A cognitive neuroscientist says small moments of waiting can help the brain rest — and many of us keep filling them with our phones

Scrolling through Substack last night, I came across a note by cognitive neuroscientist Dr. Julie Fratantoni that stopped me mid-scroll, which felt appropriate given what it was saying.

Her point was simple: the small margins of waiting — the line, the elevator, the gap between meetings — are some of the only moments most modern brains ever get to genuinely rest. And we’ve been filling them. Every pause now has a reflex. Phone out, scroll, something in the ears. We’ve built a life with almost no cognitive gaps in it, and we don’t notice because each fill feels so small.

I put my phone down and just sat with that for a minute.

Then I picked it up again, screenshot the note, and made notes for this article. Which says everything.

What those small margins actually are

Standing in line at a coffee shop last week, I noticed my hand move toward my phone before the thought had even fully formed. I wasn’t bored yet. I wasn’t uncomfortable. The line was maybe four people deep. And still, my body reached.

I caught myself and put the phone back. And then I just stood there, feeling faintly ridiculous, staring at the specials board without reading it, letting my mind do whatever it does when you stop managing it.

Now I realize that the margins Dr. Fratantoni is talking about are not long.

A four-person queue. The two minutes before a meeting starts. The elevator ride.

Not sleep, not meditation, not a dedicated stillness practice. Just unstructured, undirected mental time that used to exist naturally inside a day and now almost never does. But the accumulation matters.

And we’ve been filling them.

Every pause now has a reflex. Phone out, scroll, something in the ears, something on the screen. We’ve built a life with almost no cognitive gaps in it, and we don’t seem to notice because each fill feels so small. It’s just a quick look. Just a few seconds. Just something to do with your hands.

But the accumulation matters. The brain isn’t idle during those gaps. It’s doing something specific.

What the brain does when you let it wander

Neuroscientists call it the default mode network — the system that activates when you’re not focused on a task. For a long time it was treated as the brain at rest, almost background noise. But the research has shifted significantly. The default mode network is now understood to be involved in memory consolidation, self-reflection, creative thinking, and the kind of mental housekeeping that makes it possible to process what has happened to you.

When you stare out a window and your mind drifts, you’re not wasting time. You’re integrating it.

The problem is that this system only activates when you’re genuinely doing nothing. Scrolling doesn’t qualify. Scrolling is still cognitive input, still sensory demand, still a mild but continuous drain on attention. What looks like rest is often just a different kind of stimulation.

Dr. Fratantoni puts it plainly: we’ve lost the ability to be bored, and with it, the space the brain needs to stay healthy.

Why stillness feels so uncomfortable now

I want to sit with that discomfort for a moment, because I think it tells us something important.

Most people, when they try to do nothing, don’t feel peaceful. They feel restless almost immediately. There’s a low-level anxiety that rises when there’s no external content to direct attention toward. Research on what psychologists call “aversion to idleness” suggests we’d rather do something, almost anything, than simply be with our own minds.

A widely discussed study found that a significant number of participants preferred giving themselves mild electric shocks to sitting alone with their thoughts for fifteen minutes. The conclusion was framed as a quirky finding, but I think it points at something real: unoccupied mental time forces an encounter with whatever is actually there. The thoughts you’ve been outrunning. The feelings you haven’t processed. The vague dissatisfaction or longing that doesn’t have a name yet.

We scroll, in part, because we don’t want to meet ourselves in the silence.

The version of rest we’ve replaced with stimulation

There’s a particular kind of tiredness that comes not from doing too much, but from never actually stopping. It’s the tiredness of being constantly held at a low level of alertness, never fully engaged but never fully released. You end the day depleted but not in a way that sleep fully repairs, because sleep alone doesn’t process what the default mode network was supposed to handle while you were awake.

I’ve noticed it in myself. A flatness that appears after long stretches where every gap has been filled. Not sadness. Not stress. Just a kind of muted quality to things, a sense that I’ve been moving through the day without quite landing in it.

When I trace it back, it’s usually preceded by days where I didn’t let my mind wander. Where I commuted with a podcast, waited in lines on my phone, filled every pause with noise. Days where I was never technically bored but also never truly rested.

What happens when you just stand there

The coffee shop line experiment was minor, but it was something. Without the phone, I noticed the light coming through the window, the particular smell of the place, the way the barista was efficient but unhurried. I noticed I was a little tired. I noticed a flicker of something like ease.

None of that would have been available to me if I’d been scrolling.

Dr. Fratantoni suggests starting small. Next time you’re waiting: do nothing. Let people think you’re strange. Let the mind go where it wants. She frames it as cognitive hygiene, a micro-habit with outsized returns for brain health and longevity.

I’d add that the returns aren’t only neurological. Something about standing in your own quiet, even briefly, reminds you that you exist in a way that passive consumption doesn’t. That you have an inner life worth sitting with, even when it’s unresolved, even when it drifts.

What we’re really protecting against

The question underneath all of this isn’t really about phone habits. It’s about what we’re afraid will happen if we stop.

Most of us fill the gaps not because we love content but because the alternative feels like falling into something we’re not ready for. Boredom, yes, but also awareness. A kind of presence that asks more of you than distraction does.

The irony is that the things we’re avoiding — the unprocessed feelings, the unfinished thoughts, the question of how you’re actually doing — don’t disappear when we scroll past them. They accumulate. They resurface later, heavier for having been postponed.

The margin you give your brain in a four-person queue is not a small thing. It might be one of the few moments in the day where something in you is allowed to breathe.

A quiet invitation

Not to overhaul anything. Not to start meditating, or commit to a phone-free hour, or turn idleness into another self-improvement project.

Just this: next time you’re standing somewhere waiting, try leaving the phone in your pocket. Let it be uncomfortable. Let your mind wander to whatever it reaches for.

Notice what comes up when you stop managing what doesn’t.

That wandering is not wasted time. It might be the most useful thing your brain does all day, and you’ve been interrupting it before it could start.