Figure 2. Set up and experimental tasks. The experiment included an ‘‘encoding’’ (ENC) and a ‘‘retrieval’’ (RET) tasks in which 50 complex colored magazine pictures were shown after a red central target given as a visual warning stimulus (presentation time of 1 s). In the ENC condition, 25 figures representing interiors of apartments (‘‘indoor’’) were randomly intermingled with 25 figures representing landscapes (‘‘landscapes’’). The figures were shown one-by-one (cue period, presentation time of 5 s). Subjects were instructed to press with right index finger one of the two close buttons (left = ‘‘indoor’’; right = ‘‘landscapes’’) as quickly as possible after the appearance of a green central target at the center of the figure (go stimulus, presentation time of 1 s). About 1 h later, the RET condition started. In this phase, 25 figures representing previously presented ‘‘indoor’’ (‘‘tests’’) were randomly intermingled with 25 figures representing novel ‘‘indoor‘‘ (‘‘distractors’’). Subjects were asked to discriminate between ‘‘tests’’ among ‘‘distractors’’ by pressing one of the two buttons (left = ‘‘tests’’; right = ‘‘distractors’’) immediately after the go stimulus. The timing of warning stimulus, cue stimulus (picture presentation) and go stimulus was as in the ‘‘encoding’’ phase.