Fig. 5.

Experimental paradigm. On day 1, subjects were instructed to memorize 320 randomly selected photographs (i.e., “remote”). After the subsequent rest/nap, they studied 80 new photographs (i.e., “recent” of day 1) before scanning. During scanning, subjects performed a recognition memory test on randomly intermixed 80 remote, 80 recent, and 80 new photographs with three response options: (i) picture seen before with confidence, (ii) picture less certain to be seen before or not, and (iii) picture not seen before with confidence. This sequence of prescan study phase of new photographs and recognition memory test in the scanner was repeated on days 2, 30, and 90.