Under the new guidance, students in early education and kindergarten through first grade will have no weekly classroom screen time. Students in grades 2 and 3 will be limited to 1 hour and 40 minutes per week, with those in grades 4 and 5 limited to 2 1/2 hours, students in grades 6 through 8 limited to 6 hours per week, and high school students limited to 10 hours per week.

The limits include time spent on screen-based homework.

“Screen time is literally changing the trajectory of brain development. It’s growing the visual cortex at the expense of the areas responsible for language, reading and social skills,” said Jane Tavyev Asher, MD, pediatric neurologist and director of the Division of Pediatric Neurology at Cedars-Sinai Guerin Children’s. “Parents should actually be very delighted that their kids are going to have less screen time in the school setting, and they should view the school as working as their partner in helping with their child’s brain development.”

As the new policy takes effect this school year, the Cedars-Sinai Newsroom spoke with Tavyev Asher about why reducing screen time can benefit children’s brain development—and how parents can reinforce healthy screen habits at home.

Why were these new screen time policies needed?

Research continues to show that excessive screen time can affect how children’s brains grow and develop. During childhood, the brain is building important skills for language, reading, attention and social interaction. We want the brain to develop for reading, language and social skills. And screen time is really growing the visual cortex at the expense of all of the other parts of the brain.

Sharply reducing screen time at school can help create more opportunities for students to have active learning, conversation and deeper cognitive development in the long run.

Now that schools are seeing the neuroscience behind what screen time does to the developing brain, many are beginning to embrace this research and implement limits. They want what’s best for students’ brain development, just as parents do. At the end of the day, we’re all working toward the same goal: helping our children learn, grow and thrive.

Why is limiting screen time especially important during early childhood?

Early childhood is a critical period for learning to speak, read, write and develop social skills. During these years, the brain’s auditory and language centers are rapidly developing through conversation and human interaction.

For example, speech development begins around age 1, when children start learning how to speak. This process depends on the development of nerve signals and the continued growth of the auditory cortex, which develops significantly during the first few years of life. The auditory cortex is also the part that builds not just language but also social interaction.

Excessive screen use may interfere with these processes by overstimulating visual pathways while reducing opportunities for face-to-face communication, language development and recognizing social cues such as facial expressions and body language.

How can screen use affect brain development in middle schoolers?

Higher-level cognitive functions really begin to take off around age 12. This is when intellectual curiosity starts to develop. It’s a stage where children naturally begin making connections between ideas, such as reading one thing, connecting it to something else they’ve learned, asking questions, and wanting to find the answers. That’s exactly how we want their brains to develop.

But if everything is fed to them passively through AI or excessive screen-based learning, that part of the brain isn’t being exercised in the same way. They’re consuming information rather than actively thinking, questioning and making connections. It’s wonderful that our schools are finally coming to this realization and changing the way the curriculum is given to our children.

What screen time advice do you have for parents of high schoolers?

For a high schooler, I would try to keep the same guidelines in the home that you’ve done for the younger children. The reason for that is they still have that developing brain, and screen time is still very addictive.

I think at this age, they really do have the understanding as to why screens are not ideal for them. By the time they’re in high school, teenagers can understand the logic behind reducing screen time. This is the time when their intellect is developing. They can read the studies about it. As parents, this is also an ideal time to expose them to the studies that are showing what screen time addiction is doing to the brain in the long run.

How should parents approach smartphones for middle and high school students?

The smartphone is really the worst form of screen time because it is so easily accessible in the pocket. It’s easier to become addicted to that. So, it’s important to monitor how children access and use their smartphones.

There is so much social growth that happens in middle school. If you can just get the kids over that hump without a phone, then you can keep them from getting addicted to that phone.

There’s a program called “Wait Until 8th.” It’s a movement where parents sign a pledge to delay giving their child a smartphone until at least the end of eighth grade or until they’re 13 years old. When families make this commitment together, it creates a community where fewer kids have smartphones early on, which helps reduce the peer pressure to get one before they’re ready. It gives parents support in setting healthy boundaries and makes it easier for children to wait alongside their friends.

If you need to be in touch with your teenager, give them a simple flip phone that has no internet access. This way, they can call who they need to call. In some phones, you can also program who they call or receive calls from.

How can parents set and enforce screen time limits at home?

Parents have a huge influence on how children develop their relationship with screens. It’s much easier to not introduce screens than to set limits or take it away later in life. Instead of focusing only on taking screens away, parents can help children discover other activities, like reading, creative play, spending time outdoors and connecting as a family.

It’s important to point out that parents should model habits they hope to see by practicing healthy screen use themselves, since children are more likely to follow behaviors they observe at home.

Firstly, implement a no-screen-time rule at least two hours before bedtime. This will help kids avoid bright lights right before bed, promoting deeper sleep. Secondly, avoid screens during mealtime. Mealtime is a great time for the family to sit together and have conversations. There are so many positive studies about what family mealtime does for children’s social development and for their cognitive development.

Read more from Cedars-Sinai Stories and Insights: A Family Guide to Teens, Screens and Social Media

Wei Gao, PhD, director of Neuroimaging Research and professor of Biomedical Sciences and Imaging; Jane Tavyev Asher, MD, director of the Division of Pediatric Neurology at Cedars-Sinai Guerin Children’s; and David H. Rowitch, MD, PhD, deputy director of Research at Cedars-Sinai Guerin Children’s, sat down with the Cedars-Sinai Newsroom to talk about their work.

Mapping Infant Brain Development

Gao said that besides primary motor connections, social-emotional connections are among the first an infant’s brain makes, and that these connections ladder up to other levels of intelligence.

“The first year is where you need to pay very special attention to the social-emotional development of the baby,” Gao said. “You want to provide sensitive support to the baby so the baby can develop a secure attachment with you as a caregiver. That has long-term impacts to their later achievements and quality of life.”

Social-emotional development is the key piece that integrates the core hierarchy of brain development, Gao said. It starts with sensory and motor regions to ensure early survival, then progresses to higher-order cognitive areas to develop more sophisticated social and emotional regulation skills, which are critical for mental wellbeing, learning and adaptation.

Gao and his team previously created one of the first detailed maps of connections established between different regions of the brain during the first two years of life. They aim to better understand typical brain growth trajectories, as well as how risk factors—including maternal health, prenatal exposures to harmful substances, and family environment—can influence brain growth and a child’s development.

The investigators are now conducting the Healthy Brain and Child Development study, which will follow more than 7,000 children from birth to 10 years old. Regular conversations with caregivers and imaging of the children’s brains will help investigators correlate development of brain connections with other factors in a child’s life.

“We want to use advanced imaging as a tool to detect deviations as early as possible so that we can hopefully bring them back to the normal trajectory,” Gao said.

The Effects of Screen Time During Babyhood

Tavyev Asher is a pediatric neurologist who collaborates with Gao. She said a baby’s brain develops sensory abilities first, followed by language and social skills—a process that can be derailed by screen time.

Before the age of 12, the auditory and the visual areas of the brain are being fine-tuned, but looking at a screen develops only the visual cortex of the brain, Tavyev Asher said. The auditory cortex, which supports social interactions, develops through in-person interaction.

“Real life moves at a much slower pace than the rapidly flipping images on a device or screen,” Tavyev Asher said. “The brain is developing its communication patterns in those first few years of life, so you are training that brain exactly what it needs for its future. If you're exposing that brain to a screen, that brain thinks it needs to be able to pay attention to these rapidly changing images but not to the slower things of the real world.”

To make sure language, hearing and social skills develop, Tavyev Asher urged parents and caregivers to prioritize face-to-face interaction with their babies. She also said that early screen time can affect a child’s later learning skills, including reading and writing proficiency.

“Reading comprehension, reading speed, reading fluency and memorization are all going to be enhanced if you're reading from an actual book rather than on the screen,” Tavyev Asher said. “The single most important thing that parents can do for their children right now is to keep them off screens between the ages of 0 and 3.”

The Importance of Genetics

Rowitch, a neonatologist, developmental neuroscientist and expert on pediatric neurological disease, said that genetic tests developed over the past 10 years can analyze all 3 billion base pairs, the letters that make up a person’s genetic code. These tests can offer crucial information on an infant’s brain development as well as the child’s future mental and physical health.

“We find that almost 80% of babies with a genetic condition exhibit a neurological manifestation,” Rowitch said. “For example, that could be weakness of the muscles, seizures or a structural abnormality of the brain that we identify by MRI. It is important to understand and capture these conditions to ensure the correct diagnosis and treatment.”

Pairing genetic testing with a map of normal brain development such as the one created by Gao can help clarify how genetic conditions change development patterns, Rowitch said. This could be especially true for babies born preterm.

“We want to be able to anticipate future health or neurodevelopmental problems,” Rowitch said. “The earlier we detect alterations, the sooner we can intervene to improve the child's developmental trajectory.”

Detecting serious genetic conditions at birth also could have implications for a child’s school readiness and long-term health outcomes.

“Together, these studies emphasize the importance of early brain development. If we understand how genetics affects school readiness, that starts to open up another set of questions,” Rowitch said. “How can we make a child school-ready who might otherwise be in a high-risk category? If we can bring together genetics, brain mapping and cognitive assessment, we can create interventions that can help every child reach their potential.”

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