spinally We love to think we can multitask.

Phones ping. Emails ding. TVs flash in the background. We tell ourselves we can work, talk, listen, and scroll at the same time.

But the science is blunt. You can’t.

What we call “multitasking” is really rapid task switching. Your brain doesn’t run tasks in parallel, like a computer with many cores. It moves from one to the next, back and forth, fast enough to fool you into thinking they run at once.

Researchers call it cognitive switching. Every time you swap tasks, the brain drops one context and loads another. Like shutting one file, opening the next.

That takes time.

The time is small — a tenth of a second, maybe two — but it adds up. Studies show constant switching can cut productivity by 40 percent. Forty. Because as you flip between tasks, you lose not just speed, but accuracy.

Psychologists call this the switch cost.

Say you read email, write a report, and listen to music with lyrics. Each time you glance at the inbox or catch a line in the song, your brain hits pause on the report. Then it needs a beat to remember where it left off. Like leaving your place in a book, then hunting for it again.

Neuroscience shows the brain pays for this in blood sugar, too. Switching tasks burns glucose. The more you switch, the faster you drain the tank. That’s why you feel fried after a day of “doing everything at once.”

It isn’t just work. Driving while talking on the phone? Same effect. You can do both, but reaction times stretch. Attention falls. Risk rises.

Stanford researchers found heavy multitaskers (people who swear they’re good at it) do worse at filtering out distractions. They struggle to hold information in working memory. Their focus leaks.

Because multitasking isn’t about talent. It’s about limits. The prefrontal cortex, the brain’s CEO, handles planning, decision-making, and attention. It can juggle one demanding task, maybe two simple ones. Add a third, it drops something.

The myth comes from speed. Switch fast enough, and it feels like you do two things at once. But the brain runs a single spotlight of attention. It just whips the beam around, leaving the dark in between.

Even tiny interruptions hurt. One study found that a 2.8-second distraction — a quick text check — doubled error rates. A 4.4-second break? Tripled them.

The more complex the task, the worse the hit. Reading while music plays is one thing. Writing while the phone buzzes, the Slack pings, the TV blares? Your brain shreds attention like paper.

So you can’t multitask. Not because you lack willpower, but because biology says no.

The brain runs a single line of thought. Break it, and you pay in time, energy, and mistakes.

Better to do one thing. Then the next. Then the next. Intention, Attention.

Now, where was I?