On Dreams

There was an article in the Science section of the New York Times about how dreams appear two ways.  First, they might appear as the result of a day's emotional events.  Second, though, there is almost a "rerun" effect.  They'll "play," if that's the right word, a week or so later.   Here's a link to the article:
http://www.nytimes.com/2010/09/07/health/07really.html?ref=science