SINGAPORE - Given how pervasive mobile devices are in homes these days, it is not surprising that more parents are using e-books to engage their young children.

There is a lot to be said in favour of e-books. They are portable and the text is supplemented with colourful animation and audio that seem to capture the attention of young children.

But several studies into reading show that printed books are far better at developing language skills among children, apart from honing their reasoning and thinking abilities. These benefits flow naturally when a child gets immersed in reading at a young age.

One of the most interesting pieces of research in this area was done by Dr John Hutton, a paediatrician and clinical researcher at Cincinnati Children's Hospital in the United States.

He took scans of brain activity in children aged three to five, while they were reading e-books and printed books, to understand what is really going on in a child's brain when engaging with these different types of books.

Dr Hutton and his colleagues did MRI scans of preschool-age children while presenting five-minute stories in different formats by the same author.

For the printed book, children listened to the story being narrated while big pictures were projected on the screen. The child was then told the same story in e-book format, with a fully animated cartoon and narration.

While using the e-book with animation, the brain scans of the children presented a striking drop in overall connectivity among different parts of the brain.

The scans also showed the children struggling to keep track of what was happening in the fast-moving animation.

Dr Hutton concluded that reading printed books was better, as the scans showed a balanced integration of the visual networks and the language networks.

He explained that printed books with pictures help to develop the "mental muscles" in a child, by allowing him to form mental images and reflect on a story's meaning.

With e-books, too much exposure to animation tends to shut down the networks, as the images move too quickly.

"When parents show them a video of a story, that short circuits the process - the child does not have to imagine the story - it's being fed to them," said Dr Hutton.

He also pointed to various other studies and concluded that reading to a child from an electronic device undercuts the dynamic that drives language development.

Some call this the "serve and return" model of interaction between a parent and a child. This takes place when a parent reads a book with a child - turning pages, pointing at pictures, talking about the story.

Dr Hutton noted that those things are lost when parents use an e-book.

Apart from developing reading abilities, "serve and return" also develops reasoning, thinking and even creativity in a child.

Reading experts also note that as technology evolves, publishers are adding bells and whistles, including music and games to e-books, that encourage detours. This can be counter-productive.

In a 2013 Temple University study in the US, researchers found that children aged from three to five had lower reading comprehension in cases where their parents read to them from e-books than those whose parents used traditional books.

Part of the reason, they said, was that parents and children using an electronic device spent more time focusing on the device itself than on the story.

"Parents were literally putting their hands over the kids' hands and saying, 'Wait, don't press the button yet. Finish this up first'," said Dr Julia Parish-Morris, the lead author of the study in her remarks to the media.

Echoing Dr Hutton's remarks, she said parents who used conventional books were more likely to engage in what education researchers call "dialogic reading", the sort of back-and-forth discussion of the story and its relation to the child's life.

"What we're really after in reading to our children is behaviour that sparks a conversation," said Dr Kathy Hirsh-Pasek, a professor of psychology at Temple and co-author of the study.

"But if that book has things that disrupt the conversation, like a game plopped right in the middle of the story, then it's not offering you the same advantages as an old-fashioned book."

The lesson for parents is that technology is great, but it can't replace the experience kids have sharing a picture book with mum or dad, especially during the really important early years.

How can you help your child succeed in school and life? Visit the Smart Parenting microsite.