Subjective sleepiness (KSS) scores (left) and self-relevance scores for the stimuli (right).

<p>NAME: name condition, Inv-NAME: inverted name condition, BEEP: beep condition. Cont: control condition, KSS: Karolinska Sleepiness Scale.</p

Schedule of the experiment.

<p>NAME: name condition, Inv-NAME: inverted name condition, BEEP: beep condition. Cont: control condition, KSS: Karolinska Sleepiness Scale, PVT: psychomotor vigilance test. In the stimuli epochs, a stimulus was presented every 20 s. The order of the condition was counterbalanced among the participants.</p

Spectral power densities in alpha (left) and theta (right) band frequencies.

<p>NAME: name condition, Inv-NAME: inverted name condition, BEEP: beep condition. Cont: control condition, KSS: Karolinska Sleepiness Scale. The data shown are subtracted values from the Cont condition.</p

Lapses (left) and reaction times (right) in the psychomotor vigilance test.

<p>NAME: name condition, Inv-NAME: inverted name condition, BEEP: beep condition. Cont: control condition, PVT: psychomotor vigilance test, RRT: reciprocal reaction time. The data shown are subtracted values from the Cont condition.</p

Median of the reaction time in the psychomotor vigilance test.

<p>Median of the reaction time in the psychomotor vigilance test.</p

Sleep architecture in the PER+Nap and NoPER+Nap conditions.

<p>Sleep architecture in the PER+Nap and NoPER+Nap conditions.</p

Design of the experiment.

<p>Three experimental conditions were carried out: (1) perturbation and nap (PER+Nap), (2) no-perturbation and nap (NoPER+Nap), and (3) perturbation and rest (PER+Rest). In the PER+Nap condition, participants conducted the visuomotor task with perturbation caused by the axis rotation of the mouse. After the task, participants took a 90 min nap. In the NoPER+Nap condition, participants conducted the visuomotor task without perturbation and then took a nap. In the PER+Rest condition, they conducted the perturbation task and instead of a nap they took a 90 min break.</p