Sleep

Question 1

Sleep

Answer 1

is an ASC that features the suspension of awareness of the external environment and is accompanied by a number of physical changes to the body. It is brought on by the hormone melatonin. It is a circadian rhythm (occur every 24 hours).

Question 2

Survival adaptive theory explanation

Answer 2

This theory suggests that we have periods of inactivity, or sleep, when we do not need to engage in activities important to our survival, and animals that are sleeping are less likely to be attacked

Question 3

Sleep adaptive theory evidence

Answer 3

Animals that have few physical need sleep for longer than animals with greater physical needs

Question 4

Sleep adaptive theory criticism

Answer 4

One of the activities necessary for survival is the simple act of staying alive. Because of this small animals stay awake to be on alert for predators

Question 5

Restorative theory explanation

Answer 5

A theory that states that sleep is vital for replenishing and revitalising the mind and body to keep them functioning at optimum levels

Question 6

Restorative theory evidence

Answer 6

Research shows that following vigorous activity there is an increase in NREM sleep as the body needs replenishing

Question 7

Restorative theory criticism

Answer 7

The brain is active during dreaming when it is supposed to be conserving energy. Non-active people experience the same amount of NREM as active people

Question 8

Awake and alert stage of sleep

Answer 8

This is when the brainwave activity consists of beta waves, short (low amplitude) and fast (high frequency).

Question 9

Awake and drowsy stage of sleep

Answer 9

Brainwaves patterns are predominately alpha waves which are slower (lower frequency) and bigger (high amplitude) than beta waves.

Question 10

NREM Stage 1

Answer 10

· Light sleep – Drift in & out of sleep, but still aware of some sounds in the environment. - Hypnogogic stage - Can experience hallucinatory images · Brain waves: Alpha waves decrease & theta waves start to appear (medium frequency, high/low amplitude). · EOG: slow, rolling eye movements. · Physiological changes: Heart rate slows, breathing slows, body temp decreases & muscles relax. Sometimes a hypnic jerk occurs (muscle spasm). · If woken, people might report that they weren’t asleep. · Duration: 5 – 10 minutes

Question 11

NREM Stage 2

Answer 11

· Person is truly asleep, but can be easily roused. · Brainwaves: Theta · Sleep spindles: Sudden brief bursts of high frequency brain wave for about 1 sec. · Indicates person is actually asleep. · K-complexes: Single, large bursts of high amp. & low frequency occurs in response to arousing stimuli. · About halfway through stage 2 we are unlikely to respond to anything except extremely strong, or loud stimuli, indicating deep sleep. · EOG: Eye movements are rare · Physiological changes: Body temp, heart rate, blood pressure & body movement all decrease. Duration: 10 – 20 minutes.

Question 12

NREM Stage 3

Answer 12

· Moderately deep sleep · Very relaxed & less responsive to outside world. · Brain waves: Mix of theta waves (80%) & delta waves (20%) but increasing. · EOG: Eye movements are rare. · Physiological changes: Heart rate, blood pressure & body temp continue to drop. · If woken, difficult to rouse & may be groggy. - Together with stage 4 = slow wave sleep Duration: 10 minutes (varies)

Question 13

NREM Stage 4

Answer 13

· Very deep sleep (50% delta waves). · Physiological changes: Muscles completely relaxed, breathing & heart rate are slow & regular, lowest body temperature. · Very hard to wake person & they may be disoriented & confused (sleep inertia). · Duration: 20 minutes (varies). Combined with stage 3 is 30 minutes, this decreases as the night progresses until one doesn’t reach stage 3 or 4. · Progression through the NREM sleep cycle from stage 1-4 takes about 45-60 minutes before we progressively movement back up stages 3,2,1. Somanambulsim likely in 7% of kids, 2% adults Sleep talking can occur in any stage, but more common in NREM

Question 14

REM Sleep

Answer 14

• 1st cycle lasts about 10 minutes, time gradually increases with each cycle - lighter sleep, easier to wake from - EEG patterns look awake - beta-like waves, sawtooth waves may occur during burst of rapid eye movement - body temp matched surrounding environment - genitals aroused - muscle atonia occurs (paralysis) also known as cataplaxy - dreams occur in REM (NREM only 10% of time, more difficult to remember) last dream best