BOSTON -- New research is raising questions about whether educational videos for kids really help them learn.

By the time they're 2, children watch an average of two hours per day of media. However, research on nearly 100 children between 12 and 24 months old found they do not appear to learn language skills, or words from those videos. In fact, children whose parents say they watched infant DVDs at an early age scored lower on vocabulary tests. Researchers said they don't know if the DVDS have a negative effect.

The report is published in Archives of Pediatrics & Adolescent Medicine.

Veterans With PTSD

New research offers insight into what may cause post-traumatic stress disorder in Veterans.

Researchers from the University of California, San Francisco, took brain scans of vets with PTSD. In those vets, a specific area of the brain responsible for memory was much smaller.

Researchers said this discovery could lead to better diagnosis and treatments.

Reversing Damaged Arteries

Doctor's will tell you that eating lots of high fat foods will harden your arteries. Israeli doctors now say three weight-loss diets can reverse the damage.

They randomly assigned obese men to one of three diets, and examined them after two years. They found a low-carbohydrate, low-fat, or Mediterranean diet are equally as effective in helping obese people reverse artery damage; the more weight loss the better.

The study was published in the journal Circulation.