How Screen Time Affects the Brain
- Dr. Joshua Beaudry
- Feb 3
- 4 min read
Most Americans are spending 7–9 hours per day on screens outside of work. That includes scrolling, gaming, streaming, and constant switching between apps.
And this matters—because screen time doesn’t just change attention… it changes the brain.
This impacts both kids and adults. In children, screen time can alter brain development. In adults, it can change mood, sleep, motivation, dopamine function, and long-term brain health.
The Brain Develops Bottom-Up… But Screens Train It Top-Down
The brain naturally develops in stages:
Brainstem → Cerebellum → Limbic System → Cortex
This is a bottom-up development pattern. The foundational systems develop first, then higher thinking layers come online.
But screens don’t train the brain from the bottom up.
They train it top-down:
Heavy frontal lobe stimulation
Constant cognitive interpretation
Dopamine-driven novelty
Minimal physical sensory feedback
And one of the biggest problems is this:
Screen time uses very little cerebellum.
The cerebellum is the region responsible for:
motor development
balance
coordination
eye tracking
emotional regulation
inhibiting or downregulating vestibular function
But screens largely remove the need for:
movement
real-time balance correction
physical interaction
body-based sensory integration
This can shift development away from cerebellar strength and into compensatory frontal lobe overuse.
What Screen Time Can Disrupt (Especially in Children)
When the cerebellum isn’t being trained properly, this can affect:
motor processing
eye movements and tracking
handwriting and fine motor control
emotional control
vestibular function (balance system)
This may show up as symptoms like:
dizziness or vertigo
tummy aches
motion sensitivity
poor coordination
emotional dysregulation
Screen Time and the Prefrontal Cortex
The prefrontal cortex governs:
focus
impulse control
emotional regulation
decision-making
In kids, excessive screen time can disrupt how this area develops and integrates with lower brain centers.
This can present as:
poor frustration tolerance
emotional outbursts
attention issues
impulsive behavior
difficulty finishing tasks
Dopamine: The Reward Center Gets Rewired
Screens create dopamine spikes through:
gaming rewards
fast scrolling
constant novelty
rapid scene changes
immediate stimulation with low effort
Over time, this rewires the reward system.
Here’s what happens:
small stimulation = big dopamine
normal life feels boring
motivation drops
task completion becomes harder
low effort becomes the standard
addictive pathways become overstimulated
Dopamine is what helps you:
finish tasks
take action
stay motivated through effort
But if dopamine is constantly triggered by screens, the brain begins to expect reward without effort, leading to motivation and drive problems.
Screen Time and Fight-or-Flight
Screen time can activate the autonomic nervous system and drive a person into sympathetic tone (fight-or-flight).
A simple way to tell if this is happening:
Check the hands
If screen time causes:
cold hands
clammy hands
sweaty hands
very dry hands
…the nervous system is shifting into stress physiology.
In younger children, we commonly see: cold + sweaty hands (which is a strong indicator the screen is pushing them into fight-or-flight)
Blue Light, Cortisol, and Blood Sugar
Screens also produce blue light, which signals the brain to stay alert.
This can:
increase sympathetic tone
spike cortisol
shift blood sugar regulation
So if someone experiences:
cravings
night snacking
energy crashes
feeling “wired but tired”
…it may not be a willpower problem—it may be a nervous system + blood sugar stress response.
Sleep Breakdown: Melatonin and Serotonin Drop
Chronic screen exposure decreases:
melatonin production
serotonin regulation
This disrupts:
sleep onset
staying asleep
deep recovery sleep
And this can be triggered by as little as 2+ hours of screen time, especially in the evening.
Long-Term Brain Effects
In both children and adults, chronic screen overload has been associated with:
neurodegeneration patterns
cortical thinning
gray matter loss
decreased melatonin production
developmental delays in children
The issue isn’t screens themselves—it’s how much, how often, and what type of screen usage is happening compared to movement-based, real-world sensory development.
How to Combat Screen Time Effects
You don’t have to be perfect—you just need to be strategic.
1. Blue Blocker Glasses
Helps reduce sympathetic activation and support circadian rhythm.
2. Reduce Scrolling
Limit fast-dopamine formats.
Instead:
read the printed word
watch slower-paced single shows
avoid flashing lights and rapid switching
3. Train the Cerebellum
Bring the brain back into bottom-up development.
Best cerebellar activities include:
running
jumping
balance activities
movement games
outdoor play
coordination-based exercises
Movement is brain development.
How We Can Help You Measure It
If you suspect screen time is impacting you or your child, we can objectively test what’s happening.
Neurodevelopmental Testing
Helps identify brain strengths and weaknesses such as:
cerebellar weakness
eye tracking issues
vestibular imbalance
coordination deficits
processing challenges
EEG Brain Mapping
Shows brainwave patterns and how the nervous system is functioning.
This tells us where the brain is stressed, overloaded, or compensating—so we can personalize the plan.
The Takeaway
Screen time isn’t neutral.
It shapes development, reward systems, stress physiology, motivation, and sleep. When the brain is trained top-down instead of bottom-up, the foundational systems—especially the cerebellum—can become underdeveloped and dysregulated.
The good news: the brain is plastic. With the right changes, the nervous system can stabilize and development can return to healthier patterns.
Life Springs Family Chiropractic – Denver, CO
Call/Text: (303) 770-0605
Website: lifespringsfamilychiropractic.com