between forming memories and imagining the future indicates that the brain doesn't respect boundaries of time. Without an anchor to the past, it struggles to build bridges to the future.
    Memory is not just a record of something that happened. It is a creative, temporally transcendent device that helps us generate plausible versions of the yet-to-come. You might not be aware of this at the conscious level, but this is how our brain routinely deals with both simple and complex decisions.
    If your brain relies on memory for decisions, should you worry that you are flying blind, your brain straining vainly to predict an unpredictable future? Or is your effort a sign that your brain is on track, even as the mental toil might bring on a temporary headache or two?
    The answer is both. Without access to reliable evidence from the past, your brain uses what it can to project into the future. It doesn't just guess. In situations with great uncertainty, the brain turns to the most easily accessible information, faulty as it may be. But if you understand the power of memory in shaping your decisions, you can exert some control over it. You can slow down and make sure you are using the memories that are most relevant to the future you want.
    For example, New Yorkers responding to the coronavirus pandemic may draw on memories of the fear we felt after the attacks of 9/11. Yet when you remember the darkness of 9/11, you can also recall incredible solidarity; the outpouring of support that kept communities intact. You can recall how our worst fears of what might come did not become a reality.
    A memory like this may help you to decide that you don't actually need to risk a trip to the grocery store; that it's far more important to put one's efforts and thoughts towards helping our more vulnerable neighbors, friends and family members.
    Moreover, the sense of effort that comes with decisions is not itself anything to worry about. The effort is just a sign that your brain is doing its job, trying to gather as much information as it can to help you make good choices for your survival. In times like these -- where the divide between life before and after the new coronavirus seems so vast -- the evidence you gather is naturally uncertain, so your brain keeps searching for more.
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    Suddenly every decision involves consideration of a new set of factors and dimensions that seem to be constantly changing. This search for information happens unconsciously, but it is effortful and time-consuming -- lending to that frantic feeling we've all experienced in recent 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 solves decisions all the time. It can be unnerving to recognize how much future-telling goes into your decisions. But even when faced with a reality that is vastly different from anything we have experienced before, the hippocampus can rise to the occasion, bridging the past with the future.
      This takes time and effort -- but it helps to know that your brain has lots of experience doing just that.