Giving Compass' Take:

• Jean Twenge, professor of Psychology at San Diego State University, explores the link between smartphone use and sleep deprivation in this article from The Conversation.

• The author compares criticism of smartphones today to concerns about television and rotary phones in the 1970s and 1980s. Are today's concerns more justified? Should mental health advocates focus on the consequences of excessive smartphone use?

• For more on screen time and cognitive development, click here.

Parents who fear their kids are spending too much time in front of screens now have more reason for concern. New research funded by the National Institutes of Health found brain changes among kids using screens more than seven hours a day and lower cognitive skills among those using screens more than two hours a day.

It almost goes without saying that today’s portable devices – including smartphones and tablets – are fundamentally different than the living room television sets and rotary phones of the past. Since researchers have been tracking TV watching habits, the average U.S. teen has never spent more than two-and-a-half hours a day watching TV. Yet as of 2016, the average teen spent about six hours a day immersed in digital media – more than twice as much time.

Kids and teens who spend more time with screens – including both TV and portable devices – also sleep less. That could be because they spend so much time engaged with their devices that it’s coming at the expense of sleep. But there’s also a physiological reason: The blue light emitted by electronic screens tricks our brains into thinking it’s still daytime, and then we don’t produce enough of the sleep hormone melatonin to fall asleep quickly and get high-quality sleep.

So what is a parent – or anyone who wants to sleep well – to do?

First, it’s best for smartphones and tablets to stay out of the bedroom after “lights-out” time. Nor is it a great idea to use the devices within an hour of bedtime, as their blue light influences the brain’s ability to produce melatonin. Finally, as a general rule, two hours a day or less spent on portable devices is a good guideline. These rules apply to parents, too – not only kids.

Read the full article about smartphone use by Jean Twenge at The Conversation