Is checking your email while you're waiting in line at the grocery store really hurting your ability to learn?

That's the basic premise of Matt Richtel's very popular New York Times story this week, "Digital Devices Deprive Brain of Valuable Downtime." The article couches its arguments in the language of science, but its actual scientific content is pretty sparse.

Only two studies are cited, and each gets just a few sentences and no caveats. No specific publications are given. One study suggested people learned better after a nature walk than a city hike, a proposition for which plenty of evidence exists. The other study, though, carried out in Loren Frank's University of California San Francisco lab was carried out in rats, a sometimes tenuous analog for humans, especially our brain activity. Richtel put it like this:


This is the only scientific evidence the Times gives that our brains' ability to learn is limited by frequent exposure to digital devices. That's a lot to pin on a few studies in rats.

To get a little more nuance and context, I called up Dr. Frank and asked him more about what his work said about our attachment to our digital devices.

"Reading my papers and reading the article, there is a big jump there," he said. But he felt comfortable putting the idea out there because there is "a lot of converging other stuff" outside of his own work that suggests filling our little downtime moments with Tweeting or email checking might not be the best idea.

"As far as we can tell, the brain takes advantage of -- speaking colloquially -- 'downtime,'" Frank said. "It's no longer focused on the outside world. It's recapitulating past experience internally."

What really matters, though, is not whether we're using a digital device but whether we're focused externally or internally.

"I think it probably is true that we have limited attentional resources and we can choose how much of the time we're focused on something internal versus external," Frank said. "If you do spend all of your time focused on external things, you're less able to allow internal processes to happen. And my guess is that those internal processes are pretty important. But that's not specific to digital devices, that's anything."

Perhaps, Frank did suggest, digital devices might make it easier to distract ourselves.

"There is the potential for low level cognitive engagement with things that could hinder other processes," he said. "That seems reasonably plausible to me, and I' d be surprised if that weren't right in some way."

But other stuff can inhibit those same processes. Reading the paper, paying very close attention to other people talking on the train, listening to talk radio. All of these things could conceivably distract you from letting your mind rest. "My guess -- and this is just a guess -- is that it has much more to do with attentional state than what specifically people are focused on," Frank said.

The Times series may be called "Your Brain on Computers," but one device that predates the digital age may be the one that's particularly bad for your neurons.

"Television causes people's brains to enter a weird state where they are passive but focused," Frank said. "With Television, as far as I understand it, not a lot of higher thinking goes on."

And that's one thing missing from the Times article: a sense of the full breadth of choices humans can make, nearly all of which are technologically mediated.

In their version of the story, it's the lady who watches television and checks her email while on the treadmill versus the trail runner. But what about the person who runs in city streets listening to podcasts (like myself)? What about people who play basketball for exercise? Would they be better off running because the game distracts them from internal processes?

Another thing that's missing from the story: numbers. We don't really know what the scale of the problem we're dealing with is. Are devices impairing our learning a little or a lot? No one really knows, but the Times leaves the impression it's the latter without providing the evidence that that's the case.

If you want to learn more about Frank's work, head to his publications website, which has copies of about a dozen papers and book chapters.