Offbeat Tuesday

When its this hot I have troubles sleeping. So this weeks topic includes facts about sleep.

-The record for the longest period without sleep is 18 days, 21 hours, 40 minutes during a rocking chair marathon. The record holder reported hallucinations, paranoia, blurred vision, slurred speech and memory and concentration lapses.

- It's impossible to tell if someone is really awake without close medical supervision. People can take cat naps with their eyes open without even being aware of it. Yeah baby...that's me!

- Anything less than five minutes to fall asleep at night means you're sleep deprived. The ideal is between 10 and 15 minutes, meaning you're still tired enough to sleep deeply, but not so exhausted you feel sleepy by day.

- A new baby typically results in 400-750 hours lost sleep for parents in the first year

- One of the best predictors of insomnia later in life is the development of bad habits from having sleep disturbed by young children.

- REM sleep occurs in bursts totalling about 2 hours a night, usually beginning about 90 minutes after falling asleep.

- No-one knows for sure if other species dream but some do have sleep cycles similar to humans.

- Scientists have not been able to explain a 1998 study showing a bright light shone on the backs of human knees can reset the brain's sleep-wake clock. Wha?

- Seventeen hours of sustained wakefulness leads to a decrease in performance equivalent to a blood alcohol-level of 0.05%.

- The 1989 Exxon Valdez oil spill off Alaska, the Challenger space shuttle disaster and the Chernobyl nuclear accident have all been attributed to human errors in which sleep-deprivation played a role.

- The NRMA estimates fatigue is involved in one in 6 fatal road accidents.

- Exposure to noise at night can suppress immune function even if the sleeper doesn’t wake. Unfamiliar noise, and noise during the first and last two hours of sleep, has the greatest disruptive effect on the sleep cycle.

- The "natural alarm clock" which enables some people to wake up more or less when they want to is caused by a burst of the stress hormone adrenocorticotropin. Researchers say this reflects an unconscious anticipation of the stress of waking up.

- Tiny luminous rays from a digital alarm clock can be enough to disrupt the sleep cycle even if you do not fully wake. The light turns off a "neural switch" in the brain, causing levels of a key sleep chemical to decline within minutes.

- To drop off we must cool off; body temperature and the brain's sleep-wake cycle are closely linked. That's why hot summer nights can cause a restless sleep. The blood flow mechanism that transfers core body heat to the skin works best between 18 and 30 degrees. But later in life, the comfort zone shrinks to between 23 and 25 degrees - one reason why older people have more sleep disorders.

- A night on the booze will help you get to sleep but it will be a light slumber and you won't dream much.

- After five nights of partial sleep deprivation, three drinks will have the same effect on your body as six would when you've slept enough. Cheap date!!!

- Humans sleep on average around three hours less than other primates like chimps, rhesus monkeys, squirrel monkeys and baboons, all of whom sleep for 10 hours.

- Ten per cent of snorers have sleep apnoea, a disorder which causes sufferers to stop breathing up to 300 times a night and significantly increases the risk of suffering a heart attack or stroke. Hmmmmm...

- Snoring occurs only in non-REM sleep

- Teenagers need as much sleep as small children (about 10 hrs) while those over 65 need the least of all (about six hours). For the average adult aged 25-55, eight hours is considered optimal

- Some studies suggest women need up to an hour's extra sleep a night compared to men, and not getting it may be one reason women are much more susceptible to depression than men. Mood swings...just sayin'.

- Feeling tired can feel normal after a short time. Those deliberately deprived of sleep for research initially noticed greatly the effects on their alertness, mood and physical performance, but the awareness dropped off after the first few days.

- Experts say one of the most alluring sleep distractions is the 24-hour accessibility of the internet.

- The extra-hour of sleep received when clocks are put back at the start of daylight has been found to coincide with a fall in the number of road accidents.