Figure 1.

Study design. For all encoding and restudy sessions, participants were asked to form an association between a word and image. Participants first encoded the Sleep List (blue) before sleeping overnight while polysomnography was recorded. The next morning (day 2), participants encoded a second set of word–image pairs (Morning List). After a short delay (∼2 h), participants restudied these two sets of pairs, intermixed with novel pairs (Single Study List) in the fMRI scanner. Source memory was tested immediately after the scan and after a 24 h delay (day 3).