SLEEPING

Sleep stages:• Stage 1- Hallucinations• Stage 2- Sleep spindles• Stage 3- Transitional sleep• Stage 4- Deep sleep

SLEEP CYCLE

There is a five stage cycle• Repeats every 90 minutes

REM sleep

REM increases as night progresses

SLEEP NEEDS AND DEPRIVATION

Sleep needs in age groups:• Newborns will sleep 6 to 8 times in a 24 hour period

(more than 16 hours per day• 6 year old child needs up to 11 or 12 hours of sleep

per night• As the child grows up they need less and less sleep

until they are an adult only needing 7-7.5 hours of sleep per night (they may need even less as they get older.

• During a whole lifetime we need about 1 hour of sleep to every 2 hours we are awake.

SLEEP AND MEMORY

When learning a difficult perceptual task and are kept up all

night after finishing practicing the task, the learning is wiped

out

Sleep after learning is essential for memory consolidation

The memory normally deteriorates unless sleep occurs.

**Pulling an all nighter to study for an exam is not the best

option because the information being learned will not stick in

your memory*** EXTREME SLEEP LOSS CAN BE FATAL!!

SLEEP DEPRIVATION

Sleep deprivation can have a detrimental effect

even on the healthiest of young people; it can cause

an increase in irritability, reduce acuity and reaction

time, and increase depression. People who do not get

enough sleep are also more prone to accident and

injury.

REM SLEEP AND ITS IMPORTANCE

Memory problems and excessive aggression are

observed in both humans and rats when awakened

whenever the REM activity starts.

SLEEP DISORDERS

Medication: People use sleep medication to help

with Insomnia but this is not always a benefit• Most sleeping pills are addictive • Sedatives can interfere with the normal sleep cycle• Reduce the proportions of time spent in REM and

slow-wave sleep• Grogginess and irritability during the day• Stopping the treatment to abruptly can cause

insomnia worse than before.

DISORDERS

Insomnia: Difficulty in falling asleep or staying

asleep• About 15% of adults suffer from severe insomnia• About 15% of adults suffer from a mild case of

insomnia • Causes for insomnia include anxiety associated with

stressful life events.

Sleep Paralysis: The experience of waking up

unable to move• Associated with narcolepsy• Only lasts a few moments and can cause pressure on

the chest

DISORDERS CONT.

Sleep Apnea: Disorder in which the person stops

breathing for brief periods while asleep.• Occurs most often in middle-aged, overweight men • Snoring and noisy gasping for air are some signs of

sleep apnea • Usually this disorder goes undiagnosed because it is

easy for the sleeper to not notice.• Sleep may seek treatment because of excessive

sleepiness during the day.• Some treatment include weight loss, drugs, or

external breathing aids

DISORDERS CONT.Somnambulism (Sleepwalking): Person arises and walks

around while asleep. Common in children around the age

of 11 or 12 • 25% of children experience at least one episode• Sleepwalking happens early in the night usually during

slow-wave sleep, and sleepwalkers may awaken during their walk or return to their bed without waking.

• Sleepwalker will usually not remember the sleep walk the following morning

• The eyes of the sleepwalker are usually open and glossed over when walking occurs.

• The only problem is the physical harm that can come to the sleepwalker by tripping over objects or falling down stairs.

• It is safe to wake a sleepwalker or lead them back to their bed if necessary.

THE LAST OF DISORDERS

Narcolepsy: A disorder in which sudden sleep attacks

occur in the middle of waking activities.• Attacks can last from 30 seconds to 30 minutes depending on

the individual • Is hereditary and runs in families and can be treated

effectively by medication

Night terrors (Sleep terrors): Abrupt awakenings with

panic and intense emotional arousal. Usually occurs in boys

ages 3-7• Occur during NREM or at the beginning of sleep cycle and

dreams are not associated with night terrors

DREAMING

“Dreaming permits each and every

one of us to be quietly and safely insane

every night of our lives.”-William C.

Dement (1959)https://www.youtube.com/watch?v=z2BgjH_CtIA

5 MAJOR CHARACTERISTICS

1. We feel emotion

2. Dream thought is illogical

3. Sensation is formed and is meaningful

4. Dreaming occurs with uncritical acceptance

5. Difficulty remembering the dream after it is over

DREAM THEORIES

Sigmund Freud• Dreams are confusing and obscure. Dynamic

unconscious creates them to be confusing and obscure.

• They represent wishes and some are unacceptable, taboo and anxiety producing

-Problem: infinite number of interpretations of any dream-BUT evidence that dreams do feature the return of suppressed thoughts.

DREAM THEORIES CONT.

Hobson and McCarley 1977• Activation-synthesis model: dreams are produced

when the mind attempts to make sense of random neural activity that occurs in the brain during sleep.

• In the dream state mind does not have access to external sensations. The information is from neural activations without perception of reality.

• The interpretive mechanisms of the brain can run free!

DREAMING BRAIN

Different brain areas show activation during REM

sleep.

Brain area responsible for fear or emotion work

overtime in dreams. For example the amygdala

(responses of stressed or threatening events) is quite

active during REM

Areas responsible for visual perception are NOT

activated, but visual association in the occipital lobe

is activated

THE BRAIN CONT.

During REM sleep:• Prefrontal cortex shows less activity• The eyes move rapidly but the body is very still, so

motor cortex activated but spinal neurons inhibit expression of motor activation

TEST QUESTION

What is one of the 5 signs of REM sleep?• Possible answers: 1. pulse quickens

• 2. blood pressure rises• 3. old tale of sexual arousal• 4. very little muscle movement, the sleeper is very still• 5. rapid side-to-side eye movement