We’re fragmenting our brains …

Back when personal computers were slower, clunkier machines with mechanical hard drives, there was a maintenance chore many Windows users knew by one peculiar name: “defrag.” Over time, pieces of files could become scattered across different physical locations on the hard drive. The computer could still find them, but retrieving those separated pieces could take longer because the drive’s mechanical read/write head had to move from one location to another. The files had become “fragmented.”

Windows included a tool for dealing with the problem: Disk Defragmenter. Command the computer to defrag, and it would begin reorganizing the scattered pieces of files so they could be stored more efficiently. Some versions even let you watch the process on the screen as blocks were analyzed and rearranged. It could take a while, but there was something strangely satisfying about watching disorder gradually become order.

Human beings are obviously not computers, and brains do not store thoughts as files scattered across a hard drive. But that old computer problem provides a surprisingly useful picture of something we are doing to ourselves.

We’re fragmenting our brains. And we seriously need to learn how to defragment them.

“Fragmenting our brains” is a metaphor. Our brains are not physically breaking apart, and thoughts are not files scattered across brain tissue. The fragmentation is happening in the way we use our brains. Activities that need continuous attention are increasingly being broken into smaller pieces as we repeatedly shift our attention away and then try to return.

It happens so routinely that we can miss what we are doing.

For example, a woman sits down at her desk to finish a proposal. She has been working for several minutes when her phone vibrates. A friend has sent a text. Nothing is urgent, but she reads it and answers. Her friend responds, so she answers again. Then she puts down the phone and turns back to the proposal.

The document is exactly where she left it. Her brain is not. Before the text arrived, she was following what she had already written and deciding what needed to come next. The text required her to attend to a different conversation. When she returns to the proposal, she rereads part of the page in order to recover what she was doing.

Later, an email notification appears. She opens it, reads the message and replies. Again, she returns to the proposal and has to recover the thread of her work.

Then she reaches a difficult section. She tries a sentence, deletes it and thinks about how to explain the idea. Her phone is lying beside the keyboard. This time it does not vibrate. No message appears. Nobody interrupts her.

She picks it up anyway.

Now she has interrupted herself.

By lunchtime, she may truthfully say she spent the morning “working on the proposal,” but her brain did not spend the morning continuously engaged with it. The work was repeatedly broken apart by unrelated information that had to be processed before she could return.

This is one way we are fragmenting our brains.

Sometimes other people interrupt us. Sometimes our devices do. Increasingly, we interrupt ourselves. A difficult moment, a little boredom, or the simple impulse to see whether anything new has happened can be enough to make us leave what we were doing.

And leaving has a cognitive cost.

Researcher Sophie Leroy found that when people moved away from unfinished work, some of their attention could remain with what they had just left and interfere with what they did next. She called this attention residue. Other researchers have found that even receiving a phone notification can impair performance on an attention-demanding task when the person never answers the phone.

The interruption, in other words, does not have to last long to break continuity.

Short-form video fragments attention in a different way.

Later that evening, the same woman opens Instagram Reels. She is not being interrupted, watching videos is what she has chosen to do.

The first video shows a comedian telling a story. She watches for twenty seconds and swipes. The next shows someone preparing food. Before it ends, she swipes again and lands on an argument between two strangers. Another swipe brings up a dog. Another brings up a political clip. Another brings up someone demonstrating an exercise.

Half an hour passes.

She has been engaged the entire time, but engagement is not the same as sustained attention. Her brain has not spent thirty minutes following one developing subject. It has repeatedly begun processing one thing, abandoned it, and oriented to something new.

This is another way we are fragmenting our brains.

The distinction is important. In the first example, something kept breaking into an activity that required continuity. In the second, rapid change was the activity. The short-form feed provided an environment in which leaving one thing for another could happen over and over with almost no effort.

Researchers have begun testing that pattern directly.

In a 2025 experiment, participants were assigned to short-form-video conditions that allowed different amounts of switching. Those allowed unrestricted switching showed a significant decline in prospective memory —– the ability to remember to carry out an intended action later. An earlier experiment had also found poorer prospective-memory performance after TikTok use than after conventional YouTube, X (Twitter), or no activity.

Those experiments are relatively small and should not be made to carry more weight than they can. But their findings fit a much larger body of research. A 2025 meta-analysis in Psychological Bulletin combined 71 studies involving 98,299 participants and found that greater short-form-video use was associated with poorer cognitive functioning, with the strongest associations involving attention and inhibitory control.

Inhibitory control is part of what allows us to resist an impulse when acting on it would interfere with what we are trying to do. It is what the woman at her desk needed when she reached a difficult section of the proposal and wanted to pick up her phone. On an endless short-video feed, there is little need to resist the desire for something different. If one video becomes boring, a swipe immediately supplies another.

The meta-analysis does not prove that short-form video causes poorer attention or inhibitory control. Much of the evidence is correlational. People who already have difficulty regulating attention may use short-form video more heavily; heavy use may contribute to those difficulties; both may occur. The evidence warrants concern without warranting sensational claims that short videos are “destroying” our brains.

But there is another clue that fragmentation is affecting us, and we do not need a laboratory to recognize it.

We can see it when life asks us to stay.

When staying becomes difficult
A man chooses a movie he genuinely wants to watch. Twenty minutes later, his phone is in his hand.

The movie has not stopped. He has not decided that he dislikes it. He continues watching while also checking messages or scrolling through something else. One screen is no longer enough to occupy his attention.

Researchers call this second-screen use, and experiments have shown that dividing attention between television and another screen can increase cognitive load and reduce comprehension and recall of what was watched.

The important point is larger than whether someone remembers every detail of a movie. Even an activity chosen for pleasure can now be fragmented by another stream of information.

Reading makes the same pattern impossible to miss.

Someone opens a book he genuinely wants to read. A few pages later, he checks his phone. He returns to the book, reads several more pages and checks again. Eventually he may conclude that he simply cannot get into books anymore.

Research on reading has documented attentional disruptions occurring, on average, about every four minutes, with heavier media multitaskers experiencing more media-related interruptions. Experimental research also shows that multitasking while reading can lengthen reading time and, under some conditions, impair comprehension.

A book exposes fragmentation because reading depends on continuity. What is being said now often depends on what was said several pages earlier. The reader has to “remain” with the material long enough for meaning to accumulate.

Conversation can expose the same problem.

Someone we care about is sitting across from us telling us about something that happened. The phone lights up, and our eyes move toward it. Or the phone never lights up at all. The conversation reaches a quiet moment, and we reach for it ourselves.

Research on phone use during face-to-face interaction has found effects on perceived attentiveness and conversation and relationship quality. Not every study has produced identical findings, and merely having a phone nearby does not automatically ruin a conversation. But the behavior itself is revealing.

A real person cannot be swiped.

He may pause while searching for the right words. She may need several minutes to explain what happened. The important part may come near the end rather than in the first fifteen seconds. Being present with another person requires allowing that person’s thoughts to unfold at a pace we do not control.

Fragmentation becomes especially visible when we no longer want to wait.

And boredom may be helping drive the cycle.

When digital content becomes boring, switching seems like the obvious solution. Find another video. Skip ahead. Look for something better. Researchers tested that assumption across seven experiments involving more than 1,200 people.

People expected switching to make them less bored.

It did the opposite.

When participants were free to switch between videos or jump around within them, they became more bored, while their attention, satisfaction, and sense of meaning declined. When they stayed with the viewing experience instead of continually changing it, they became more immersed and enjoyed it more.

That finding helps explain something otherwise puzzling about fragmentation. We leave because staying no longer feels stimulating enough, but repeatedly leaving can prevent the very immersion that makes an experience satisfying.

The result can become a cycle. We feel bored, so we switch. Switching prevents immersion. Without immersion, the experience becomes less satisfying. Then we want to switch again.

A movie feels too slow. A book feels demanding. A conversation drags. Work becomes intolerable as soon as it becomes difficult. The next source of stimulation is always available, so we leave before the experience in front of us has had time to become absorbing.

This is the real impact of fragmentation.

It is becoming harder to stay.

And some of the most valuable things our brains do require us to stay.

Understanding something difficult takes time because new information has to connect with what came before. Memory depends partly on whether we attended well enough to information for it to be encoded in the first place. Stanford researchers have found that attention lapses predict later memory failures and that heavier media multitasking is associated with more attention lapses and poorer memory performance.

Learning requires continuity. So does serious thought. So does becoming absorbed in a story. So does listening closely enough to understand another human being.

Fragmentation does not merely steal a few minutes from the workday, it can interfere with the conditions under which understanding, memory, immersion, and connection occur.

That is why we seriously need to defragment our brains.

Defragmenting the brain
There is no neurological version of the old Windows utility. We cannot click a button and watch the brain reorganize itself. In the terms of this metaphor, defragmenting means restoring continuity where repeated switching has become habitual.

That does not require abandoning technology, but it does require addressing the behavior that creates the fragmentation.

If concentrated work is repeatedly being interrupted by notifications, remove the unnecessary notifications. If the phone is being picked up automatically whenever work becomes difficult, put it somewhere that makes checking a deliberate decision rather than a reflex. If a movie is routinely accompanied by a second screen, watch one screen. If short-form video has become an hour of almost continuous switching, reduce the endless-feed experience rather than pretending each thirty-second video exists in isolation.

Then practice staying.

Read long enough for the impulse to check the phone to appear — and let the impulse pass. Give a conversation your attention without keeping another source of stimulation within reach. Work through the difficult part of a task instead of immediately escaping it. Watch the movie you chose to watch without simultaneously asking another screen to entertain you.

These are ordinary acts, but they restore something fragmentation removes: continuity.

The brain’s capacity to change with experience is called neuroplasticity. That does not mean every swipe rewires the brain or that a few uninterrupted afternoons will magically repair attention. It means experience and practice can change neural functioning. The patterns we repeatedly practice are therefore worth taking seriously.

Defragmenting is not a one-time cleanup. If the same conditions keep breaking attention apart, fragmentation simply begins again.

Preventing that means deciding what deserves permission to interrupt us. Some interruptions are necessary, but many are not. It means noticing the difference between choosing to stop an activity and automatically leaving because something newer appeared. It means refusing to let every moment of boredom become a command to switch.

And it means protecting parts of life from simultaneous streams of stimulation.

The phone does not need to accompany the movie. A conversation does not need a second conversation happening on a screen. Difficult work does not need to share every few minutes with whatever has appeared online. A book does not need to compete with a feed designed to produce something new with every movement of a thumb.

Years ago, we ran Disk Defragmenter because scattered pieces made the computer work harder to do what it was supposed to do. Human brains do not fragment that way, and the metaphor should never be mistaken for literal neuroscience.

But we are scattering something valuable.

Our attention is being broken across more interruptions, more switches, and more competing streams of information. We are participating in that fragmentation every time we reflexively leave one experience for another.

The way back begins with a surprisingly difficult act: Stay.

Scotty