How Does Screen Time Really Affect Toddlers? Not for the Better, Scientists Say

The most impacted part of the brain is that which affects literacy and cognitive skills.

A new study explored the effect screen time has on toddlers’ brain development—and the findings were pretty grim.
Conducted by the Cincinnati Children's Hospital, the study worked with children 3 to 5 years old and was published Monday in the journal JAMA Pediatrics. It found that those who used their screens more than the recommended hour per day, and without their parents involvement, had lower brain development levels. Specifically affected were their brains’ white matter tracts, which affect literacy and cognitive skills.  
"This is important because the brain is developing the most rapidly in the first five years," Cincinnati Children's Hospital pediatrician and clinical researcher Dr. John Hutton said. "That's when brains are very plastic and soaking up everything, forming these strong connections that last for life."
The study used 47 brain-healthy children and determined how much screen time they were getting as well as what kind of screen time. It used used MRI scans and cognitive skills tests to determine its findings.
Researchers did stress, though, that screen time does not necessarily cause brain damage.
"Perhaps screen time got in the way of other experiences that could have helped the children reinforce these brain networks more strongly," Hutton told CNN.
To help manage the amount of screen time young children engage in, pediatricians recommend using calculation tools to establish a family media plan

The American Academy of Pediatrics says that babies under 18 months old should be exposed to the environment as opposed to screens, and that children aged 3 to 5 can benefit from occasional educational TV, but they learn much better when educational things are co-viewed or when kids work with a caregiver