Figure 1.

Study protocol and behavior paradigm. A, Study protocol. Left, Sleep-rested session, including an 8 h sleep opportunity monitored by 19 channel with an initial testing session at ∼1000 h. Right, Sleep deprivation and recovery conditions. Deprivation testing was performed following 24 h of continued wakefulness (∼0600 h). Later that same day, following a 90 min nap opportunity monitored by 128 channel high-density polysomnography, recovery testing was performed at ∼1200 h. The order of the rested and deprivation/recovery conditions was counterbalanced across participants and separated by at least 1 week of sleep at home. B, Representative trials from the Mnemonic Similarity Task demonstrating repeated items (e.g., the baseball), lure items (e.g., the rubber duck), and new items (e.g., the rope and the first presentation of the baseball and rubber duck). Each task version consisted of unique stimuli, and the three versions were counterbalanced across both participants and protocol conditions. Correct responses are shown here in red for illustrative purposes.