SpongeBob SquarePants, a popular children's cartoon, can be hazardous to children's health.

The study from the American Academy of Pediatrics is arguing that fast-paced shows like the popular Nickelodeon cartoon aren't good for children.

For the moment, Nickelodeon has released a statement questioning the validity of the study.

The 4-year-olds who viewed the fast-paced cartoon and then took the tests, ''were handicapped in their readiness for learning, says researcher Angeline Lillard, Ph.D., professor of psychology at the University of Virginia, Charlottesville.

Lilliard randomly assigned sixty boys and girls who were 4-years-old to one of the three groups. The first group watched the fast-paced cartoon program about an animated sponge that lives under the sea. The second group watched a slower-paced educational cartoon that showed a typical U.S. preschooler. And the third group drew with crayons and markers.

Right after the viewing, the children were given a variety of tests to assess their attention, problem-solving ability and other skills. In one test, the researchers measured their ability to delay gratification by seeing if they could hold off on eating snacks. In another, they measured problem-solving abilities by asking children to move disks from one peg to another.

The kids who viewed the fast-paced cartoon show did worse than the other two groups on the tests.

Those who watched the cartoon program were also less able than the others to delay gratification and follow directions.

The study has limitations, including its small size.

Lillard, the lead author, said Nickelodeon's SpongeBob shouldn't be singled out. She found similar problems in kids who watched other fast-paced cartoon programming.