SLEEP

SLEEP AND DREAMS

One third of our lives spentdoing it!(SLEEP)

What is SleepA state of

(1) sustained immobility (2) characteristic posture accompanied by (3) reduced responsivity to external stimuli

Why are some reasons we need sleep?

Sleep allows our body to rest and repair itself!Sleep: Allows us to rest

Gives us energy

Improves mood

Makes us alert

Helps with memory

Sleep appears to be anessential physiological processfor humans and for most other animals, other than very simple ones with small brains. When deprived ofsleep, we function less effectively, feel tired and irritable, make more mistakes, are less creative and, if taken to extremes, ultimately die. In the same way as a feeling of hunger reminds us of thebasic human needto eat, a feeling of sleepiness reminds us of our essential need tosleep.

Sleep NeedSleep need is the amount of sleep we need to stay alert during the day. How many hours do teenagers need to sleep each night? 8 10 Hours!

Sleep debtSleep debt is when we get less sleep than we need.

We need: We get: Sleep debt:

What does sleep debt affect?AlertnessLearning and memoryMoodEnergyControl and coordination

Sleeping is an active process

Some parts of our body slow down:Breathing Heart rateDigestion

Other parts speed up: Our BRAIN

Brain activity is measured as electric waves

BRAIN WAVESYour brain is made up of billions of brain cells called neurons, which use electricity to communicate with each other. The combination of millions of neurons sending signals at once produces an enormous amount of electrical activity in the brain, which can be detected using sensitive medical equipment (such as an EEG), measuring electricity levels over areas of the scalp. The combination of electrical activity of the brain is commonly called a Brainwave pattern, because of its cyclic,'wave-like'nature.Our mind regulates its activities by means of electric waves which are registered in the brain, emitting tiny electrochemical impulses of varied frequencies, which can be registered by an electroencephalogram

1Betaemitted when we are consciously alert, or we feel agitated, tense, afraid, with frequencies ranging from 13 to 60 pulses per second in the Hertz scale.

2Alphawhen we are in a state of physical and mental relaxation, although aware of what is happening around us, its frequency are around 8 to 13 pulses per second.

3Thetamore or less 4 to 7 pulses, it is a state of somnolence with reduced consciousness.

4Deltawhen there is unconsciousness, deep sleep or catalepsy, emitting between 0.5 and 4 pulses per second.

Different types of brain waves exist during our sleep cycle

There are two types of sleep: REM and Non-REMREM: Rapid eye movement Dreaming occurs during REM sleep. NREM: Non-REM sleepTheAmerican Academy of Sleep Medicine(AASM) divides NREM into three stages: N1, N2, and N3, the last of which is also called delta sleep or slow-wave sleep.

Stage 1NREM stage 1: This is a stage between sleep and wakefulness. The muscles are active, and the eyes roll slowly, opening and closing moderately.transition of the brain fromalpha waveshaving afrequency of 813Hz(common in the awake state) totheta waveshaving a frequency of 47Hz.drowsy sleep

STAGE 2NREM stage 2: theta activityis observed sleepers become gradually harder to awaken muscular activity decreases, and conscious awareness of the external environment disappears. This stage occupies 4555% of total sleep in adults.

STAGE 3NREM stage 3: Formerly divided into stages 3 and 4, this stage is calledslow-wave sleep(SWS). The sleeper is less responsive to the environment; many environmental stimuli no longer produce any reactions.Delta waves are activated

REM SLEEP

where most muscles are paralyzed.

REM sleep is turned on. This level is also referred to asparadoxical sleepbecause the sleeper, although exhibiting EEG waves similar to a waking state, is harder to arouse than at any other sleep stage.

REM SLEEP Oxygen consumption by the brain is higher than when the sleeper is awake.An adult reaches REM approximately every 90 minutes.Most memorable dreaming occurs in this stage.Heart rate and breathing rate are irregular during REM sleepBody temperature is not well regulated during REM sleep

DreamsDream is a word used to describe the subconscious experience of a sequence of images, sounds, ideas, emotions, or other sensations usually during sleep, especially REM sleep

There is no neurologically agreed upon, biological definition for dreaming

Dreaming is stimulated by thepons

But there is a lot that is unknown about dreams and the purpose of dreams is interpreted in many different ways

Sigmund Freudpostulated that dreams are the symbolic expression of frustrated desires that have been relegated to theunconscious mind,

Activation Synthesis theoryCertain processes in the cerebral cortex have been studied byJohn Allan HobsonandRobert McCarley. In theiractivation synthesis theory, they propose that dreams are caused by therandomfiring ofneuronsin thecerebral cortex during the REM period.

Lucid DreamingLucid dreaming occurs when dreamers realize that they are dreaming (lucid dreaming can occur with varying levels of awareness and dream control)The dreamers are sometimes capable of changing their dream environment and controlling various aspects of their dream.

What is the purpose of dreams?Freud proposed that dreams protect sleep, which might be disturbed by the arousal of unacceptable wishesFerenczi proposed that dreams may communicate something that is not being said outright (subconscious thoughts)Another idea is that dreams helps the mind run tests of its Emergency Broadcast System, a way to prepare for potential disaster. For example, when new mothers dream about losing their babies, they may actually be rehearsing what they would do or how they would react if their worst fears were realized.

FACTSHumans spend about 6 years dreamingDreams are generated in the forebrainMost common emotion experienced during dreaming is anxietyTwelve percent of people dream only in black and white

Simple habits for improving sleepOnly go to bed when you aresleepy. Ifsleepdoes not come reasonably quickly - within, say, 20-30 minutes or even less - get up and try again later (try to avoid bright lights while you are up, though).Do notoversleep, as it may leave you feeling unrefresh and sluggish the next day, as well as confuse your internalbiological clockfor subsequent nights.Use your bed only forsleep not for television viewing, telephone calls, work, etc. Try to establish a strongmental associationbetween the bedroom and sleeping.If possible, try to keep yoursleepand waking timesregular, even on weekends, in an effort to train your biological clock. Makesleepa priority, even when time is short.

Do not engage instrenuous exercise,heavy mealsor ahot bathjust before going to bed: all of these activities work to increase body temperature which will make it harder to fall asleep. A lukewarm bath or shower, however, can help relax your muscles and make falling asleep easier.A littlemoderate exercise, such as an evening stroll, can help yousleep, and more strenuous exercise earlier in the afternoon is also beneficial. But avoid intense exercise too close to bedtime (within 3-4 hours).Make sure yourevening mealis not too light and not too heavy, and a good two or three hours before bedtime. High protein foods might keep you awake at night, and may be better options for lunchtime. Foods containingtryptophan(e.g. bananas, dates, nut butters, tuna, turkey, yoghurt, milk) and carbohydrates like bread or cereal, on the other hand, may help encourage drowsiness andsleep. As with everything else, abalanced dietwith plenty of fresh fruits, vegetables and whole grains will help in the long term.

Avoidcaffeinated drinkslike coffee, tea, cola, energy drinks, etc, near bedtime (certainly within 3-5 hours, and preferably much longer than that), and try not to drink too much of anything too late in the day, in order to avoidbathroom trips. A hot milk or herbal tea before bed, however, may help encouragesleep.Avoid otherstimulants, such asalcoholortobacco, before going to bed. Alcohol may help you get tosleep in the first place, but it will disturb yoursleeplater, preventing you from entering the deeper restorative stages of sleep, and causing you to wake frequently during the night.Relaxingbedtime habitsor rituals, such as reading or writing, just before bed can help to relax you and take your mind off any anxieties you might have about sleeping. Bedtime rituals are particularly important for children, especially when they reach the stage, as most do at some point, of resisting bedtime and encountering difficulties falling asleep.

Similarly,meditation, relaxation exercises, soothing music or just a period of calmdeep breathingbeforesleepcan all help to calm you down and alleviate stress and anxiety.Sleepon a goodcomfortable mattresswhich helps you maintain a goodsleepposture, and acomfortable pillowthat allows for efficient unobstructed breathing and a good neck and spine position duringsleep(for more details, see the section onSleeping Positions).Avoid exposure tobright light(especially blue light) close to bedtime, as it may confusecircadian rhythms and triggerawakeningrather than sleeping processes. Try to get regular exposure tooutdoor lightduring the day (in particular, direct sunlight straight after waking can help establish goodcircadian rhythms).

Ensure that the bedroom isnot too hotortoo cold. Old-fashioned remedies like wearingbed-sockscan really help in cold weather, as they slow heat loss to the extremities and so make it easier to fall asleep.Ensure that the bedroom isfully dark(use blackout blinds is necessary), and that it is isolated, as far as possible, fromintrusive noises(use earplugs or white noise machines if necessary).Use thebathroombeforesleepin order to avoid unnecessary trips to bathroom during the night. If you do have to use the bathroom at night, use the minimum possible amount of light to navigate.If you are having problems sleeping at night, avoidnapsduring the daytime, as they tend to borrow from the next nightssleep, unless they are very short (10-20 minutes).

If you are not sleeping well, avoidwatching the clockand do not put mental pressure on yourself or get upset about the situation - you cannot force yourself tosleep, and this can only be counterproductive.Write down anytroubling thoughtsbefore bed-time, so that they wont dwell on them through the night.Sedatives should be taken only as alast resort, but they may help to establish asleephabit if taken as a temporary short-term solution.