The cartoon SpongeBob SquarePants rules the roost as the most popular television show for children between the ages of 2 and 12. But the program’s undersea mayhem may come at a cost. A study by two U.Va. researchers concluded that fast-paced, fantastical shows are not the best things for children to watch if they need to pay attention, solve problems or moderate their behavior after watching.

Those abilities, called executive functions, seemed to be impaired among 4-year-olds after watching nine minutes of SpongeBob SquarePants. That’s when compared with similar study groups: one that watched Caillou, a slower-paced, public television show, and another that spent nine minutes quietly drawing.

Immediately after the activities, 15 percent of the children who watched SpongeBob were able to pass a problem-solving task, compared with 35 percent of the Caillou watchers and 70 percent of those who drew.

Lead investigator Angeline Lillard, a psychology professor at U.Va., says the results show such TV programs may handicap youngsters’ readiness for learning. But the results don’t warrant conclusions that fast-paced shows can “harm children’s brains,” as suggested in a Bloomberg news agency story.

“If a child has watched a television show that has reduced their executive function, you can’t expect them to behave at their normal level,” Lillard says.

“We don’t know what the long-range impact is of watching shows like this on a consistent basis. But what we’re seeing over the short term is a disruption in executive function,” she says.