As we consider our resolutions and goals for 2018, many of us will vow to cut down on screen time. We will have different reasons for doing so, citing a waning inability to focus or a desire to free ourselves from information overload. But how necessary is this? In other words, does screen time have a measurable impact on the brain? And if it does, how much do we need to cut down in order to maintain a healthy relationship with our devices? Researchers have some important new findings to share with us on the matter.

But first—what do we mean by “screen time,” exactly?

“The cognitive resources required to watch television versus play a first-person shooter game on a PlayStation 3 are quite different,” writes Kayt Sukel for the Dana Institute. “Every day, virtual technologies are becoming more vivid, involving more senses and offering more interactivity for users. That makes the concept of ‘screen time’ difficult to properly define, and makes it difficult for researchers to design studies that keep up with the latest technology.”

Plus, studies suggest that many of us can benefit from screen activities like video games, which have been shown to increase brain volume.

The kind of screen time we’re addressing in this article is the kind most of us engage in during our day-to-day lives: namely, reading. We read the news, our social media feeds, our friends’ texts. It could even be argued that we “read” images. So how do these activities affect the brain, and how can we change our behaviour to achieve a healthy balance of on-and-off-screen engagement?

Let’s start by taking a look at some of the latest research.

How Does Screen Time Impact the Brain?

In a brand new study published in Acta Padiatrica, researchers found that brain connectivity in children is increased by the time they spend reading books and decreased by the length of exposure to screen-based media.

Researchers advertised the study to parents of private school children in Cincinnati, USA, having volunteers complete surveys on “how many hours their children spent on independent reading and screen-based media time, including smartphones, tablets, desktop or laptop computers, and television.”

Magnetic resonance imaging was then used to analyse the resting-state connectivity of nineteen children as they read books or used their devices. Researchers were looking to see how well-connected the left visual word form area was with other brain regions. What they found is that screen time negatively impacted connectivity.

“Time spent reading was positively correlated with higher functional connectivity between the seed area and left-sided language, visual and cognitive control regions,” the authors write. “In contrast, screen time was related to lower connectivity between the seed area and regions related to language and cognitive control.”

Not only do these results suggest we need to limit our screen time; they also “underscore the importance of children reading to support healthy brain development and literacy.” Books are here to stay.

Screen time also affects our emotions, making us unhappier the more we tap, scroll, and swipe.

Monitoring the Future, a survey funded by the National Institute on Drug Abuse and designed to be nationally representative, has been tracking high schoolers each year since 1975, recording happiness levels and the amount of leisure time spent on nonscreen activities like in-person social interaction and exercise versus, more recently, screen activities like texting, social media, browsing the web.

“The results could not be clearer,” writes Jean M. Twenge, professor of psychology at San Diego State University. “Teens who spend more time than average on screen activities are more likely to be unhappy, and those who spend more time than average on nonscreen activities are more likely to be happy. There’s not a single exception. All screen activities are linked to less happiness, and all nonscreen activities are linked to more happiness.”

Social media use, in particular, correlates with the most unhappiness. Twenge describes one study where college students with a Facebook page took short surveys on their phones over the course of two weeks. Five times a day they would receive a text with a link asking them to report on their mood and how much they’d used Facebook so far that day. “The more they’d used Facebook,” she reports, “the unhappier they felt.”

Heavy screen time also reduces our chances of getting enough sleep, which is essential for good brain function.

“I asked my undergraduate students at San Diego State University what they do with their phone while they sleep,” says Twenge. “Their answers were a profile in obsession. Nearly all slept with their phone, putting it under their pillow, on the mattress, or at the very least within arm’s reach of the bed. They checked social media right before they went to sleep, and reached for their phone as soon as they woke up in the morning (they had to—all of them used it as their alarm clock).”

It’s no coincidence, she says, that fifty-seven percent more teens were sleep deprived in 2015 than in 1991, and that twenty-two percent more teens failed to get seven hours of sleep in 2015 than in 2012. That’s around the time when most teens got a smartphone.

It remains to be seen how increased screen time affects social skills, but anyone can see it takes up time that might otherwise be spent engaging in real human contact.

“In the next decade,” Twinge warns, “we may see more adults who know just the right emoji for a situation, but not the right facial expression.”

Strategies to Limit Screen Time

The following are a few recommendations we’ve cooked up to help you (and your kids) cut down on screen time in the new year. Feel free to suggest your own in the comments section below.

1. Use a time management app.

This one might seem paradoxical since it gives you one more reason to look at your device, but if it reduces overall screen time, then it’s well worth it. Try Onward, an app that breaks down your daily device use by category, to get an idea of how you currently spend your time and set new goals.

2. Make access harder.

Turn your phone off or keep it in a part of the house you have to walk over to. Take social media apps off your phone so that you can only check your Facebook or Instagram when you use your laptop. Set your accounts to “Don’t save password” so that you have to enter your log-in details each time you want to check your feed.

3. Set parameters for daily use.

If you spend all day in front of a screen for work, make sure you balance that screen time with nonscreen time after you punch out. If you spend all day doing nonscreen activities, set rules for yourself so that you don’t binge once you get off work. Whatever parameters you set, keep them consistent; the brain likes predictability.

4. Replace screen activities with nonscreen activities.

Don’t just give up one activity without a plan for replacing it with something else. Have an idea of which nonscreen activities you enjoy and would like to incorporate into your schedule when you’ve suddenly got oh-so-much more time because you’re on Facebook for twenty minutes instead of an hour.

5. Involve your friends, family, and colleagues.

We’re products of our immediate environment. If the people around us are limiting their screen time as well, it will be easier for us all to achieve our goals. Remember: Over 2 billion people are facing the same challenge; let’s make these changes together.