Sleep theory + hygiene

Restorative theory

States sleep allow recharge body, recover from physical + psychological work in day + allows body’s growth process to occur
-repair + replenishes the body (NREM)
-enhances mood

activates growth hormone, responsible for physical growth, esp N3
↑ immunity to disease, immune cells = replenished in sleeping.
↑ alertness, consolidates memory (REM)

Restorative theory criticisms

Assumption more sleep = needed to recover when physically active.
Evidence = people physically disabled / confined to bed do not require less sleep than active person

Assumption body rests in sleep, but brain = active during sleep
-↑ blood flow + energy expenditure in REM

Survival theory
-means of increasing an animal’s chances of survival in its environment

Sleep is adaptive,, change + meet demands of environment

Sleep requirements = evolved over time 4 species hunt food, hide + conserve energy
-evolved to enhance survival of organism by making it inactive in most vulnerable time day

Sleep theory what it does

Depends on need to find food e.g sleep less for more food

Depends on animal’s vulnerability to predators
-small preys = sleep ↑ to hide, large = sleep ↓ as more exposed

Sleep conserves energy (hibernating in winter, food + weather harsh)

Criticisms

Assumption that sleep = useful, not essential.
-all species sleep, despite amount of food / danger.

Assumption sleep = hide from predators. Loss of awareness in sleep = the vulnerable to risk, but biologically compelled to sleep

Sleep hygiene

Sleep hygiene practices = improve sleep + maintain good sleep + daytime alertness

-avoid stimulating activities, naps
-improve sleep environment - not too hot, too cold, dark, control loud noise
-digesting food = disruptive b4 sleep
-exercise

Zeitgebers - Temperature
-falls in night, rises in day

External environmental cues, synchronize circadian rhythms w/ 24hr cycle

Temp = circadian rhythm, follows 24hr sleep wake cycle
-sleep = more likely when temp ↓
-2 hr b4 sleep, temp ↓, bedroom temp = act as zeitgeber, cool not hot