CHAPTER 4; SLEEP Flashcards
What is REM sleep?
Rapid eye movement sleep, one of the two stages of sleep.
What is NREM sleep?
Non-rapid eye movement, one of the two stages of sleep. It is broken down into stages; 1, 2, 3 and 4.
What is Somnamblism?
Sleepwalking.
What are Night terrors?
Extremely frightening episodes where a person wakes, often screaming, in sheer terror. Usually the person does not remember their night terror. They occur in stages 3 and 4 NREM sleep, a time when voluntary muscles are relaxed but still able to move.
What are Nightmares?
Unlike night terrors, nightmares are more usually remembered, and occur in the first 2 sleep cycles (early in the night) in stages 3 and 4. Nightmares occur in REM sleep.
What is Muscle atonia and Cataplexy?
The paralysis in REM sleep. There is no muscle tension, and the muscles that move voluntarily, especially those below the neck, are very relaxed to the point of being almost paralysed (except for the occasional twitching).
What are K-complexes?
Sharp rise and fall in amplitude, lasting for about two seconds.
What are Sleep spindles?
Periodic bursts of rapid frequency.
What are Sawtooth waves?
Random, fast waves that are slightly bigger than alpha waves. They resemble waves for being awake but occur among the beta-like waves during REM sleep.
What are Beta Waves?
High frequency (fast - up to 40 per second) and low amplitude (small). Typical brainwave pattern during NWC, associated with being alert, active, anxious and paying attention. Eyes are open, person is awake and alert.
What are Alpha waves?
Reasonably high frequency (not as high as beta waves) and low amplitude (slightly higher than beta waves). Typical brainwave pattern when awake but very relaxed, such as while daydreaming, very drowsy or when you are about to fall asleep. Eyes are often closed.
What are Theta waves?
Medium frequency and mixed amplitude (some high, some low). Typical brainwave pattern during early stages of sleep. Also seen in young children and psychopaths, may be caused by frustration.
What are Delta waves?
A steady pattern of low frequency (slow 1 to 4 per second) and high amplitude (large). Typical brainwave pattern associated with NREM deep sleep. Also mainly seen in babies and adults with brain tumours.
What is the Hypnogogic state?
Occurs during the transition from being awake to being/falling asleep. We become very relaxed.
What are Hypnogogic (hypnic) jerks?
Involuntary muscle twitches that cause us to jolt.
What is the Survival (adaptive and evolutionary) theories of sleep?
According to the Survival theories, survival is the main purpose of sleep. It also believes;
- Sleep is a means of increasing an animal’s chances of survival in its environment,
- Sleep depends on the need to find food,
- Sleep depends on an animals vulnerability to predators, and
- Sleep conserves energy.
What are criticisms of the Survival theories?
- The assumption that sleep is very useful but not essential. This theory does not explain why we must sleep.
- The assumption is that sleeping is a way to hide safely from predators. For animals that are highly preyed upon, sleeping can be dangerous, because we lose awareness when we sleep.
What is the Restorative (restore and recover) theories of sleep?
According to the Restorative theories, sleep allows us to recharge our bodies, recover from the physical and psychological work during the day and allows our bodies’ growth processes to function. It also believes;
- Sleep repairs and replenishes the body and prepares it for action the next day,
- Sleep enhances mood,
- Sleep activates growth hormone,
- Sleep increases immunity to disease,
- Sleep increases alertness, and
- Sleep consolidates memories.
What are criticisms of the Restorative theories?
- The assumption that more sleep is needed to recover when we are physically active.
- The assumption that the body rests during sleep.
