SLEEP THEORIES SLEEP DEPRIVATION GOING WITHOUT SLEEP PARTIAL

SLEEP THEORIES

SLEEP DEPRIVATION GOING WITHOUT SLEEP PARTIAL SLEEP DEPRIVATION – less sleep than normal Effects – tiredness, lack of energy, lapses in attention TOTAL SLEEP DEPRIVATION - No sleep at all Effects – anxiety disorders, hallucinations, paranoia. Prolonged sleep deprivation can lead to impaired functioning of the immune system (Coren)

SLEEP DEPRIVATION TOTAL SLEEP DEPRIVATION RESULTS IN: PSYCHOLOGICAL PHYSIOLOGICAL Anxiety Disorders Hand tremors Depression Drooping eyelids Hypertension Difficulty focusing the eyes Sleep Disorders Lack of energy and strength Hallucinations (false perceptions) Slurred speech Delusions (false beliefs) Increased sensitivity to pain Paranoia Heart rate and body temperature drops Impaired functioning of immune system It is difficult to judge if a person has total sleep deprivation due to microsleeps This is a very short period of drowsiness or sleeping that occurs when the person is apparently awake

THE PURPOSE OF SLEEP There are many different theories about why we sleep. These theories include: RESTORATION & SURVIVAL

THE PURPOSE OF SLEEP RESTORATION RESTORATIVE THEORIES OF SLEEP (Recovery theories/Restore & Recovery Theories) These theories propose that sleep provides ‘time out’ to help us recover from depleting activities during waking time that use up the body’s physical and mental resources NREM SLEEP REM

THE PURPOSE OF SLEEP RESTORATION –NREM SLEEP REM REBOUND People in sleep laboratories were regularly woken when they began REM sleep. Researchers found that when they were allowed to sleep again, they spent longer in REM sleep than they normally would.

THE PURPOSE OF SLEEP SURVIVAL THEORIES OF SLEEP (Meddis) (Adaptive Theories/Evolutionary Theories/Preservation & Protection Theories) These theories propose that sleep evolved to enhance survival by protecting an organism through making it inactive during the part of the day when it is most risky and dangerous to move about (Meddis, 1977) EVIDENCE: Animals with few natural predators sleep for longer periods of time Animals with many natural predators sleep for shorter periods of time We sleep at night because we need light to see

EVALUATION Survival theories do not explain why sleep involves a loss of awareness, since the loss of consciousness during sleep may place the organism at greater risk. Limited evidence for the survival theories – but they do provide insights. Overall – sleep has multiple purposes – two of which are restoration & survival.