Psych - U4 AOS 1

consciousness

consciousness

the level of awareness an individul has of their thoughts, feelings, perceptions and existence

psychological construct

an agreed upon description and understanding of psychological phenomena that cannot be overtly measured or observed

normal waking consciousness (NWC)

a state of consciousness in which an indiv. is awake and aware

• e.g reading a book, chatting with a friend, eating dinner w/ the fam

altered state of consciousness (ASC)

a state of consciousness that is distinctly different from NWC in terms of quality of experience and levels of awareness

• e.g daydreaming, drug-induced ASCs - like alcohol or anesthetic

naturally occurring altered states of consciousness

a type of altered state of consciousness that occurs w/out intervention

• e.g sleep, daydreaming

induced ASC

a type of altered state of consciousness that occurs due to a purposeful action or aid

e.g alcohol-induced state, anaesthetised state for a surgery or a meditative state

consciousness continuum

a visual representation of different states of consciousness that progress from lower levels of awareness to higher levels of awareness

biological rhythms

repeated biological processes that are regulated by internal mechanisms

circadian rhythms

biological and behavioural changes that occur as part of a cycle that lasts around 24 hours

• sleep-wake cycle

sleep-wake cycle

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

pineal gland

a gland in the brain responsible for the production and release of melatonin

melatonin

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

• typically levels of this hormone will be higher at night - and lower in the morning

suprachiasmatic nucleas (SCN)

an area of the hypothalamus that is responsible for regulating an individual’s sleep-wake patterns

• receives internal (clock genes - expression + suppression of particular genes) and external cues (presence/ absence of light) about when it is the appropriate time to send signals to the pineal gland to release melatonin.

• closely linked with day and night - sensitive to light

• relies on both external and internal cues - even in the presence of light, internal cues can help maintain some level of circadian rhythm

SCN process

1. SCN receives external + internal cues

2. SCN sends neural msgs to the pineal gland - produce and release meltonin

3. pineal gland releases melatonin into the bloodstream → feelings of clam and relaxation - promoting sleep!

Ultradian rhythm

biological and behavioural changes that occur in a cycle that lasts less than 24 hours

• sleep cycles made up of REM and NREM sleep

• e.g One 90-minute sleep cycle

• occur repeatedly in a cycle that lasts less than 24 hours

cortisol

a hormone that is responsible for incresing alterness and maintaining heightened arousal

• in sleep-wake cycle: promotes wakefulness in the morning when released by the adrenal cortex

Zeitgeber

external cues that influence the SCN and therefore the regulation of the circadian rhythm: exercise, social activity, eating patterns, temperature

sleep

a regular and naturally occuring altered state of consciousness that involves a loss of awareness and disengagement with internal and external stimuli

REM (rapid eye movement) sleep

a type of sleep characterised by rapid eye movement, high levels of brain activity and low levels of PA

• also v levels of biological activity

• experience muscle paralysis

• experience vivid dreaming

NREM (non-rapid eye movement) sleep

a type of sleep characterised by a lack of rapid eye movement and is subdivided into 3 different substages

sleep episode

the full duration of time spent asleep

sleep cycle

an approx. 90-min period that repeats during a sleep episode in which an indiv. progresses through stages of REM and NREM sleep

comparison of REM & NREM

REM:

• highly active brain - less active body

• virtually paralysed - most muscle movement is not possible

• relatively light stage of sleep - can be woken easily

• vivid dreaming - can recall when woken during REM sleep

• makes up 20-25% sleep episode for most age groups

• ^ as sleep episodes progress - ^ REM occurs in sleep cycle immediately before waking (i.e cycle 5)

• early sleep cycle: REM can only last a few minutes - later in the night - last up to an hour

• singular sleep stage

NREM:

• less active brain than NWC

• physical movement is possible - body may be ‘more active’ - movement tends to v as NREM stages progress

• muscle movement is possible

• dreams can still occur but often are less vivid than REM sleep

• don’t usually recall dreams when woken during NREM sleep

• time in NREM sleep = highest during the first half of a sleep episode

• makes up 75-80% of a sleep cycle

• subdivided into 3 stages

NREM stage 1

• transition from being awake into a light sleep - easily awoken

• experience hypnagogic state - feelings of floating of falling, or hypnic jerk

  • sleeper looses awareness of themselves and their surroundings, but is still aware of faint sounds in the enviro

NREM stage 2

• sleeper still in relatively light sleep

• spend most of time asleep in NREM 2

• sleeper is “truly” asleep - as brain waves are medium frequ. + medium amp.

NREM stage 3

• sleeper in deep stage of sleep

• difficult to wake

• woken during this stage: feel drowsy and disorientated

• sleepwalking and sleep talking = likely

EOG (electro-oculograph)

is a device that detects, amplifies, and records the electrical activity of the muscles responsible for eye movement

• electrodes attached to skin around eyes

• REM: rapid eye movement - high activity

• NREM: low activity

Electromyograph (EMG)

a device that detects, amplifies, and records the electrical activity of the body’s muscles

• electrodes attached to skin above the muscles under investigation

• REM: v activity

• NREM: moderate activity - physiological activity. As NREM sleep stages progress, v movement

Electroencephalograph (EEG)

a device that detects, amplifies and records the electrical activity of the brain

• electrodes are attached to one’s head

• often: ^ freq, v amp. in NWC & v freq. ^ amp. in ASC

• ^ freq, v amp in REM sleep

• ^ freq, v amp in NREM 1 (but v freq. and ^ amp. compared to NWC)

• medium freq. and medium amp. in NREM 2 (light sleep)

• v freq., ^ amp in NREM 3

sleep diaries

a record containing self-reported descriptions from an indiv. about their sleeping periods, including an est. time spent sleeping and judgements they might have about the quality and nature of their sleep

• subjective - qualitative - often extensive in detail + description

• interpreted by a dr or professional - ^ room for error + in accuracy

• info gathered inc.: duration, quality, thoughts + feelings before going to sleep, thoughts + feelings after waking up, behaviours before + after waking up, # of times sleep was disrupted

video monitoring

the use of cameras and audio technologies to record an indiv. as they sleep

• interpretation may be subjective i.e awake vs sleepwalking

• useful for those w/ sleep disorders + used in conjunction w/ physiological measures to ^ validity i.e spike in EMG recording - verify w/ bodily movement in bed

neonatal

• sleep = highest it’ll ever be at ~16 hours!! ~50% REM and 50% NREM

• REM sleep is high bc of rapid brain development

• sleep requirements for Hy functioning: 14-17 hours

• typically sleep avg: 16 - 18 hours

Infancy

• sleep duration V to ~13.5 hours

• REM ~35% & ~65% NREM - still rapid brain development

• sleep requirements for Hy functioning: 12 - 15 hours, typical sleep avg: 13-15

childhood

• sleep duration v to ~11 hours

• NREM ~80%, REM ~20% - pace of brain dev. steadies

• duration of sleep varies due to length of this lifespan stage

• sleep requirements for Hy functioning: 10-14 hours, typical sleep avg: 11 hours

adolescence

• sleep duration decreases ~9 hours

• REM ~20% and NREM ~80%

• experience a biological delayed sleep onset by 1-2 hours - become sleepier later and wake up later

• sleep patterns may change - changes in social factors i.e wake up early for school + social commitments at night.

• prone to delayed circadian phase disorders - biological ‘clocks’ not aligned with the demands of their enviro

• sleep requirements for Hy functioning: 8 - 10 hours

young adulthood

• sleep duration v to ~7.75 hours

• ~20% REM and ~80% NREM

• sleep requirements for Hy functioning: 7 - 9 hours

middle adulthood

• sleep duration remains @ 7-8 hours

• still ~20% REM and 80% NREM

• sleep requirements for Hy functioning: 7-9 hours

old age

• sleep duration decreases to ~6 hours

• still ~20% REM and ~80% NREM

• may experience advanced sleep phase disorder- biological shift forward in their sleep-wake cycle - become sleepier earlier and wake up earlier

• lower levels of sleep may be attributed to ill-health - ^ in prevalence of sleep disorders + v amount of cognitive and physical growth

• sleep requirements for Hy functioning: 7 - 8 hours

frequency

*rate

the number of brain waves that occur per second

amplitude

*height

the intensity and height of brain waves

sleep deprivation

inadequate quantity and/ or quality of sleep

partial sleep deprivation

inadequate sleep either in quantity or quality - the indiv. has had some sleep w/in a period of 24 hours, but the duration or quality of sleep is poor

• based on how much sleep an indiv. needs to feel fully rested

BAC = 0.05%

affective

relates to one’s experience of their emotions

• trouble regulating emotions

• irritability + moodiness

• v ability to cope w/ stress

• v empathy for others

• difficulty judging other ppl’s emotions

• ^ aggression and impatience

behavioural

refers to one’s observable actions

• struggle to control behaviour

• participant more in risk-taking/ impulsive behaviours

• take longer to finish tasks

• have v productive and work efficiency

• experience fatigue/ lack of energy

• slower reaction time

• v motor control

• diminished social functioning

cognitive

a person’s mental processing

• trouble w/ memory

• v alertness

• poor concentration

• impaired decision-making and problem solving skills

• make poorer judgement

• experience a lack of motivation

• v retention of info

• v creativity

full sleep deprivation

when an indiv. has had NO sleep w/in a 24 hour period

BAC = 0.10% - above the legal limit for driving in Aus.

Blood alcohol concentration (BAC)

is the percentage of alcohol in the bloodstream

• Vic: legal limit to drive is under 0.05%

sleep disorders

disturbances to the typical sleeping and waking patterns

• broad + encompass many diff. sleep-related issues

circadian rhythm phase disorders

circadian - 24-hour bodily cycle e.g sleep-wake cycle

a category of sleep disorders characterised by a persistent pattern of sleep disruption due to a misalignment b/w circadian rhythm and the sleep-wake schedule required by a person

treat by: bright light therapy: exposing a person to a safe but intense amount of light for a specific amount of time to reset the sleep-wake cycle - present in the morning (impacts melatonin to be released earlier when dark!)

delayed sleep phase syndrome (DSPS)

a circadian rhythm sleep disorder that is characterised by sleep and waking occurring later than usual.

advanced sleep phase disorder (ASPD)

is a circadian rhythm sleep disorder characterised by an advance in the timing of sleep onset and awakening.

• exposed to bright light therapy at night to reset the cycle

shift work

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

bright light therapy

a method used to adjust a person’s circadian rhythm through exposure to a high-intensity light source

• ensure… appropriate time of the exposure sessions, the right amount (intensity + length) of exposure to light & safe exposure

• DSPS: exposed to light in the morning - SCN promotes wakefulness - sends signals to release cortisol - helping SCN send signals for melatonin release earlier, more appropriate sleep time - promoting sleep

• ASPD: exposed in the evening when feeling sleeping - external cue (same as above!) → melatonin released later → encourage SCN to signal cortisol release later in the morning. i.e instead of 5am → 8am

• shift work: depends on the timing, exposure before beginning of their shift work - promote wakefulness - be alert + awake - promote sleepiness later (when not required to work)

sleep hygiene

the practices and habits that promote an individual’s sleep patterns

zeitgebers impacting sleep

daylight

blue light

temperature

eating & drink patterns

mental wellbeing

an individuals’s psychological state, involving their ability to think, process information, and regulate emotions

daylight

the typical light an indiv. is expose to during the day, and is mostly natural blue light

blue light

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

• natural sources: daylight

• artificial sources: technology

temperature

the degree of external heat in the environment that can influence the quality and quantity of sleep

• should be cool temperature

eating and drinking patterns

what, when and how much food is consumed by an individual

• SCN not largely influenced by the timing of meals - is affected by long-term severe food deprivation