The old dictum "do as I say, and not as I do" has become more and more relevant where the use of technology is concerned. I despair that my three kids seem to have their faces permanently bathed in the light from one screen or another, yet cheerfully flit from mobile phone to iPad to laptop as I dish up supper.I'm ashamed to admit that the nine-year-old recently admonished me for sneaking a look at my phone under a restaurant table. "I sometimes think you love that thing more than you do me," she complained.It's not a good feeling to be caught. What is worse is that these double standards amount to more than hypocrisy: parents like me are teaching our children by example that there really is no off-switch.Data from research specialist Childwise reveals that by the age of seven many youngsters will have spent what equates to one full year in front of a screen, rising to three by adulthood.A Channel 4 News poll found that almost half of parents admitted their children spend too much time in front of a screen, with 43% saying this amounts to an emotional dependency.Child health education specialist Aric Sigman urged head teachers attending the Mental Health in Schools conference in London to intervene. He warned that screen misuse in the home can have such an impact on the mental health of our children, and their ability to learn, that it is fast becoming schools' business.Richard Graham, consultant child and adolescent psychiatrist, agrees. He launched the UK's first tech addiction clinic for young people at London's Nightingale Hospital in 2010, and believes parental fixation with technology could have a greater impact on children's development than their own use does."I speak to head teachers who say they wish they could ban parental use as much as pupils'," he says. "The child comes out of school at home time, in a great rush of excitement to see their parents and tell them all about their day. But they land in front of whoever is picking them up and instantly find themselves vying for attention with a mobile phone."Frankly, if parents don't get a grip on this, then how on earth can they expect their children to?"We can't demonise the use of technology - it is crucial in modern education. The bulk of my youngest's mathematics homework is now done online and she is often told to research topics via the internet.David Holmes, senior psychologist at Manchester Metropolitan University, agrees with Sigman: we must lead our children to better tech discipline by our own example."We have to police both their use of technology and our own until a healthier relationship is instilled," he says. "That means switching off notifications so we can remain task-focused in front of them - and getting out of the habit of checking Facebook ourselves every 15 seconds."Looking over their shoulder to make sure that they are viewing relevant material is also not only acceptable but crucial - whatever objections they raise. "That way you know they aren't tackling algebra on the laptop at the same time as participating in a group iMessage on their phone," says Holmes. "And take the thing away every time they break the rules until they realise the only way forward is to stop doing it."That was my approach with my eldest, now studying for her degree. And it worked - in adulthood she turns her phone off whenever she works to avoid distraction. In fact, I would do well to follow her example instead of demonstrating a Pavlovian response to every phone alert, no matter how important the work - or the time with my kids - happens to be...