The problems were seen in a study of 60 children randomly assigned to either watch “SpongeBob,” or the slower-paced PBS cartoon “Caillou,” or assigned to draw pictures. Immediately after these nine-minute assignments, the kids took mental function tests; those who had watched “SpongeBob” did measurably worse than the others.

Previous research has linked TV-watching with long-term attention problems in children, but the new study suggests more immediate problems can occur after very little exposure — results that parents of young kids should be alert to, the study authors said.