A study (#1244) that will be presented later this morning as an oral presentation suggests that sleep preserves in long-term memory only what is emotionally important and relevant to future goals.
Results show that the placement of sleep is critical for remembering the components of emotionally negative scenes, but it does not impact memory for neutral scenes. Emotional items are selectively remembered 24 hours and 4 months later, but only if sleep comes soon after learning.
Find out more about theories describing the role of sleep in memory on the Sleep Education Blog.
You can download the SLEEP 2009 abstract supplement as an 11 MB file in PDF format.