Pabulum and its synonym pablum are unusual words which have vastly different (and potentially contradictory) meanings, depending on the context.
Pabulum is a Latin word which means "foodstuff." Pablum is an abbreviated form of the word, which is the trademarked name for a type of baby food.
So if you see "Pablum" instead of "pabulum," there's a good chance it may be referring to this particular type of baby food.
So how is the word "pabulum" used? Well, if you consult a medical dictionary, you will find that it refers to a type of food which can be eaten with very little effort--a suspension of nutrients in a liquid.
Hmm...sounds a bit like baby food.
Outside the medical world, pabulum can have the meaning "intellectual nourishment," and this is where the definitions can get contradictory.
Technically, pabulum is a good thing; intellectual nourishment is a very positive thing. But the word has taken an interesting spin over time; since pabulum is food designed to be taken passively rather than actively, the usage of the word has eventually come to mean "infantile intellectual nourishment." In other words, not very intellectual at all!
Most usages of the word "pabulum" today have taken on this tongue-in-cheek, ironic meaning. If someone says, "Most of the news programs on television are pabulum," they are not saying that the news provides intellectual nourishment; they are saying it is bland and infantile, and provides little to no intellectual nourishment.
It reminds me of what the Apostle Paul said in the book of I Corinthians: "I have fed you with milk, and not with meat: for hitherto ye were not able to bear it, neither yet now are ye able." (I Corinthians 3:2). Basically Paul is saying, "I'm stuck feeding you pabulum, because you're not ready for anything more profound."