2-year-olds adept at using touch-screen technology

This level of interactivity is akin to play, say the researchers, who suggest that the technology might have a potential role in childhood developmental assessment.

They base their findings on 82 questionnaires on touch screen access and use, completed by the parents of children aged between 12 months and 3 years.

Parents were asked how long their child used touch screens each day, and whether s/he was able to unlock the screen, swipe through pages or images, and recognise and interact with specific features such as app icons for games.

The parents were also asked if they had downloaded any games or apps specifically for their child's use. The age of their toddlers ranged from 20 to 30 months, and just over half (57%) were boys.

Most of the parents (82%, 67) said they owned a touch screen device such as a smartphone or tablet.

Of these, most (87%, 58) gave their child the device to play with for an average of 15 minutes a day, and nearly two thirds (62%) said they had downloaded apps for their child to use.

Nine out of 10 (91%) parents who owned a touch screen device said their child was able to swipe; half (50%) said their child was able to unlock the screen, and nearly two thirds (64%) felt their child actively searched for touch screen features.

The average age of the toddlers with the ability to perform these three skills was 24 months, while the average age for identifying and using specific touch screen features was 25 months--almost three out of four (72%) parents felt their child was able to do this.

Overall, one in three of the toddlers could perform all four skills by the average of 29 months, and children as young as 12 months regularly used touch screens.

In 1999 the American Academy of Pediatrics recommended that screen time be discouraged in children under the age of 2, on the grounds that it risked exposure to unsuitable material and the displacement of other developmentally important interactions and play.

These recommendations were made before the advent of touch screen media, which might have a different impact on the developing brains of toddlers, suggest the researchers.

"Interactive touch screen applications offer a level of engagement not previously experienced with other forms of media and are more akin to traditional play," they write. "This opens up the potential application of these devices for both assessment of development and early intervention in high risk children."

Nevertheless, they caution: "Many applications designed for infants and toddlers already exist, but there is no regulation of their quality, educational value, or safety. Some of the issues that arise with passive watching of television still apply."