Reduced slow-wave rebound during daytime recovery sleep in middle-aged subjects.

Cortical synchronization during NREM sleep, characterized by electroencephalographic slow waves (SW <4 Hz and >75 µV), is strongly related to the number of hours of wakefulness prior to sleep and to the quality of the waking experience. Whether a similar increase in wakefulness length leads to a comparable enhancement in NREM sleep cortical synchronization in young and older subjects is still a matter of debate in the literature. Here we evaluated the impact of 25-hours of wakefulness on SW during a daytime recovery sleep episode in 29 young (27 y ± 5), and 34 middle-aged (51 y ± 5) subjects.

Aging worsens the effects of sleep deprivation on postural control.

Falls increase with age and cause significant injuries in the elderly. This study aimed to determine whether age modulates the interactions between sleep deprivation and postural control and to evaluate how attention influences these interactions in the elderly. Fifteen young (24±2.

Effects of increased homeostatic sleep pressure on postural control and their modulation by attentional resources.

Objective: This study aimed to determine how increased sleep pressure interferes with postural control according to the availability of attentional resources and visual input.

Methods: Thirteen healthy young adults performed a psychomotor vigilance task and postural tasks after a night of sleep and after 25 h of sleep deprivation. Primary outcome variables were calculated from the center of pressure (CoP) displacement measured by two force plates in various cognitive load and visual state conditions.

Sleep deprivation increases blood pressure in healthy normotensive elderly and attenuates the blood pressure response to orthostatic challenge.

Study Objectives: To determine how aging affects the impact of sleep deprivation on blood pressure at rest and under orthostatic challenge.

Design: Subjects underwent a night of sleep and 24.5 h of sleep deprivation in a crossover counterbalanced design.

Sleep slow wave changes during the middle years of life.

Slow waves (SW; < 4 Hz and > 75 μV) during non-rapid eye movement (NREM) sleep in humans are characterized by hyperpolarization [surface electroencephalogram (EEG) SW negative phase], during which cortical neurons are silent, and depolarization (surface EEG positive phase), during which the cortical neurons fire intensively. We assessed the effects of age, sex and topography on the dynamics of SW characteristics in a large population (n=87) of healthy young (23.3 ± 2.