LIFESPAN CHANGES IN SLEEP

Sleep involves being still, unresponsive (but not unconcious)..woken by significant noises e.g. parent woken by child cry --> Animals usually sleep in quiet, safe, secure place, in the dark (sleep possible in other situations i.e. sitting upright on train) Cows sleep standing up --> Wide variation in time spent sleeping - sloth 20hrs/3hrs

Varies over lifespan:

Infancy= more sleep than other ages 16hrs a day --> shorter cycle than adult which is 90mins --> 'active sleep' mainly REM --> Immature versions of SWS & REM --> adaptive for newborns to have diff. sleep cycles = help parents deal w/everyday life

Childhood= similar EEG patterns to adults, sleep more 12 hrs & more REM activity (30%) --> Boys sleep more than girls -->May occur b/c children have more SWS (OLIVIERO) --> May have genetic basis (50% concordance rate in identical twins) & gene identified w/sleep walking --> RESEARCH METHDO: Evidence biological... objective scientific evidence --> H/W often reductionist, isolating & testing only one variable involved  

Adolescence= sleep increases 9-10hrs..balance of rhythm changes: more awake at night & have more problems getting up early --> Possibly due to hormonal changes --> H/W the many factors involved .. diff. to study & thus draw concl. from this area of research --> ALSO CULTURAL DIFF. in sleep patterns of teens: Korea 6.5 , Iran 7.7 

Adulthood = 8hrs 25% in REM 'normal' --> H/W Too much sleep can increase mortality .. 10+hrs - correlational data --> H/W limitations of correlational data --> FURTHERMORE: other factors may affect old people sleep patters = physiological change, illness, probs. stayin asleep less time SWS

H/W nature of the lifespan of sleep not 'fixed' --> alcohol, caffeine, excercise affect it