Spending too many hours looking at screens could change the shape of toddlers' brains, a study has warned. Scientists took brain scans of children aged between three and five and compared the results with screen use.
Those who spent the most time on tablets, phones, and the TV had less white matter in their brain, results showed. White matter is a sheath over the brain which helps send messages from one area to another through 'tracts'.
The tracts affected included those which support language skills, such as speech, thinking, and reading. The same children also scored lower on literacy tests, according to the results of the Cincinnati Children's Hospital Medical Center study.
But critics of the research implied the findings were misleading and urged parents not to worry about whether their child's brain is 'damaged'. The study, published in the Journal of the American Medical Association's Pediatrics, involved 47 healthy children - 27 girls and 20 boys.
Lead author Dr. John Hutton and colleagues asked their parents to report how much the children used screens.
This was using the screen test, a 15-item questionnaire that took into account easy access, frequency of use and content viewed. A low score reflects good adherence to screening recommendations by the American Association of Pediatrics (AAP).
The AAP advises children aged between three and five to spend no more than one hour a day looking at screens. At the same time, the children also had MRI scans taken and took part in three standard tests that measured language, including their vocabulary, reading, and speed of information retrieval skills.
Youngsters with a high ScreenQ score had lower brain white matter quality, which affects the formation of myelin.
Myelin is a fatty substance that covers the nerve fibers of white matter in the brain. It allows nerve impulses to quickly move in 'tracts', which send messages between the different parts of the brain.