TORONTO -- They're among the questions often asked by parents anxious about the time children and teens spend glued to digital gadgets -- from TV and computers to smart phones and tablets:
How much screen time is too much? And is living so much in the virtual world harmful to kids' development and health?
The answer, say experts, is "it depends."
And that caveat starts with the child's age, says Matthew Johnson, director of education at Media Smarts, a Canadian organization that promotes digital and media literacy.
"The greatest concern is with very young children, so infants and toddlers," says Johnson. "Of course, they find it very absorbing. But it doesn't stimulate them in the same way ... And when it comes to this age group, there's no evidence that media can have any educational benefit."
The Canadian Paediatric Society and American Academy of Pediatrics both advise against any screen time for children under two, although the AAP is reviewing its guidelines, which will be updated in 2016.
Dr. Michael Rich, director of the Center on Media and Child Health at Boston Children's Hospital, says passive screen time displaces far more useful activities that kids under two need for cognitive development.
"Even watching the water drops running down the shower curtain while mom takes a shower is better than parking the kid in front of a television," Rich says. "Because at least they are interacting with the real world."
Rich, who has a blog called Ask the Mediatrician on the center's website, says optimal brain development for very young children requires interaction with other people and the physical world, as well as open-ended free play.
"So a blank piece of paper and a crayon is better than an iPad."
Jennifer Rollins, an Edmonton mother who blogs under the moniker Tech Mommy, recalls being in a restaurant with her then two-year-old daughter Tenesea, who was making "a ruckus."
"I ended up passing her my phone and putting an app on it, and she stayed quiet for the rest of the time," says Rollins, 39. "It was like a new soother or something."
When Tenesea was three or four, Rollins and her husband were going through a nasty separation and the iPad was a means of preoccupying her child to protect her from the sounds of her parents fighting.
"She used it a lot, probably too much," admits Rollins. "I was very pro screen time, mostly because it became like a babysitter for her when everything else was -- well, there was a lot of turmoil."
The now single mom has done an about-face. Tenesea, 7, and her sister Azalee, 3, are restricted to an hour a day to play online games or to watch age-appropriate YouTube videos.
While she believes it's important for kids to keep up with the changing technology, Rollins also tries to be a digital role model for her daughters.
"I think there were times when I tweeted at least 100 times a day. It just became an outlet, an escape. And now maybe I tweet six times a day. I try to put my phone down as much as I can to try to give my kids more face-to-face time, to really be there for them."
What parents model for children of any age has a huge impact, agrees Rich.
"So if we are busy doing the CrackBerry prayer, as I call it, they're looking at us all the time to see how to behave in the world, to see how people function," he says.
"So one of the things I'm seeing is not just kids being pacified by these devices, but parents pushing the kid in the playground on the swing and looking at their device and texting the whole time -- not connecting with their child."
Texting while breastfeeding -- or "brexting" -- is another missed opportunity, he says.
"This is bonding. This is the gaze of mother and child. And if that gaze is directed to a Facebook page ... you're giving away that time, you're giving away that attention."
That's not to say Rich is anti-technology -- far from it.
Both he and Johnson say children from pre-school age to adolescence can benefit from online content, particularly if it's educational.
"In some ways, digital media provides opportunities that didn't exist before," says Johnson. "When we use it properly and when we encourage kids to use it properly, it's really valuable."
Rich says there is no easy answer to how much screen time is too much, and parents should understand that digital devices are tools -- tools that do some things well and others less well.
"An iPad is a wonderful way for a child to see what it's like to be on the top of Mount Everest ... but it is not the best tool for drawing, for example.
"So first of all look at the task you're asking of it and say 'Is this the best tool for the job?"'
Parents should also sit down with children over age five and together set screen-time limits around other priorities: homework, physical activity, socializing, and adequate sleep, Rich says.
"That takes the parents out of the role of police officer around media and turns them into helping the child with air traffic control. The child is still the pilot of the plane, but they are helping them take off and land safely."
For adolescents, screen media provide "a very fertile environment" for some of the key tasks they need for development, which is gaining experience, he adds.
A parent's responsibility is not to block children and teens from using the devices, but to help them process the content, he says.
"Instead of looking at the television, the computer or specific apps like Facebook as vectors of good or evil, we need to understand that they are the environment in which children are living and growing up and we need to treat them more like the air they're breathing, the water they're drinking and the food they're eating.
"Because they're going to be eating and drinking it anyway."
