Does TV make you hyper? dumb? lazy? distracted? What was the question?

Jim Schnabel has an interesting story at Nature, free to all viewers, on the tetchy difficult of assessing how TV affects kids. I've often wondered whether the rise in ADHD diagnoses was due at least partly to TV. This story looks at a researcher who -- amazed at how riveted his infant son was by TV -- found this seems to be the case.

Christakis decided to try to address these questions with research. Together with several colleagues, he examined a database called the National Longitudinal Survey of Youth. After analysing some 1,300 children for whom the appropriate data were available, they found that on average, a child who had watched two hours of television per day before the age of three was 20% more likely to have attentional problems at the age of seven, compared with a child who had watched none.

That was back in 2004, in a study in Pediatrics. Christakis then did a follow-up, drawing on a different long-term sample, showing that

the link to later attentional problems was particularly strong for cartoons and other entertainment programmes watched before the age of three. For educational programs, such as the gently paced US series Mister Rogers Neighborhood, they found no such link.

(Mister Rogers. Man could do no wrong.)

Sounds pretty conclusive, no? But the story goes on to describe how foggy and inconclusive the research on TV is -- partly because too few studies get follow-up, and because funding them is surprisingly difficult. The logical problems are pretty complicated. And in addition, any talk of regulating TV content -- or even studying the facts -- runs into freedom of speech issues.

Nevertheless, Christakis was able to get a media effect study funded by the NIC HD, and is just starting it now. It will look at the effects of changing TV content on preschool children, rather than effects of eliminating such content. Mr. Rogers versus ninja turtles if you will. That said, Christakis's stopped his own kids from watching TV until the age of two; I myself can't bear the thought of my kids watching any regular TV programming; we don't get cable, have never missed it (well, okay, I miss it during the baseball playoffs), and the kids get by with Charlie and Lola and David Attenborough.

In any case, it figures that TV, being such a powerful, ubiquitous, and fairly unique medium -- especially if you go heavy on the fast-paced stuff -- has to have a particular effect on kids' brain development. A couple weeks ago I was at the lab of NIH researcher Doug Fields, who has shown that myelin -- the fatty coating over axons that helps determine the speed, coordination, and effectiveness of the brain's networks -- is laid down and modified, primarily during childhood and adolescence, very much in response to experience. If TV is a big part of that experience -- and it is, for most American kids -- then it is presumably driving a lot of the brain's wiring.

This Nature story is a nice look at the state-of-the-art of TV research. Definitely worth a look, from the comfort of your own chair.

television, media, ADHD, research, attention, media