About sleep: Your guide to a healthy sleep

By Diana Botezan

Information on the nature of sleep, main sleep disorders, insomnia and insomnia treatment, practical strategies and techniques for healthy sleep
Although sleep is very important for our physical and emotional health, we often don't give it the importance it deserves until we have problems. This book presents the most important theoretical aspects about the nature of sleep, gives a brief review of the main sleep disorders and focuses in particular on the analysis of insomnia. Practical strategies and techniques for healthy sleep are offered.

• Language: English
• Publisher: Lulu.com
• Release date: Nov 13, 2022
• ISBN: 9781470985981

Book preview

Chapter 1. About Sleep

Nature of Sleep

Although sleep is an important part of our lives, many of us don’t pay attention to it. We usually don’t try to understand the nature of sleep until we have problems. Just like humans, animals sleep (mammals, reptiles, birds). Fish, amphibians and insects don’t sleep, they just go into a resting state. Some animals sleep in short bursts, while others, like humans, prefer to sleep in a single session. Humans spend a third of their lives sleeping. Newborns sleep around 16 hours, adults around 7-8 hours and older people around 6 hours (Zimbardo & Gerrig, 2004). We all know what sleep looks like. A sleeping person has their eyes closed, usually lies down, breathes slowly, muscles are relaxed and generally lies still, although from time to time their body position changes. If you are asleep you are unaware of most things going on around you, but sleep differs from coma or fainting because sleeping people can be awakened by noises, light or touch. The operational definition of sleep is that of a natural state characterized by a reduction in voluntary motor activity, a decrease in responsiveness to stimulation and a stereotypical posture. Sleep is distinguished from other altered

ABOUT SLEEP

states of consciousness, such as coma or anaesthesia, in that it is reversible and self-regulating. Sleep is studied by recording graphical brain wave recording (EEG).

The Stages of Sleep

Researchers tell us that there are two types of sleep:

REM (rapid eye movement) sleep

When we sleep, our brain goes through several phases in a cyclical way. Some of these stages are characterized by slow brain activity and in other stages the brain’s electrical activity mimics the waking brain. This stage of sleep hyperactivity is called REM sleep and has three things that define it: The brain is more active than in other stages, alpha and beta waves are recorded, similar to wakefulness; Muscle activity is completely inhibited within the central nervous system, muscle paralysis occurs; Rapid eye movements occur during REM sleep because muscle paralysis does not extend to the eye muscles. This type of sleep occurs around 25% of the night and is characterized by electrical activation of the brain, very relaxed muscles and immobile body and rapid eye movements under closed eyelids. REM sleep energizes the brain and body and supports our daytime activities. Dreams often occur during REM sleep, although they can occur at any stage.

CHAPTER 1. ABOUT SLEEP

NREM (non-rapid eye movement) sleep

This type of sleep occurs around 75% of the night and can be divided into 4 stages. Stage 1: shallow sleep, between wakeful-ness and falling asleep; characterized by a regular pattern of 8-12 Hz (alpha waves) Stage 2: this stage represents the onset of sleep, when the person begins to become disengaged from the environment. Body temperature decreases and breathing and heart rate become regular. The second stage is characterized by the appearance of short spindles (12-16 Hz). Stages 3 and 4: These stages represent the deepest and most restful sleep, known as ‘delta sleep’. Stage 3 is a transition into stage 4 or ‘true delta’. During stages 3 and 4 of sleep, commonly referred to as deep sleep, delta waves (1- 3 Hz, also called slow-wave activity-SWA) appear in the EEG. The increase in sleep intensity is thus defined by the increase in strength, amplitude and total incidence of delta waves in the cortical EEG during NREM sleep.