Psychology U4 AOS 1

A) Consciousness

B) Is it a psychological construct. Why/why not?

Consciousness is the level of awareness an individual has over their own internal and mental processes including their thoughts, feelings, perceptions and existence, and awareness of the external world around them 

• It is a psychological construct meaning that it is a concept that cannot be objectively observed or measured through the collection of data but is widely understood to exist 

• Normal waking consciousness (NWC)

• Altered state of consciousness (ASC) + examples

• In ASC, level of awareness is only lower than in NWC. T or F?

• Normal waking consciousness (NWC) is a state of consciousness in which an individual is awake and aware of their internal and external environments 

  • In this state, individuals can manage their attention and thoughts and perceptions are organised, logical and clear 

 

• Altered state of consciousness (ASC) is a state of consciousness that is distinctly different/differs from normal waking consciousness (in terms of quality of experience and levels of awareness) 

e.g. 

• Coma 

• Under anaesthetic 

• Drug induced state 

• Intoxication 

• Meditation 

• Hypnosis 

• Sleep 

• False. In this state, level of awareness is lower or higher in NWC.

Altered states of consciousness can be further categorised into induced or naturally occurring.

Explain what these mean and give examples of which ASC is what:

consciousness continuum

The consciousness continuum is a visual representation of the different states of consciousness that progress from lower levels of awareness to higher levels of awareness 

• Sleep + is it a psychological construct

• Characteristics

Sleep is a regular and naturally occurring altered state of consciousness that involves a loss of awareness of the world and disengagement with internal and external stimuli 

• It can also be considered a psychological construct 

 

Characteristics of sleep include:  

• a reduced ability to control behaviour  

• a reduction in the control we have over thoughts, for example, we lack control over what we dream about  

• less accurate understanding of the passage of time  

• perceptual and cognitive distortions 

What are the two types of sleep? Explain each.

• REM (rapid eye movement) sleep is a type of sleep characterised by rapid eye movement, high levels of brain activity, and low levels of physical activity 

 

• NREM (non-rapid eye movement) sleep is a type of sleep characterised by a lack of rapid eye movement and is subdivided into three different stages 

--> It's divided into 3 stages of sleep 

• Sleep episode

• Sleep cycle + how long are they typically

• How many sleep cycles in each episode

• A sleep episode is the full duration of time spent asleep which is made up of multiple repeated cycles of REM and NREM sleep, called sleep cycles --> each sleep cycle is an approximately 90-minute-period that repeats during a sleep episode  

--> The number of sleep cycles an individual experiences in a sleep episode depends on an individual’s sleep duration (However, on average, there are usually around five or six sleep cycles during a typical sleep episode) 

Compare REM and NREM sleep:

(Hint: brain activity, muscle movement and tone, type of sleep, ability of person to wake up, dreaming, proportion of sleep episode it takes up, heartrate/breathing rate, other names)

REM	NREM
Heart rate, breathing and metabolic rate all increase  Brain is active – emitting high frequency and low amplitude brainwaves	Neural activity slows down   Heart rate, breathing rate and metabolic rate all decrease
Experienced muscle paralysis (muscle atonia) - muscle tone and movement is at its lowest
Also called paradoxical sleep – due to active internal functions occurring at the same time as body's limbs experience muscle paralysis
More vivid dreaming, structured, intense and frequent dreaming  - dreaming for about 80% of the time

Compare different stages of NREM sleep:

(Hint: types of sleep, movement, length, proportion of sleep episode, waking ability, other names and more)

NREM stage 1	NREM stage 2	NREM stage 3
When moving into stage 1 of NREM sleep, the sleeper transitions from being awake into a light sleep   --> this transition is signified by the experience of the hypnagogic state, in which some people experience feelings of floating or falling or a sudden jerk (known as a hypnic jerk)    In this stage, the sleeper loses awareness of themselves and their surroundings but is still aware of faint sounds in the environment    The sleeper can be easily woken in stage 1 – very brief & light sleep    If woken, people are likely to report that they were not asleep at all    Lasts around a couple of minutes (maybe 10)	In this stage, , the sleeper is still in a relatively light sleep    Individuals spend the majority of their time asleep in NREM stage 2 (almost half)     In this stage, the sleeper is considered ‘truly’ asleep, due to the types of brain waves occurring    People are rather easy to wake     Muscles & body are relaxed and show little to no movement    Lasts around 10-25 minutes – lengthens with each consecutive cycle	Also called slow wave sleep – as brain activity being at its slowest    The sleeper is in a deep stage of sleep --> it is difficult to wake the sleeper in this stage of NREM     If the sleeper is woken during this stage they are likely to feel drowsy and disoriented    During this stage, sleepwalking and sleep talking are most likely to occur    Heart rate, breathing and brain activity are at their lowest    Muscles are very relaxed    Experienced more in the first half (and less in the second half)

When we fall asleep, we experience (in order) in a cycle – 90 min:  —> in reference to the different types of sleep

• NREM 1 sleep 

• NREM 2 sleep 

• NREM 3 sleep 

• NREM 2 sleep 

• REM sleep 

What is this called and what is it used for?

Above is a hypnogram, which is a sleep graph that tracks the proportion of time spent in each stage of sleep, including awakenings, throughout a sleep episode 

• Polysomnography

• Some measures of consciousness (and consequently sleep) include:  

• How do these measures differ

Polysomnography: sleep study consisting of various methods of data collection 

 

Some measures of consciousness (and consequently sleep) include:  

• the electroencephalograph (EEG)  

• the electromyograph (EMG)  

• the electro-oculograph (EOG)  

• sleep diaries  

• video monitoring 

 

• EEGs, EMGs, and EOGs are considered to be objective physiological measures in which they provide reliable, unbiased, quantitative data that can indicate someone’s state of consciousness 

• However, they do not provide qualitative detail about the personal experience of sleep, such as an individual’s thoughts or feelings. 

• Additionally, changes in physiological responses may be due to factors other than a change in consciousness, thus the findings may lack validity at times 

 

• Sleep diaries and video monitoring are considered to be subjective measures – meaning that information is provided by an individual and is related to their personal experiences --> the accuracy and reliability of such measures can be limited due to their subjective nature 

• Subjective data includes both qualitative and quantitative data 

• Electroencephalography (EEG) 

• How is this measured/used

An electroencephalograph (EEG) is a device that detects, amplifies, and records the electrical activity of the brain's neurons 

• When neurons communicate, they emit electrical impulses which are detected by the EEG and then presented as brain wave patterns --> which are then used make a judgement about the state of consciousness a person might be in 

• In order to take these readings, a medical professional/researcher attaches electrodes to the outside of a person’s head – on a person's scalp or through a cap that is worn 

Do EEGs measure brain waves in the brain?

No.

It is important to understand that EEGs measure electrical impulses that are then represented through brain waves

• In this way, EEGs do not actually measure brain waves, but rather brain waves are used to describe the electrical activity of the brain.

• Hence, you should say that EEG recordings show specific brain waves to represent the electrical activity of the brain, rather than that the brain shows specific brain waves

• Brain waves vary in frequency (rate) and amplitude (height): What do these mean?

• Describe the type of brain waves displayed when a person is active vs has lower levels of alertness?

• Frequency is the number of brain waves that occur per second 

• Amplitude is the intensity and height of the brain waves 

Describe the type of brainwaves shown in the different stages of sleep (REM, N1, N2, N3)

• Higher frequency and lower amplitude in REM sleep - due to brain being active in REM sleep 

• High frequency and low amplitude in NREM sleep stage 1 (transitioning from wakefulness to sleep), but lower frequency and higher amplitude than normal-waking consciousness 

• Medium frequency and medium amplitude in NREM sleep stage 2 (light sleep)  

• Lower frequency and higher amplitude in NREM sleep stage 3 (deep sleep) 

• Electromyography (EMG) 

• How is this measured/used

An electromyograph (EMG) is a device that detects, amplifies, and records the electrical activity of the body’s skeletal muscles 

• This is done by attaching electrodes to the skin above the muscles under investigation, the movement and tension of muscles are recorded 

 

TIP: To remember what EMG measures --> think of the middle letter 'M' --> as 'm'uscles 

Describe the muscle movements shown in the different stages of sleep (REM, N1, N2, N3)

• During REM sleep, EMG readings show low activity, due to there being low levels of physiological activity (body paralysis) during this type of sleep 

• During NREM sleep, EMG readings show medium/moderate activity, due to there being some physiological activity during this type of sleep --> however, as NREM sleep stages progress, an EMG is likely to show lower activity as movement is less likely to occur (although it is still possible) 

• Electro-oculography (EOG) 

• How is this measured/used

An electro-oculograph (EOG) is a device that detects, amplifies, and records the electrical activity of the muscles responsible for eye movement/around the eye 

• The movement of these muscles, and therefore movement of the eyes, is measured by electrodes that are attached to the skin above the muscles 

• TIP: To remember what EOG measures --> think of the middle letter 'O' --> as 'o'ccipital 

Does EOG detect, amplify and record electrical activity of eyes?

No. The EOG detects, amplifies, and records electrical activity of muscles surrounding the eyes, and uses this to infer eye movements. In order to gain full marks, it is essential that you state 'muscles surrounding the eyes'.

Describe eye movement in the different stages of sleep

Eye movements, which are facilitated by the movements of muscles surrounding the eyes, are a physiological response that can be used to investigate the type of sleep a person is experiencing 

• During REM sleep, an individual experiences rapid eye movement, so an EOG is likely to show high activity 

• During NREM sleep, an individual does not experience rapid eye movement, so an EOG is likely to show low activity 

• Sleep diaries

• What sort of information do they include:

• Examine their relability/usefullness

Sleep diaries are a record containing subjective self-reported descriptions from an individual about their sleep and waking patterns, including judgements they might have about the quality and nature of their sleep 

• It can include both qualitative and quantitative data 

• This information is recorded over a period of time, most commonly a few weeks 

 

Some of the information that can be recorded by an individual in a sleep diary include:  

• The duration of sleep – time spent asleep --> waking and sleeping time 

• the quality of sleep  

• thoughts and feelings before going to sleep  

• thoughts and feelings after waking up  

• behaviours before going to sleep  

• behaviours after waking up  

• the number of times sleep was disrupted + sleep disturbances 

 

Other info 

• Food intake 

• Caffeine intake 

• Daytime naps 

• Exercise throughout the day 

• Use of screens before bed 

 

• Sleep diaries are beneficial as they provide qualitative information and therefore are often extensive in detail and description 

• This method is subjective and therefore can be less reliable/accurate than objective measures 

Video monitoring 

Video monitoring involves the use of camera and audio technologies to record an individual as they sleep 

• This provides data specific to the individual to track their sleeping and waking periods, their movements and activities when sleeping, sleep positions, and the sounds they make while sleeping (e.g. sleep talking, teeth grinding) 

• The interpretation of video monitoring is subjective 

• Biological rhythms

• Circadian rhythms

• Sleep-wake cycle + is it a type of circadian rhythm?

• Examples of circadian rhythms

Biological rhythms are repeated biological processes that are regulated by internal mechanisms 

Circadian rhythms are biological occurrence where one complete cycle has a duration of 24 hours 

The sleep-wake cycle is a 24-hour-cycle that is made up of time spent sleeping and time being awake and alert 

• It is a type of circadian rhythm  

 

Other examples of circadian rhythms: 

• Release of melatonin 

• Release of cortisol 

• Body temp 

• Secretion of growth hormone 

• Ultradian rhythms

• Examples of ultradian rhythms

Ultradian rhythms are biological occurrence with a duration of less than 24 hours  

TIP: You can remember it as 'U'ltradian as 'U'nder 24 hours  

• A sleep cycle is an example of an ultradian rhythm as sleep cycles involve changes in physiological activity that repeat in a cyclic manner in less than 24 hours 

Suprachiasmatic nucleus (SCN) + it’s function

The suprachiasmatic nucleus (SCN) is an area of the hypothalamus that is responsible for regulating an individual’s sleep-wake patterns 

• Considered as the body's master clock 

 

The SCN receives information from both external and internal cues to help modulate the circadian rhythm 

• External cues involve information from the environment, such as the presence or absence of light 

• Internal cues involve information that originates within the body (such as the expression and suppression of particular genes, known as clock genes) 

• Melatonin

• How does SCN help assist the secretion of melatonin?

• When is melatonin typically secreted?

Melatonin is a hormone released by the pineal gland typically at night time to induce feelings of sleepiness as part of the sleep-wake cycle 

The information from our internal cues and external cues dictate the messages that the SCN sends to the pineal gland, which is a gland in the brain responsible for the production and release of melatonin

--> at night, when dark, greater quantities of melatonin are released 

--> during day, when it is light, very little melatonin is released 

 

Typically: 

• At around 8 to 9pm, melatonin levels should reach a level that starts to induce a sense of calmness, which promotes sleepiness, leading to an individual naturally wanting to induce sleep at around 10 to 11pm 

•  Melatonin peaks between 2 and 4am, when individuals are typically in the deepest sleep, before gradually declining over the night and before waking in the morning 

• T or F? Melatonin directly induces sleep

• T or F? SCN releases melatonin

1. False.

Melatonin does not directly induce sleep, but rather promotes a state of calm and relaxation/sleepiness to help make it easier to fall asleep where it travels to all areas of the body via the bloodstream 

2. False

The SCN does not actually release melatonin —> It is only responsible

for sending neural messages to the pineal gland, which enables the pineal gland to release melatonin

• Therefore, when answering questions about the role of the SCN in the sleep-wake cycle, you should make sure you do not write that SCN releases melatonin, but rather that the SCN signals to the pineal gland to release melatonin.

Cortisol + how does it help regulate the sleep-wake cycle

Cortisol is a hormone that is responsible for increasing alertness and maintaining heightened arousal 

• It also helps regulates the sleep-wake cycle as it is released by the adrenal glands (specifically adrenal cortex) in the morning to promote wakefulness and alertness 

Using this graph, comment on what changes occur:

As could be seen above: 

• Sleep duration and the proportion of REM sleep generally decreases as age increases 

• However, these trends occur at different rates as the proportion of REM sleep stops significantly decreasing from childhood onwards 

For babies/toddlers (0 - 24 months) - comment on their sleep

(Talk about hours of sleep, proportion of sleep episode which is REM and NREM, muscle movement and more)

Neonatal period (1–15 days)	Sleep duration is the highest it will ever be in the lifespan  New-born babies sleep for approximately 16 hours  Approximately 50% of the sleep episode is REM sleep and approximately 50% is NREM sleep  Each sleep episode may last from 30 min to 3 or 4 hours
Infancy (3–24 months)	Sleep duration decreases to approximately 13.5 hours (14-15 hrs)  The proportion of REM and NREM sleep also changes to approximately 35% REM sleep and approximately 65% NREM sleep  Sleep onset now begins with NREM sleep where previously newborns sleep onset began with REM sleep Muscle paralysis during REM sleep is established at 6 months, where prior, their arms and legs may move in REM sleep

For childhood (2-14 yrs) - comment on their sleep

(Talk about hours of sleep, proportion of sleep episode which is REM and NREM, NREM sleep stage which is abundant and more)

Childhood (2–14 years)

Sleep duration decreases again to approximately 11 hours (13 – 11 hrs) - (8 – 13 hrs)  The proportion of NREM sleep increases slightly to around 80% of the sleep episode, while REM sleep decreases to approximately 20% (20 – 25%) of the sleep episode  Experience an abundance of N3 sleep – about half of NREM is slow wave sleep  There are slight variations across this period

For adolescence (14–18 years) - comment on their sleep

(Talk about hours of sleep, proportion of sleep episode which is REM and NREM, NREM sleep stage time and more)

Adolescence (14–18 years)

Sleep duration decreases again to approximately 9 hours   The proportion of REM and NREM sleep remains fairly constant at 20% REM and 80% NREM sleep  Amount of N3 sleep progressively declines  Time spent in N2 sleep increases  Adolescents also experience a biological delayed sleep onset by 1–2 hours, meaning they are more likely to become sleepier later and wake up later

For adulthood (18 –75 years) - comment on their sleep

(Talk about hours of sleep, proportion of sleep episode which is REM and NREM, N3 sleep and more)

Young adulthood (18–30 years)	Sleep duration decreases again to approximately 7.75 hours (7 – 8 hrs)  The proportion of REM and NREM sleep remains fairly constant at 20 – 25% REM and 80% NREM sleep  Gradual loss of N3 sleep
Middle adulthood (30–75 years)	Sleep duration remains at approximately 7–8 hours  The proportion of REM and NREM sleep remains fairly constant at 20% REM and 80% NREM sleep

For old age(75+ years) - comment on their sleep

(Talk about hours of sleep, proportion of sleep episode which is REM and NREM, sleep disorders/problems and more)

Old age (75+ years)

Sleep duration continues to decrease to approximately 6 hours  The proportion of REM and NREM sleep remains fairly constant at 20% REM and 80% NREM sleep  Eventually N3 sleep disappears altogether  Older adults tend to experience advanced sleep phase syndrome, which is a biological shift forward in their sleep-wake cycle, meaning they become sleepier earlier and wake up earlier    Elderly may find deterioration in quality of sleep (increased night-time awakenings, need to go toilet more often, medical problems) + difficulty falling asleep at night

• T or F? It's a misconception that we require less sleep when we age – sleep needs to remain constant throughout adulthood, yet elderly are receiving less 

• Showcase the sleep requirements for healthy functioning and the average hrs slept by each age group

• T. It's a misconception that we require less sleep when we age – sleep needs to remain constant throughout adulthood, yet elderly are receiving less 

• Sleep deprivation

• Full sleep deprivation

• Partial sleep deprivation

Sleep deprivation describes a state caused by inadequate quantity and/or quality of sleep 

• Quantity is about how many hours of sleep is experienced  

• And quality is about how well one slept including the types of sleep experienced, as well as the presence of sleep disruptions 

 

Full sleep deprivation is when an individual has no sleep within a 24-hour-period 

 

Partial sleep deprivation is when an individual sleeps for some duration within a 24-hour-period, but the sleep duration is too short, or the quality of sleep is poor 

Causes of sleep deprivation 

• Emotional stress or excitement 

• Medical conditions and medication 

• Food, caffeine, drugs or alcohol 

• Work, school requirements 

Physiological effects of sleep deprivation

• Affective effects

• Some affective effects of sleep deprivation include

Affective effects refer to the changes in emotions and emotional responses that arise from sleep deprivation 

 

Some affective effects of sleep deprivation include:  

• Poor emotional regulation; resulting in amplified emotional responses that are out of proportion (exaggerated) in comparison to normal emotional responses  

• Irritability and moodiness (mood swings) 

• Lack of motivation 

• Increase in negative emotions  

• Reduced ability to cope with stress 

• Difficulty judging other people’s emotions  

• Reduced empathy towards others  

• Impaired ability to appropriately respond to situations; thus, people may overreact (emotionally) to minor things and experience emotional outbursts  

• Increase in aggression and impatience  

• Heightened anxiety

• Feelings of fatigue

• Behavioural effects

• Some behavioural effects of sleep deprivation include:  

Behavioural effects refer to the changes in actions and the ability to control them that arise from sleep deprivation 

 

Some behavioural effects of sleep deprivation include:  

• Sleep inertia (sense of disorientation after waking)  

• excessive sleepiness during the day  

• increased likelihood of engaging in risk-taking behaviours  

• fatigue/lack of energy 

• slowed reaction time  

• reduced efficiency/productivity; thus, it takes more time to complete tasks – reduced speed & accuracy 

• reduced motor control and heightened clumsiness, contributing to higher rates of accidents and injuries 

• involuntary lapses into microsleeps (where the individual briefly falls asleep for a few seconds without awareness of doing so) 

• diminished social functioning and impaired control of behaviour 

• Cognitive effects

• Some cognitive effects of sleep deprivation include:  

Cognitive effects refer to the changes in mental processes that arise from sleep deprivation – thinking, planning, reasoning, learning and memory 

 

Some cognitive effects of sleep deprivation include:  

• reduced concentration/attention 

• Memory lapses (failure, mistake) 

• diminished ability to perform cognitive tasks, particularly as the duration of the task increases 

• impaired decision-making processes and problem-solving abilities + reduced ability to make decisions quickly and effectively 

• diminished creativity and ability to utilise abstract thought/impaired abstract thinking

• Difficulty processing information

• irrational and/or illogical thinking  

• reduced speed in processing and understanding information 

• more time spent analysing situations and a greater likelihood of overlooking important details 

• impaired visual and spatial ability - Distorted perception

• Difficulty dividing attention

• Memory problems

REM Rebound

• Blood alcohol concentration (BAC)

• Alcohol is a depressant drug. What does this mean?

Blood alcohol concentration (BAC) is a measure of how much alcohol is in a person’s bloodstream 

•  If a person’s BAC is 0.05, there are 0.05 grams of alcohol for every 100 ml of blood in that person’s body 

 

• Because alcohol is a depressant drug, it will slow down the nervous system and decrease alertness, concentration, reflexes, and decision-making 

• A BAC of 0.05 is roughly equivalent to ___ hours of sleep deprivation (___ sleep deprivation) 

• A BAC of 0.10 is roughly equivalent to ___ hours of sleep deprivation (___ sleep deprivation) 

• A BAC of 0.05 is roughly equivalent to 17 hours of sleep deprivation (partial sleep deprivation) 

• A BAC of 0.10 is roughly equivalent to 24 hours of sleep deprivation (full sleep deprivation) 

Both sleep deprivation and alcohol alter an individual’s emotional state when compared to how the individual typically experiences emotions. Talk about how:

• Generally speaking, sleep deprivation negatively affects someone’s emotional functioning, making them more irritable or sensitive while alcohol can have a range of effects on someone’s emotions, including making them feel: happy and excited, angry, sad 

• In the short-term, alcohol is more likely to have a range of emotional effects as previously described + however, in the long-term, alcohol is more likely to have a dulling effect on emotions as it is a depressant drug 

Sleep disorders

Sleep disorders are disturbances to typical sleeping and waking patterns 

• Circadian rhythm sleep disorders

• Causes of circadian rhythm sleep disorders 

• Effects of circadian rhythm sleep disorders 

Circadian rhythm sleep disorders are sleep disorders that involve a mismatch (or misalignment) between a person's sleep-wake cycle and a sleep-wake pattern/schedule which is desired/required 

Causes of circadian rhythm sleep disorders 

• They are fundamentally caused by a disruption to the typical sleep-wake cycle --> this can be due to a biological issue, such as the sleep-wake shift that occurs in adolescents, or lifestyle changes, such as shift work 

 

Effects of circadian rhythm sleep disorders 

They tend to result in an individual experiencing some form of sleep deprivation Therefore, an individual may experience:  

• amplified emotional responses 

• Excessive sleepiness 

• Insomnia (unable to fall asleep) 

• Fatigue 

• Irritability 

• reduced ability to concentrate 

 

Circadian rhythm sleep disorders can also be disruptive to an individual's lifestyle 

e.g. Sleeping and waking at abnormal times can result in an individual  

• being late for certain commitments 

• feeling sleepy at abnormal times, which makes it difficult to complete daily tasks 

• Delayed sleep phase syndrome (DSPS)

• When is melatonin released in this disorder

• To be diagnosed with DSPS, a person needs to experience symptoms for how long?

Delayed sleep phase syndrome (DSPS) is a type of circadian rhythm sleep disorder characterised by a later sleep onset time and a later awakening time compared with the time that is desired/accepted/conventional

• In this way, the sleep-wake cycle is delayed – where melatonin is released later 

• Sleep is usually 2 or more hours later than needed/acceptable 

• To be diagnosed with DSPS, a person needs to experience symptoms for more than 3 months 

• e.g. if an individual typically starts sleeping at 10pm and wakes at 8am, with DSPS they may instead start sleeping at 1am and wake at 11am 

Advanced sleep phase disorder (ASPD) + when is melatonin released in this disorder

Advanced sleep phase disorder (ASPD) is a type of circadian rhythm sleep disorder characterised by an earlier (advanced) sleep onset time and an earlier (advanced) awakening time, compared 

with what is desired/accepted/conventional

• In this way, the sleep-wake cycle is advanced - where melatonin secretion occurs earlier

• Sleep is usually 2 or more hours later than needed/acceptable 

• e.g. if an individual typically sleeps at 10pm and wakes at 8am, with ASPD they may sleep at 7pm and wake at 5am 

Why are ASPD and DSPS considered as disorders?

It becomes a disorder because the sleep schedule can interfere with daily life. 

For example for ASPD:

• They become extremely sleepy in the early evening and may struggle to stay awake for dinner, social events, or homework.  

• They wake up very early (e.g. 4–5 am) and cannot fall back asleep, even though they don't need to be awake yet.  

• Their sleep schedule doesn't match school, work, or family schedules 

 

e.g. In DSPS: 

• They cannot fall asleep early, even if they go to bed at 10 pm because their body isn't ready to sleep yet.  

• They struggle to wake up early for school or work  

• They may be tired and sleepy during the morning 

• Their sleep schedule doesn't match school, work, or family schedules, making it difficult to function during normal daytime hours 

• Shift work  

• Examples of jobs that involve shift work

• Shift work disorder

Shift work is an occupation that involves working at unusual hours, such as working overnight 

• This can mean an individual has to sleep at unusual times, such as during the day, rather than at night. 

• Shift work schedules include day shift, afternoon shift and night shift 

• When workers are rostered for the same shift for their work (a fixed schedule) 

• Shift work also involves rotating shift work, which may involve working a week of morning shifts, followed by a week of night shifts – shifts are at different times 

• Some occupations that involve shift work include nurses, road workers, hotel staff, paramedics, police, fire fighters, airline staff, pilots and drivers 

 

Shift work disorder: when scheduled work hours are out of sync with their natural circadian rhythm 

Shift work effects include:

• Insomnia (a sleep disorder characterised by difficulty falling asleep and staying asleep) 

• Fragmented sleep - shift work often involves working unusual hours and therefore having to sleep at unusual hours --> this can involve repeatedly waking up during a sleep episode and having multiple short sleep episodes during the day (naps), as opposed to one regular sleep episode (approximately 8 hours) 

• Shift work disorder 

• Feel sleepy during their work shift 

• More vulnerable to workplace accidents or errors 

• Partial chronic sleep deprivation 

• Quality and quantity of sleep can be adversely affected 

Tips for shift workers 

• Be rostered on only one shift schedule to allow circadian rhythms to adjust 

• Try to stay on one shift schedule for as long as possible 

• Better if day shift is followed by afternoon shift, or afternoon shift is followed by evening shift 

• Eat regular, healthy meals and avoid hard-to-digest food before bed 

• Avoid caffeine and stimulants 6 hrs before they plan to go to bed 

• Exercise regularly 

• Ensure sleeping environment is conclusive to sleep (dark room, cool room temp, earplugs and wear eye mask) 

• Wear sunglasses when driving home from night shift to avoid morning light 

Bright light therapy + how often does it occur/sessions length

Bright light therapy is a method used to shift a person’s sleep-wake cycle to a desired schedule through timed exposure to the eyes of intense but safe amounts of light 

 

• Change occurs over a period of time involving multiple sessions of bright light therapy  

• Exposure sessions can last from about 15 minutes to a couple of hours and are conducted up to a few times a day (once or twice) + In order to readjust the sleep-wake cycle, a person needs to conduct these sessions for at least a few consecutive days 

Bright light therapy for the different types of sleep disorders  

Delayed sleep phase syndrome	Conduct an exposure session early in the morning   --> this acts as an external cue to the suprachiasmatic nucleus (SCN), signalling that it is daytime - this suppresses melatonin production and promotes the release of cortisol, helping the person feel awake/energised    This will help the SCN send signals for melatonin to be released earlier in the evening, helping the individual become sleepy earlier and fall asleep at a more appropriate time
Advanced sleep phase disorder	Conduct an exposure session in the late afternoon or early evening  --> this acts as an external cue to the suprachiasmatic nucleus (SCN), signalling that it is still daytime - this delays melatonin production and promotes wakefulness    This will help the SCN send signals for melatonin to be released later at night and cortisol is released later in the morning, helping the individual stay awake longer and fall asleep and wake up at more appropriate times
Shift work related sleep disorder	An individual is best to be exposed to the bright light source before beginning their shift work  -->  as this t exposure acts as an external cue to the suprachiasmatic nucleus (SCN), signalling that it is daytime - this promotes the release of cortisol, increasing alertness and helping the individual stay awake during their shift     Over time, the SCN adjusts the timing of melatonin release so that the individual becomes sleepy after their shift/more suitable time, making it easier to sleep during the day when they are not working

• Sleep hygiene

• Mental wellbeing - it’s relationship to sleep

Sleep hygiene healthy habits and practices to optimise getting to sleep when desired and achieving the quality and quantity of sleep required for good mental health and wellbeing  

• It is positive and beneficial, as it improves the quality and quantity of sleep 

Mental wellbeing is an individual’s psychological state, involving their ability to think, process information, and regulate emotions 

• Research suggests there is a link between poor sleep (sleep deprivation and/or sleep-related problems) and mental illness 

• Thus, good sleep is likely to reduce the likelihood of mental health problems and promote mental wellbeing 

• The relationship between sleep and mental wellbeing is bidirectional, meaning that sleep can impact mental wellbeing and mental wellbeing can impact sleep 

How to uphold sleep hygiene (talk about time, sound, light, technology, association with bed, temp, food & drink consumption, exercise)

• time; sleeping and waking at a time that enables an adequate amount of sleep, and sleeping and waking at a consistent time each day 

• sound; sleeping in a fairly quiet space 

• light; sleeping in a dark space and reducing bright light exposure close to sleeping time 

• comfort; sleeping in a comfortable space 

• technology/devices; avoiding bright screen use close to sleeping time 

• association with bed; avoiding doing activities other than sleeping in bed (like studying or watching TV) 

• Temperature; cool temp 

• food and drink consumption; avoiding large meals, caffeine, and alcohol before sleeping time 

• exercise; engaging in exercise early in the day and avoiding exercise close to sleeping time 

• Zeitgebers

• Endogenous factors

• Examples of Zeitgebers

Zeitgebers are external cues from the environment that influence the circadian rhythm/provide signals to our brains to do things at certain times 

• German word for 'time givers' 

• Sleep-wake patterns can be improved when individual is exposed to the correct zeitgebers at the appropriate times to optimise sleep 

 

Endogenous factors means originating or growing from within an organism, system, or body – internal factors 

• Blue light + it’s sources

• Daylight

• How light affects sleeping patterns

• How to utilise light to improve sleep

• Blue light is a type of light that can be emitted both naturally and artificially 

  • Its artificial sources include technological devices such as laptops, tablets, television and phones 

   

• Daylight is the typical light an individual is exposed to during the day, and is mostly natural blue light (it has a short wavelength) 

 

• Daylight acts as a zeitgeber as it regulates the sleep-wake cycle by signalling to the suprachiasmatic nucleus (SCN) to cease melatonin production and promote wakefulness 

• Artificial blue light can also act as an external cue in the same way that daylight does, thus promoting wakefulness – and so exposure to natural or artificial blue light at night time can reduce sleepiness 

 

• So limit exposure to 'blue light' a couple hours before bed, sleep onset will be easier to achieve 

  • If unavoidable to view screens in the evening (due to finishing HW/work commitments) then changing brightness of screens to warmer tones may assist 

Explain how temp affects sleep:

• There is a link between having a cool room temperature and experiencing improved quantity and quality of sleep --> it is thought that this is because body temperature drops during sleep, thus, a cooler room temperature helps body temperature cool 

• Research contends that 18.3 degrees Celsius is an ideal room temperature for sleep 

• Extreme temperatures (very high or very low) are not good for sleep quality and quantity 

• Body temp does not vary significantly, so a small change can have a large effect 

• Eating and drinking patterns

• Explain why one shouldn’t eat too late at night/near bedtime or in early hours in the morning 

Eating and drinking patterns refer to what, when, and how much food and drink is consumed by an individual 

 

The circadian system prepares the body to be more efficient at digesting, absorbing and metabolising food earlier in the day, when one is more active 

• For instance, insulin sensitivity (regulates blood sugar) is greater in the morning – meals are better processed when eaten in the first half of the day 

• Since melatonin is released at night, reduces insulin release – body is unable to process sugars properly when eat late at night or early in the morning (when melatonin is high) 

 

• Hence one should not eat too late at night or in early hours in the morning 

Explain how these foods affect the quality and quantity of sleep:

• caffeine  

• alcohol  

• spicy foods 

• high-sugar and high-fat foods 

caffeine	Caffeine is a stimulant and thus increases the activity of the nervous system, promoting wakefulness  caffeine also blocks sleep-promoting neurotransmitters.  It can be found in coffee, energy drinks, some soft drinks, and chocolate
alcohol	Alcohol is a depressant which can increase feelings of tiredness --> hence alcohol can make it easier to fall asleep  however, alcohol significantly impairs the quality of sleep --> where it often negatively impacts sleep in the second half of the sleep episode, in which sleep disruptions are more common
high-sugar and high-fat foods	Studies suggest that consuming a diet high in fatty foods and sugary foods can negatively impact sleep quality and quantity
spicy foods	Spicy foods can increase body temperature --> while cooler body temperatures can promote sleep --> hence the increased body temperature from consuming spicy foods can impair sleep  Spicy foods can stimulate and increase metabolic processes, which can make it more difficult to fall asleep

The amount of food we eat can also influence sleep quality and quantity, where:

• Specifically, going to sleep feeling hungry can lead to poorer sleep quality and quantity 

• Eating large meals close to sleep time and going to sleep overly full can impair sleep patterns 

What is rem and nrem sleep respoinsible for?

• NREM (Non-Rapid Eye Movement) sleep is mainly responsible for:

  • Physical restoration and repair of the body (e.g. muscle growth and tissue repair).

  • Conserving energy.

  • Strengthening the immune system.

  • Some consolidation of declarative memories (facts and events), especially during deep NREM sleep.

• REM (Rapid Eye Movement) sleep is mainly responsible for:

  • Cognitive restoration (restoring brain function).

  • Memory consolidation, particularly procedural (skills) and emotional memories.

  • Processing emotions.

  • Most vivid dreaming.