Sleep

consciousness

Awarness of your own thoughts, feelings, sensations and perceptions

Consciousness continuum

The more aware we are of our thoughts, feelings, perceptions and surroundings, the higher the level of consiousness.

Normal walking consiousness

Awake and aware of our internal and external environment.

-experience a clear sense of time and place

-can manage our attention, behaviour

-thoughts and perpceitons are organised and clear

Altered state of consciousness

State of consiousness that is distinctly different to NWC, can be naturally occuring (sleep) or induced (medication, intoxication) in terms of quality of expeirnece and level of awarness

Characteristics of Altered state of consiosuness

-Lack of control over thoughts

-Lack of emotional awarneess

-Lack of time orientation

-Reudced responsiveness to itnernal and external stimulu

Sleep

Regular and naturally occuring altered state of consiosuness that invovles a loss of awarness and disengagement with internal and external stimuli

REM sleep

Rapid eye movement, hgih levels of brain activiity and low levels of physical acitviity.

Simialr brain waves to when we are awake (beta-like)

Non-rapid eye movemnt (NREM)

type of sleep characterised by lack of rapid eye movement

Compare NREM and REM sleep

Faster eye movemnt in rem than NREM

Brainwaves in REm are beta and brainwaves in NREM are delta

NREM stage 1

-Light sleep

-Hypnagogic state (experience floating/falling or sudden jerk-hypnic jerk)

Loses awareness of themselves and their surroundings but is still aware of faint sounds in the envrionment

-Physiological responses begin to slow down-brain acitivity, body temp, heart rate etc

-Most easily woken

-Hypnic jerks (reflex muscle contractions) occur

-Lasts 2-10 mins

NREM stage 2

considered to first be asleep lasts 20-30 mins.

Light sleep

Physiological responses continue to slow down

-Bursts of brain acitviity help reist being woken up by environmental stimuli such as noises

-Theta waves dominate with occasional spikes and patterns such as sleep spindles and k-complex

Sleep spindles

Short brusts of high frequnecy brain activity may indictae when sleep begins

K-COmplex

Single large burst of high amplitidue brain acitivty (associated with memory consolidation)

NREM stage 3

Slow wave sleep due to brain activity being at its slowest

Physiological responses are at their slowest

Most difficult to wake up

Delta waves dominate (high amp, low frequency)

- if woken may be disoriented and drowsy

Sleep walking, sleep talking most lieklt to occur

-Occurs about an hour after falling asleep and lasts 20-40 mins

Measuring consiocusness (physioloigcal)

Hr, Body temp, galvanic skin response, eye movement, muscle movement brainwaves

Measuring consiousness (psychological indicators)

Content limiations

Perceptual and congitive distortions

Emotional awarness

self control

time orientation

Electroencephalograph (EEG)=Brain waves

Detects, amplfiies, records the elctrical acitivty of the brain.

High frequency and low amp for NWC

-Decrease in higher frequency and increase in lower frequnecy for ASC

Electromyograph (EMG)=muscle tension

Detects, amplfiies and records the electrical acitviity of the skeltal muscles

-The more muscle tension-the more alert

Lower levels of movement-ASC-none in REM sleep

Higher levels of movvmeent-awake/light sleep

Electro-oculograph=eye movements

Device that detects, amplfies and records the electrical activitiy of the muscles responsible for eye movement

Determine if in NREM or REM

Measuring pscyholoigcla responses

Video monitoring and sleep diaries (self-reports)

Self reports (sleep diaries) adv, disadv

More detailed info (like a case study)

Can collect both quantitiative and qualitiative data

Placebo effect/demand characteristics

Subjective bias-prone to personal itnerpretaition

Polysomnography

Study of sleep that uses devices to collect objective data often in sleep labs

Electrocardiograph (ECG) (DARE)

detects, amplifies and records electrical activity of the heart

Sleep lab adadv, disadv

Quantitiative, objective, numerical data

Controlled expeirmnt

Artificiality-behaviour may be affected by the unnatural environemnt

Biological rhythms

Natural cycles that our bodies follow to perform regular functions

Circadian rhyms

biological processes that co-ordinate the timing of body acitivities over a 24-hour peiord.. control our sleep-wake cycle, release of hormones and regulation of body temp

Sleep wake cycle

A type of circadian rhym, a 24-hour cycle that is made up of time spent sleeping and time spent awake and alert

Ultraradian rhyms

Repeated biolocial cycles that occur less than every 24 hours.

HR, eye blinks, sleep stages, digestion

Internal bioloical clock (circadian rhym)

Found in our hypothalamus, located in the midbrain, called the Suprachiasmatic nucleus (SCN)

How is melatonin released

light is detected by the eye

-This stimulates the suprachiasmatic nucleus (SCN) in the hypothalamus

-The SCN signals the pineal gland to release melatonin

Suprachiasmatic nucleus (SCN)

Structure in the hypothalamus that regulates an indiivudals sleep-wake patterns, activated by zeitgebers

Zeigebers

external cues such as light, temp, noise, food etc which elicit bioloical cyclical changes. Main zeitgeber responsible for regulating our sleep wake-cycle is light which activate the SCN

Infancy/childhood

Born-Sleep approx 16 hours daily (50% REM)

By age 2-12-13 hours daily (25-30% REM)

Childhood-10 hours (20-25% REM)

Adolesence

Teenagers-9 hours sleep

-Bed later and difficulty waking in mornings

-Loss of sleep results in tiredness, lack of motivation, irritability, poor academic perfomance etc

Adolescent sleep-wake cycle shift

Body clock shifts forward and pushes onset of sleep back later in the night

Bioloical factors-ppuberty causes melatonin to be released 1-2 hours later

Environmental factors-staying up later to socialise, finish homeowrk etc

Total sleep deprivation

No sleep for a 24 hour peirod

Partial sleep deprivation effects on AFFEctive funcitoning

Decreased positive mood and increased negative mood which makes us more vulnerable to stress, anxiety and depression

Partial sleep deprivation effects on congitive funcitoning

Poor concentration-difficulty maintaining focus and attention. Poor problem solving and decision making.

Imapcts automatic processes more than controlled processes (simple, routine, automatic tasks than complex ones)

Partial sleep deprivation effects on behavioural functioning

poor co-ordination, fine motor skills, slower refelxes and reaction times, difficulties completing routine tasks

Circadian rhythm sleep disorders

Disturbances to typical sleeping and waking patterns that interefere with the regulation of the circadian rhythm of sleep

Zeitgebers

External cues from the environment that influence the circadian rhythm. Light, temperature, eating and drinking patterns, exercise, socialisation

Biological basis of sleep (night time)

Zeitgeber (darkness)

SCN (body-clock)

Pineal gland releases melatonin

Adrenal gland stops producing cortisol

Makes us tired to fall asleep

Biological basis of sleep (day time)

Zeitgeber (light)

SCN (body-clock)

Pineal gland stops producing melatonin

Adrenal gland releases cortisol

Become aroused to wake up

Good sleep hygeine

Nightly ritual

Same bedtime and wakeup time

Regular exercise (4 hours before bed)

Light cues-reduce levels of light 2 hours before bedy

Exposure to natural light-decrease melatonin and increase cortisol

Blue light

Emitted by the sun, and by artificial light sources and has greatest ability to inhibit the release of melatonin

Temperature

Hypothalamus including the SCN regulates homestasis and body temp to warm us up for the day and cool us for sleep. 19-21 is optimal

Eating and drinking patterns

Foods release enegry that arouses you and digestion is more efficient earlier in the day

Purpose of sleep (restoration theory)

Suggests we need to sleep to recover and revitalsie our body and mind so we can funciton properly when awake.

replensihes energy reserves, repairs cell damage, detoxifies our system of waste products.

NREM restores….

The body-repairs muscle and tissue damage and relieves physical activitiy

REM restores….

the brain-mental processes and allows the brain to regenrate and refocus

Sleep

Pscyhological consturct that is a naturally occuring altered state of consisouness that is categoried into REM and NREM sleep.

REM sleep

characterised by quick darting of the eyes and an increase in physiologicla activity

Brain activiity resembles wakefulness-HR and RR increase

-Voluntary muscles are virtually paralayzed

-Can be woken fairly esily

-20-25% of a sleep episode

-brain is repairing

Hypnogram

Stages of sleep on y-axis

Wakefulness at the top and deepest sleep at the bottom

duration on x axis

amplitude

indicates the intensity of the brain wave-how many neurons are firing at the same time

Frequnecy

How fast they occur per second

Sleep diaries

Subjective, self-report tool to track your own sleep and wake patterns.

Written and verbal insutrctions

Melatonin

Involved in the intiation of sleep and regulation of the sleep-wake cycle. Pineal gland releases melatonin into the bloodstream.

High levels of light

detected by the eyes, eyes send a message to the SCN, SCN sends an inhibitory message to the pineal gland, pineal gland stops secretion of melatonin

-Promotes wakefulness

Low levels of light

Detected by the eyes, eyes send message to the SCN, SCN sends an excitaory message to the pineal gland, pineal gland releases melatonin, promotes drowsiness

Babies (0-2)

50% REM, need more due to rapid growth and development

Circadian rhythm starts to develop around 5 months old

Childhood-3-12

9-11 hours

20% REM

Circadian rhythm advances and sleep onset starts earlier in the evening (6-7)

Adolescents- 13-18

8-10 hours recommended sleep

• 20% REM 80% NREM

• Circadian rhthm delays (and melatonin release is therefore delayed) so adolescent may not feel tired until later in the evening (towards midnight)

Adult 19-64

Adults- 19-64

• 7-9 hours recommended sleep

• 20% REM 80% NREM

• Life factors such as work or study commitments, social events, parenting young children can contribute to challenges getting adequate quality and quantity of sleep

  • Circadian rhythm advances after adolescent to sleep onset around 9-10pm

Older adults-65+

6-8 hours recommended sleep, less rem

• lighter sleep, more akwaenings

• Stage 3 (Deep slow wave sleep) is rarely expeirenced

• 18-20% REM

  • Circadian rhythms advances and can lead to earlier sleep onset and awakening (can be earlyy)

Parital sleep deprivation

Experience of ahcieving inadequate sleep in terms of quality or quanity over a 24-hour period

Sleep quantity

How well you sleep (ie. if you woke up during the night or how deep or restful is)

affective functioning

refers to a persons experiences of their emotions.

Mood changes, heightened anxiety, depression, irritability, lack of motivation,

Behavioural funcitoning

Persons observable actions.

Slower reaction times, clumsiness, risk-taking behaviours

Cognitive fucnitoning

refers to a persons mental processing.

Lack of cocnentration, impaired memory, irrational thoughts, poor decision making

Physiological effects of sleep deprivation

Fatigue, trembling hands, drooping eyelids, slurred speech, lack of energy, headaches

Similaritieis between sleep deprivation and BAC

17 hours of being awake is equivalent to the effects of a BAC of 0.05%

Effects of 24 hours of person being awake are equalivent to the effects of a BAC of 0.1%

Circadian rhythm sleep disorders

your internal sleep wake cycle is not aligned with their external day night cycle, impacting sleep quantity and quality: caused by intrinsic/biological facotrsd (age, stress, medical conditions or external

Delayed sleep phase syndorme (adolescent sleep-wake cycle shift

circaidan rhytm sleep disroder characterised by falling asleep later and waking up earlier due to melatonin being released later.

delay for 2 or more hours

Disorder when it lasts over 3 months

Advanced sleep phase disorder

Elderly people-Go to sleep earlier and waking up earlier-affects quality and quantity of sleep and how well u function during the day

2 hours earlier than what is needed to acceptable

Effects of circadian rhythm sleep disroders

May experience amplfiied emotional response, faitgue, irritability, reudced ability to concentrate

Shift work

paid employment to be alert and awake at night time and sleep at day time.

Can result in distress and dysfucntion poor mental wellbeing.

Operate in contradiction to your hormones, melatonin is increased to make you tired and cortisol has dropped to make you less aroused but you have to be alert and awake.   You are asked to go to sleep during the day when your melatonin levels decrease to make you more alert and cortisol increases.

Bright light therapy

Therapy to treat a sleep disroder where the person is exposed to a high intensity light source to reset the sleep-wake cycle.

Delays release of melatonin

Bright light therapy for delayed sleep phase syndrome

Exposed to bright light source in the morning. Act as an external cue to the SCN and promote wakefulness.

Pull clock forward to reset circadian rhythm to secrete melatonin earlier in the night to fall asleep earlier.

Bright light therapy for advanced sleep phase disordrer

Exposed to the bright light soruce in the evening. Act as an external cue to the SCN to promote wakefulness and send signals to release melatonin later thus promoting sleep.

Push body clock backwards.

Bright light therapy for shift work related sleep disroder

exposed before beginning their work to promote wakefulness when they need to be awake and alert. promote sleepiness at a later, more suitable time

Sleep hygeine

Sleep related behaviours and environmental conditons that are benefical for sleep.

No screens, caffeine, follow bedtime routine, ensure cool temp, avoid hard exercise 4-5 hours before bed

Good sleep hygeine results in

Fall asleep quicker, remain asleep and better sleep quality and quanitity

Zeitgebers-light

Light signals to the SCN to supresses melatonin, promoting wakefulness.

Blue light can inhibit melatonin secretion

Reduce screen brightness settings, don’t use screens

Zeitgebers adaption

Expose yourself to daylight in the morning and early afternoon.

Sleep in as much darkness as possible

Hour before bed-minimsie blue light

Zeitgeber-Temperature

Body temp decreases in the early evening. ideal room temp for sleeping is 19-21 degrees.

Cool room and warm bedding promotes sleep

Zeitgebers-eating and drinking patterns

Don’t eat too late and avoid caffeinated or sugary foods near the end of the day

Partial sleep deprivation defintion

refers to expeirnece of ahevingin inadeuqate sleep in terms of quality or quanity iver a 24-hour period

Microsleep

a short period of loss of consciousness that can occur as a result of sleep deprivation while a person is apparently awake (less than 30 seconds).

Predisposing risk facotrs for DSPS

Increased sensitivity to light-Delayed signal to the SCN which delays melatonin relelase

Longer than average circadian period

Sleep hygeine

Reduce light, daylight in the morning,

Body temp for sleep hygeine

Zeitgeber, on a 24-hour circiadian rhythm-decreases towards bedtime, supported by 19-21 degree bedroom.

Eating and dirnking patterns-sleep hygiene

Don’t eat a big meal 3-4 hours,