UNIT 4 AOS 1 PSYCH - sleep

Consciousness

The subjective awareness of your own mental processes, including thoughts, feelings, sensations and awareness of the external world around you.

PSYCHOLOGICAL CONSTRUCT BECAUSE:

It cannot be objectively observed or measured through the collection of data, but is widely understood to exist. It is impossible to know what others are experiencing.

Psychological construct

A concept that cannot be objectively observed or measured directly through the collection of data but is widely understood to exist.

Normal waking consciousness NWC

A state associated with being aware of our internal and external environments

• awake and have a regular level of awareness

• can manage attention and behaviour

• thoughts and perceptions are clear

EG) reading a book, chatting, having dinner

Altered state of consciousness

Any state that differs in awareness compared to NWC, either higher or lower levels.

A change in mental processing where perceptions/thinking may be altered.

• naturally occurring or induced

Naturally occurring altered state of consciousness

An altered state of consciousness that occurs without any external influence

• (sleep, flow state, fatigue)

Induced altered state of consciousness

An altered state of consciousness that has been brought about on purpose

• (alcohol, anaesthesia)

Sleep

A reversible behavioural state of unawareness, unresponsiveness and disengagement from the external environment.

NREM Non-Rapid Eye Movement

Type of sleep characterised by a progressive decline in physiological activity.

• 3 stages (N1, N2, N3)

• takes up around 80% of the sleep cycle in people school-aged +

N1- transactional phase between wakefulness and sleep

N2- light sleep where psychological processes slow

N3- deep sleep, where psychological processes are the slowest (slow wave sleep), most difficult to wake

NREM N1

transactional phase between wakefulness and light sleep

• HR, body temp and brain activity begin to slow

• can be easily woken up

• quickly moves into N2

NREM 2

light sleep, where psychological responses continue to slow down

• still can wake relatively easily

• Bursts of brain activity help resist being woken by environmental stimuli

• stage that experienced the most throughout a sleep episode

NREM 3

Deep sleep, where psychological responses are at their slowest

• most difficult to wake up

• slowest brain activity ( aka: slow-wave sleep)

• experienced more in the first half of the night than the second.

• As an episode progresses, a person experiences less N3 sleep, towards the final 1-2 cycles, possibly none at all

• body repairs itself

REM Rapid Eye Movement

Type of sleep characterised by quick darting of the eyes behind closed eyelids and an increase in psychological activity.

• brain activity resembles wakefulness

• HR and RR increase

• voluntary muscles are seemingly paralysed

• Most vivid and memorable dreams occur

• Periods occur at the end of each sleep cycle (gets longer and closer together as the episode progresses)

• More REM in the second half of the sleep episode

• differs across ages

• typically 20% of sleep episodes

• Mind repairs itself

Electroencephalography EEG -objective

A technique that detects, amplifies and records electrical activity of the brain.

• attached to a peroso’s scalp

• brain wave recordings produced by EEG are summaries of the activity of thousands of neurons in the area

Electromyography EMG -objective

A technique that detects, amplifies and records the electrical activity of muscles.

• records strength of electrical activity occurring in muscles, which indicates a change in tone and activity - higher levels = more alert we tend to be

• Attached to skin above any muscles of interest

Electro-oculargargraph EOG - objective

A technique that detects, amplifies and records the electrical activity of eye muscles that control eye movements.

• used to measure changes in eye movements, particularly in REM

• electrodes attached to skin at the side of the eyes

Sleep diaries - subjective

Self-reported records of an individual’s sleep and waking time activities, patterns and habits.

Video monitoring - subjective

A sleep study tool used to collect qualitative visual and audio information about a person’s sleep.

• posture

• tossing/turning

• sleep walking/talking

Regulation of sleep wake patterns

TWO TYPES;

• circadian rhythm

• ultradian rhythm

biological rhythms that are controlled by biological mechanisms involving cyclic changes in bodily functions that repeat over time in the same order.

Circadian rhythm

Biological processes that coordinate the timing of body activities over a 24-hour period

• controls sleep-wake cycle, release of hormones, and regulation of body temp

• develops and undergoes changes over the lifespan

Ultradian rhythm

Biological processes that coordinate the timing of body activities over a period less than 24 hours

• cycle repeatedly over the day

• HR, digestion, BP, appetite

• sleep cycles = ultradian rhythms

Suprachiasmatic nucleus SCN

The master body clock in the hypothalamus which regulates body activities to a daily schedule of sleep/wake

• sends signals to regulate activities in the body and keep it functioning to a daily sleep-wake schedule.

• sensitive to light

• influenced by zeitgebers

Zeitgebers

An environmental cue that can regulate the body’s circadian rhythm

(light, temp, eating patterns)

Melatonin

A hormone that induces drowsiness and decreases cell activity.

• When the eyes don’t detect light, the SCN sends messages to the pineal gland to release melatonin.

• ensures sleep is connected to nighttime

• allows circadian rhythms to be synchronised with the outside world and create stable cycles that enable you to feel awake during the day and fall asleep at night

Sleep across the life span

Newborns 14-17 hrs/ REM 50%- don’t have an established circadian rhythm, erratic sleeping patterns, and sleep distributed across the 24h day. require highest amount of sleep for rapid growth and development.

Infants (4m+) 12-16hrs/ REM 30-60% - Sleep becomes more nocturnal and develops a fairly consistent circadian rhythm.

Adolescents 8-10hrs/ REM 20% - experience a shift in circadian rhythm due to a hormonally determined shift in melatonin release ½ hours later than other age groups, which can result in a delayed sleep phase syndrome due to not feeling tired until later in the evening.

Adult 7-8hrs/ REM 20% - After adolescence, the circadian rhythm returns to a more normal timing, and most experience a consistent rhythm if following a regular routine. N3 begins to decline, replaced by N2 sleep. melatonin concentrations decline over adulthood

Old adults 7-8hrs/ REM 18-20% - May prefer an earlier bedtime, therefore waking earlier in the mornings.

Lifestyle, health issues, decreased social interactions and increased medication use can alter sleep patterns.

Partial sleep deprivation

The experience of inadequate sleep in terms of quality and quantity can cause negative effects on a person’s ABC functioning

Factors contributing:

• consuming food, caffeine, drugs, alcohol

• work/school

• stress

• medical conditions

• uncomfortable sleeping environment

• social influences

Affective functioning

A person’s experience of their emotions.

when sleep deprived, there may be:

• Trouble regulating/controlling emotions

• mood swings/emotional bursts

Behavioural functioning

A person's observable actions.

When sleep deprived, there may be :

• trouble controlling behaviour

• participation in more risk-taking or impulsive behaviour

• take longer to finish tasks

• reduced productivity/efficiency

• reluctant to get out of bed in the morning

• hyperactivity/misbehaviour

Cognitive functioning

A person’s mental processing.

When sleep deprived, you may experience these cognitive functioning issues:

• trouble with memory and coping with stress

• decreased alertness

• poor concentration and judgment

• impaired problem-solving and decision-making

• lack of motivation.

• difficulty learning

• slower thinking/shorter attention

Comparing sleep deprivation to BAC - percentage of alchol in blood stream

Legal level for BAC is 0.05%,

• anything above that limit has detrimental effects on a person’s ABC functioning.

• Effects of 24hrs of wakefulness are equivalent to the effects of a BAC of 0.10%.

Circadian sleep rhythm disorders

Sleep disturbances caused by a mismatch between an individual's internal biological clock and the external environment’s required sleep-wake schedule

Types:

• shift work

• DSPS delayed sleep phase syndrome

• ASPD advanced sleep phase disorder.

treated by bright light therapy.

Bright light therapy

A therapy to treat a sleep disorder in which the person is exposed to bright light to reset the sleep/wake cycle.

DSPS - Delayed sleep phase syndrone

Circadian rhythm disorder where there is a delay in the timing of sleep onset and awakening compared with the timing that is desired.

ASPD- advanced sleep phase disorder

Circadian rhythm disorder where there is an advance in the timing of sleep onset and awakening compared to the desired timing.

Shift work

Work that regularly takes place outside of normal business hours, particularly night/early morning that can cause a Circadian rhythm disorder

Sleep hygine

Sleep-related behaviour and environmental conditions that are beneficial for sleep.

Zeitgebers (has examples)

An environmental cue that can synchronise and regulate the body’s circadian rhythm.

• blue light - screens

• temperature - ideal room temp - 19-21 °C

• eating and drinking patterns- the suprachiasmatic nucleus is affected by perceived starvation. Body clocks can be influenced by the timing of meals.