GA4051_2iwatch-tvA recent study from Japan found that children who watch TV a lot have more gray matter than kids who don’t watch TV. But, the researchers warn, that is not necessarily a good thing.

The study looked at brain scans of kids between the ages of 5 and 18 and found that the more TV they watched, the bigger their brains were in certain areas in the front and side of the head. However, the kids with more brain volume were also found to have lower IQ scores. What can explain that?

According to Hikaru Takeuchi, a researcher involved in the study, some brain areas are meant to shrink during childhood in a process of pruning, that makes the brain operate more effectively. He notes, “Gray matter volume is like body weight,” His meaning: gaining muscle in the body is generally a good thing, but gaining a lot of fat is not. These increases in brain volume may be like the brain “getting fat.”

To learn more, you can check out the study abstract in Cerebral Cortex or read a detailed article from the Washington Post.