Nonmedical use of psychostimulants for cognitive enhancement is widespread and growing
in neurotypical individuals, despite mixed scientific evidence of their effectiveness. Sleep …

Study objectives Consumer sleep trackers issue daily guidance on 'readiness' without clear
empirical basis. We investigated how self-rated mood, motivation, and sleepiness (MMS) …

Why should researchers measure psychophysiological processes repeatedly over time?
The study of psychophysiology inherently involves sampling biological processes as they …

Objectives Abundant research has linked nightly sleep as an antecedent of daily
psychosocial experiences; however, less is known about sleep's influence on daily …

Sleep is both a neurophysiological state and a biologically necessary behavior that performs
a variety of indispensable roles for human health, development, and cognitive functioning …

Background Sleep is an important factor in well-being, especially during the transition to
college when academic and social commitments increase. Identifying factors that contribute …

Objective We sought to test the effects of different duration naps on post-nap cognitive
performance during simulated night shifts. Methods We used a randomized laboratory …

Pre-sleep affect is thought to influence sleep, but associations with both sleep architecture
and the electroencephalographic (EEG) power spectrum are mixed. In this pre-registered …

Recent research highlights a variety of negative outcomes associated with intraindividual
variability in positive affect (PA) and in sleep. Thus, this study examined the associations of …

Abstract Study Objectives Current evidence suggests that cortisol levels are bi-directionally
associated with sleep. However, the daily, naturalistic cortisol-sleep associations remain …