Psychology Unit 4 AOS 1

consciousness

awareness of something either internal or external to oneself, including objects and events in the external world, and of our sensations, mental experiences and own existence at any given moment

states of consciousness

a state of awareness with variations in level and associated with distinguishable psychological and physiological characteristics

normal waking consciousness (NWC)

state of consciousness associated with being awake and aware of objects and events in the external world, and of one’s sensations, mental experiences and own existence

altered state of consciousness

any state of consciousness that is distinctly different from NWC or any waking state in terms of level of awareness and experience

naturally occuring ASC

altered states of consciousness such as sleep, dreaming during sleep and daydreaming when awake, that are naturally occurring in the course of everyday activities without the need for any aid

induced ASC

a temporary change in one’s normal mental state without being considered unconscious, are intentionally brought on by the use of some kind of aid

sleep

a regularly occurring altered state of consciousness that typically occurs naturally and is primarily characterised by partial or total suspension of conscious awareness

psychological construct

a concept, description or explanatory model that describes specific psychological activity or a pattern of associated activities or processes that cannot be directly observed

electroencephalography (EEG)

is used to detect, amplify and record the electrical activity of neurons through electrodes manually placed at various points on the scalp.

beta waves

highest frequency, lowest amplitude, normal waking consciousness, awake, alert, focused

alpha waves

high frequency, low amplitude, lower alertness, awake but relaxed, quiet, calm, drowsy, low environmental stimulation

theta waves

low frequency, high amplitude, low alertness, light sleep, senses withdraw from external environment, deep meditation

delta waves

lowest frequency, highest amplitude, lowest alertness, deep N3 sleep, dreamless sleep

sleep diary

a self-report record of an individual’s sleep and waking time activities

video monitoring

recording externally observable physiological responses throughout a sleep episode, including behaviours when falling asleep and when waking

electromyography (EMG)

detects, amplifies and records the electrical activity of the skeletal muscles, electrodes are attached around the jaw and sometimes the legs or other body parts.

electro-oculargraphy (EOG)

detects, amplifies and records the electrical activity of the muscles controlling the eyes, electrodes are attached to the surface of the skin around the sides of each eye ​

biological rhythms

a naturally occurring cycle of physiological, psychological or behavioural changes

biological clock

innate timing that regulates one or more biological rhythms

circadian rhythm

biological rhythm involving physiological, psychological or behavioural changes that occur as part of a cycle with a duration of about 24 hours

endogenous

originating within an organism

exogenous

originating outside an organism

ultradian rhythm

a biological rhythm involving physiological, psychological or behavioural changes that occur as part of a cycle shorter than 24 hours

suprachiasmatic nucleus (SCN)

an area of the brain’s hypothalamus that regulates the timing and activity of the sleep–wake cycle and other biological rhythms

melatonin

a hormone secreted by the pineal gland in relation to the amount of light that is detected; influences alertness and drowsiness and timing of the sleep–wake cycle

NREM sleep

non-rapid eye movement sleep with three stages involving increasingly deeper sleep

REM sleep

rapid eye movement sleep

hypnogram

a sleep graph typically showing sleep types and stages in relation to time

sleep onset

the transition period from being awake to being asleep

sleep latency

the length of time it takes to transition from being awake to being asleep

NREM stage 1

A light sleep lasting a few minutes; person may experience hypnic jerks. Heart rate, body temperature, and muscle activity begin to slow.

NREM stage 2

A deeper stage of light sleep; body functions continue to slow. EEG shows sleep spindles and K-complexes. Person is less likely to respond to stimuli.

NREM stage 3

The deepest stage of sleep. Characterised by delta waves. Body is at its most restful—essential for physical recovery and growth.

changes throughout a night’s sleep

• Each cycle typically repeats 5–6 times per night, depending on total sleep time.​

• Each NREM–REM cycle lasts approximately 90 minutes.​

• NREM Stage 3 (deep sleep) is most common in the first half of the night, especially in the first two cycles.​

• As the night continues, NREM Stage 2 becomes the main NREM stage, and NREM Stage 3 may stop occurring.​

• The deepest sleep usually happens in the first third of the night.​

• REM sleep increases in duration as the night progresses, with the longest REM periods in the final third of the night.​

• Brief periods of wakefulness often occur in later cycles, usually during transitions between NREM and REM, but are generally not remembered.

reasons for sleep

• Sleep is necessary for repair and restoration of the body and mind, including repairing tissues, replenishing neurotransmitters and removing waste products. ​

• Sleep serves an adaptive function by giving us time to conserve energy and remain safe during times of potential danger, such as night-time for humans. ​

• Additionally, sleep allows for information acquired throughout the day to be processed and consolidated, aiding in memory and preparing us for the new day to come.

sleep as we age

• The total amount of sleep decreases.​

• The proportion of REM sleep decreases significantly from birth until 2 years old.​

• The amount of N3 sleep decreases, replaced mostly by N2 sleep.​

• A circadian phase delay occurs during adolescence (preference to go to sleeplater – this correlates with a naturally occurring delayed release of melatonin by 1to 2 hours).​

• After adolescence, a shift to a circadian phase advance occurs (preference forgoing to sleep earlier).​

• Awakenings during sleep increase from adulthood to old age.​

circadian rhythm changes-newborn

they do not have an established circadian rhythm. their sleeping patterns are erratic, with their sleep distributed across the full 24-hour day

circadian rhythm changes-infant

from about 4 months, sleep becomes more nocturnal. as they continue to develop and experience rapid physiological changes, they begin to have a fairly consistent circadian rhythm

circadian rhythm changes-adolescent

they experience a shift in their circadian rhythm; they may not feel tired until later in the evening. this can result in a delayed sleep phase syndrome

circadian rhythm changes-adult

the circadian rhythm returns to more normal timing, and most experience a consistent circadian rhythm if they are following a regular routine with relatively stable bedtimes and wake times

circadian rhythm changes-older adult

they may prefer an earlier bedtime and therefore an earlier waking in the morning

changes in sleep over the lifespan-newborn

stage of lifespan: 0-3 months
total recommended hours of sleep: 15-17 hours

typical proportion of REM & NREM: 50% REM, 50% NREM

explanations for sleep patterns:

• they require the highest amount of total sleep for rapid growth and development.​

• they experience the highest proportion of REM sleep, as REM sleep may boost brain growth and development, and help consolidate learning and memory. ​

• Sleep onset may occur at any time of the day or night, with no regular rhythm. ​

• Sleep duration also tends to be irregular. ​

• there are fewer sleep cycles.​

• By 3 months of age, the NREM–REM sleep cycles become more regular; more responsive to external cues.​
  

changes in sleep over the lifespan-infant

stage of lifespan: 4-11 months

total reccommended hours of sleep: 12-16 hours

typical proportion of REM & NREM: REM 30-40%, NREM 60-70%

explanations for sleep patterns:

• Their circadian rhythm develops a more regular sleep pattern following day–night cycles.​

• Sleep onset now begins with NREM stage 1, REM sleep decreases and shifts to the later part of the sleep cycle, and the total NREM–REM sleep cycle is typically 50 to 60 minutes.​

• By 6 months of age, total sleep time reduces slightly​

changes in sleep over the lifespan-toddler

stage of lifespan: 1-2 years

total recommended hours of sleep: 11-14 hours

typical proportions of REM & NREM: REM 25-30%, NREM 70-75%

explanations for sleep patterns:

• By about 12 months old, they sleep 14 to 15 hours per day ​

• in this stage, the proportion of REM sleep has had its greatest decline, and only decreases a small amount over the rest of the life span.

changes in sleep over the lifespan-preschooler

stage of lifespan: 3-5 years

total recommended hours of sleep: 10-13 hours

typical proportion of REM & NREM: REM 25%, NREM 75%

explanations for sleep patterns:

• The proportion of REM sleep continues to decrease and the amount of NREM sleep increases, with a greater percentage of sleep time spent in stages 2 and 3.

• About half the NREM sleep of children is stage 3 deep sleep and this decreases markedly from about age 10.​

changes in sleep over the lifespan-school age children

stage of lifespan: 6-13 years

total recommended hours of sleep: 9-11 hours

typical proportion of REM & NREM: REM 20%, NREM 80%

explanations for sleep patterns:

• From the early to late childhood years, the timing of the circadian rhythm gradually delays, and sleep shifts to later in the evening.

changes in sleep over the lifespan-adolescent

stage of lifespan: 14-17 years

total recommended hours of sleep: 8-10 hours

typical proportion of REM & NREM: 20% REM, 80% NREM

explanations for sleep patterns:

• they experience a delay in the circadian rhythm because of a hormonally determined shift in melatonin release to 1–2 hours later, can cause a preference for a later bedtime, resulting in fewer hours of sleep than needed because of early waking for school.​

• increasing school-related requirements, increasing independence and easy access to constant entertainment and social networks also contribute to delayed bedtime

changes to sleep over the lifespan- young adult

stage of lifespan: 18-25 years

total recommended hours of sleep: 7-9 hours

typical proportion of REM & NREM: REM 20%, NREM 80%

explanations for sleep patterns:

• can alter because of psychosocial factors such as tertiary study, work requirements, social schedules and increased independence.​

changes in sleep over the lifespan-adulthood

stage of lifespan: 26-64 years

total recommended hours of sleep: 7-9 hours

typical proportion of REM & NREM: REM 20%, NREM 80%

explanations for sleep patterns:

• later in this stage, N3 sleep begins to decline and is replaced by N2 sleep.​

• Melatonin concentrations continue to decline

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changes in sleep over the lifespan-older adult

stage of lifespan: >65 years

total recommended hours of sleep: 7-8 hours

typical proportion of REM & NREM: REM 18-20%, NREM 80-82%

explanations for sleep patterns:

• A circadian phase advance may occur, and less sleep may be achieved if a person resists the body’s preference for an earlier bedtime and earlier awakening.​

• Amount of N3 sleep continues to decline and may not occur at all, replaced with N2 sleep.​

• they tend to have a harder time falling asleep, sleep lightly, wake up more often and spend less time in deep, refreshing sleep than when they were younger.

• The prevalence of sleep disorders also tends to increase with age.

sleep disturbance

any sleep-related problem that disrupts an individual’s normal sleep–wake cycle

sleep disorder

any sleep disturbance that is persistent and regularly disrupts sleep, causing distress or impairment in important areas of everyday life during normal waking hours

primary sleep disorder

is a persistent sleep disturbance that cannot be attributed to another condition, such as another sleep disorder, a mental health or medical problem, or use of a legal or illegal drug.

secondary sleep disorder

involves a sleep disturbance that is a by-product of or results from another condition, or use of a substance.

sleep deprivation

inadequate quantity or quality of sleep

partial sleep deprivation

involves having less sleep (either quantity or quality) than what is normally required

total sleep deprivation

not having any sleep at all over a short-term or long-term period

sleep debt

the accumulated amount of sleep loss due to insufficient sleep

sleep inertia

a temporary period of reduced alertness and performance impairment that occurs immediately after awakening, especially after a poor night’s sleep and if abruptly awakened

microsleep

a very short period (e.g. a few seconds) of involuntary sleep

affective functioning

refers to a person’s experience of their emotions. ​When sleep deprived, you may have trouble regulating or controlling your emotions. ​You may experience mood swings or emotional outbursts, feel sad or depressed, be more irritable or cry for no apparent reason.

behavioural functioning

refers to a person’s observable actions. When sleep deprived, you may have trouble controlling your behaviour, participate in more risk-taking or impulsive behaviour, take longer to finish tasks, have reduced productivity, be reluctant to get out of bed in the morning or be more accident prone. Children may show hyperactive behaviour and increased misbehaviour. ​

cognitive functioning

refers to a person’s mental processing. when sleep deprived, you may have decreased alertness, poor concentration, impaired problem-solving, decision-making, poor judgement, lack of motivation, stress coping, difficulty learning new concepts, slower thinking, and a shortened attention span. This deterioration affects shift workers in jobs with significant health and wellbeing responsibilities.

blood alcohol concentration (BAC)

a measure of alcohol in the body expressed as grams of alcohol/100 mL of blood

cognitive effects

17 hours of full sleep deprivation= BAC 0.05% ​

24 hours of full sleep deprivation= BAC 0.10%.​

detrimental effects include poorer concentration, attention, decision making and problem-solving ability.​

affective effects of alcohol consumption compared to sleep deprivation

• sleep deprivation results in a negative mood state

• alcohol consumption results in either a positive or negative mood state, depending on the amount of sleep deprivation or alcohol, the individual and the context.​

• sleep deprivation, alcohol, cognition, concentration and mood are intertwined and may interact in complex ways in influencing conscious experience. ​

• affective effects include poorer emotional regulation, increased irritability and emotional outbursts

circadian rhythm sleep disorders

a sleep disorder involving sleep disturbance that is primarily due to a mismatch between an individual’s sleep–wake pattern and the pattern that is desired or required

delayed sleep phase syndrome (DSPS)

condition in which the major sleep episode is delayed in relation to the desired sleep time or what is considered a conventional time

advanced sleep phase disorder (ASPD)

circadian rhythm sleep disorder characterised by a shift of the major sleep episode to an earlier time compared to desired or conventional sleep times, resulting in sleep onset and awakening much earlier than desired and excessive sleepiness

shift work disorder

circadian rhythm sleep disorder due to work shifts being regularly scheduled during the usual sleep period; work shifts overlap with all or part of the sleep period, requiring adjustment of sleep and wake times to the work times

bright light therapy

a technique for treating circadian rhythm sleep disorders that uses timed exposure of the eyes to light with the aim of shifting an individual’s sleep-wake cycle to a desired, more appropriate or conventional schedule