Figure 1.

Experimental Design and Behavioral Results

(A) Participants performed a vocabulary-learning task in the evening. They learned to associate Dutch words (cues) with German words (targets). After the initial learning phase, a cued recall, including feedback, was performed (recall1). Afterward, the cued recall was repeated without feedback (recall2). Subsequently, participants slept for 3 hr. During NREM sleep, 80 Dutch words (40 cued and 40 cued + feedback) were repeatedly presented. Memory performance was assessed in the final retrieval phase after sleep

(B) Presenting single Dutch word cues during NREM sleep enhanced memory performance as compared to word-pair TMR and uncued words. Retrieval performance is indicated as percentage of recalled words, with performance before sleep set to 100%.

Values are mean ± SEM. ^∗∗p < 0.01.