In a recent report from the Kaiser Family Foundation, screen time (TV, videos, computer) easily beats out reading.
Too much TV - even of the educational type - is usually inferior to the printed word for language development.
To get an idea of the differences in new vocabulary depending on the media type, Sesame Street had 2 rare words per 1000, compared to children's books at 30.9.
In general, conventional TV language is dumbed down - primetime adult TV has 22.7 rare words per 1000, an even lower rate than children's books.
The report also noted another disturbing trend in U.S. households - 43% of children age 4-6 years had a TV in their bedroom. This usually begun so that adults could watch their programs or to help children go to sleep.
In studies of older children (Generation M), a TV in the bedroom was associated with the lowest levels of school performance and daily reading.
Media and the Preschooler
Eide Neurolearning Blog: Generation M: Report on Kids & Multimedia
Eide Neurolearning Blog: What Reading Does for the Mind - and How Gifted Dyslexics Defy the Matthew Effect
Eide Neurolearning Blog: Brain of the Blogger