MONDAY, Sept. 12 (HealthDay News) -- Fast-paced TV shows like "SpongeBob SquarePants" seem to negatively affect children's concentration levels shortly after watching them, while slower-paced shows don't, a new study suggests.

"We found that young children who had just watched 'SpongeBob SquarePants' were handicapped in what you could say is their readiness for learning," said lead researcher Angeline S. Lillard, a University of Virginia psychologist.

"This included their ability to think and concentrate," she said.

Lillard added that this effect is not confined to "SpongeBob SquarePants," a cartoon set beneath the sea. "We have replicated this now with another fast-paced fantastical show," she said.

Lillard said she got the idea for the study while watching "SpongeBob SquarePants" in anticipation for using it for a different study. "I found it difficult to think after having watched episodes of it for an hour," she said. "That's what inspired me to do the study."

For children, such fast-paced, bizarre programming may be too taxing for their developing brains, Lillard said.

"When children have to process a lot of information very quickly, it is difficult to process because it's unusual. In this case [SpongeBob episodes] a lot of things are happening that can't happen in real life," she explained. "We think it leaves them mentally exhausted -- at least for a short time."

How long these effects might last isn't known, Lillard added. "We don't know if these effects build over time and create long-term attention problems, but we do know at least immediately afterward they are compromised in their ability to function," she said.

There have been other studies that show a connection between television watching and attention problems later in life, Lillard noted.

For the study, published online Sept. 12 in the journal Pediatrics, Lillard and her colleague, Jennifer Peterson, divided sixty 4-year-olds into three groups. One group watched nine minutes of "SpongeBob SquarePants," another group watched nine minutes of the slower-paced public television children's show "Caillou," and the last group spent nine minutes drawing.

The children were then given four tasks designed to measure what is called the "executive function" of the brain. The tasks included delay-of-gratification where the children had to wait for rewards, and a mathematical puzzle game called Tower of Hanoi, which requires children to move disks from one peg to another. The tests measure concentration, memory and learning, Lillard said.

The children's parents also were asked what programs their kids regularly watch and how much.

The children who watched "SpongeBob SquarePants" did significantly worse on the tasks than the children who watched the PBS program or drew. This finding held true even after taking into account how much TV a child typically watched, the researchers said.

Lillard advises parent to keep a careful eye on their child's behavior after watching fast-paced cartoons. "See if the child is having difficulty functioning at their normal level. If they are, they [parents] should be careful when they allow their children to watch such shows," she said.

Dr. Dimitri A. Christakis, George Adkins Professor and director of the Center for Child Health, Behavior and Development at the University of Washington and author of an accompanying journal editorial, called the study a "significant contribution to our knowledge of the effects of media on children."

"It is not all television that's bad, it's certain features of the medium that have potential adverse effects on children," he said. "Parents need to focus as much on the content and quality of the show as on the quantity."

Christakis said the young, developing mind can be overstimulated. Human brains aren't designed to process things at the speed at which they sometimes occur on TV, he said.

"Everything our brains evolved to deal with takes place in real time," Christakis said. "It's not that we can't process these shows, we do, but it may come at a cost -- a short-term cost, so we can't concentrate immediately afterward."

And, he added, "potentially a long-term cost as you condition the brain to expect that high level of input, which makes the real pace of the world seem boring and that leads to attentional problems later in life."

More information

For more on media and children, visit the Center on Media and Child Health.