Psychology SAC 3

consciousness, and it on a continuem

• Consciousness

  • Awareness of objects and events in the external world, as well as sensations, mental experiences and our personal existence (internal world) at any given moment.

    • varies on a contiuem of awareness with two extremes - total awareness and complete lack of awareness.

Normal Waking consciousness and characteristics

• State of consciousness experienced when awake, and aware of thoughts, feelings and perceptions from internal/external environment.

• Characteristics:

  • clear perceptions and thoughts

  • aware of personal identity

  • sense of time and place

Altered state of consciousness and characteristics

• Distinctly different from normal waking consciousness, in terms of level of awareness and experience.

• Characteristics:

  • differences in the mental processes of internal/ external stimuli

  • self and emotional awareness, perception of time and place may change

  • self control may weaken

Naturally vs. induced altered states of consciousness

• Naturally

  • occur in the course of everyday activities, without the need of an aid.

  • etc. dreaming, sleep and daydreaming

• Induced

  • Intentionally achieved by the use of an aid.

  • etc. hypnosis, meditation, use of substances

Why is consciousness considered a psychological construct

• As it is describes psychological activities that are believed to exist however cannot be directly observed/measured.

• consciousness can be measured by making inferences on:

  • Information provided by individual (ect. self reports)

  • behaviours demonstrated

  • physiological measures (etc. EEG)

What is sleep and characteristics

• A reversible, behavioural state of perceptual disengagement from unresponsiveness to the environment.

  • sleeper has limited/ no awareness of external environment and is unlikely to respond

  • can be woken with a strong enough stimulus.

Non- REM (NREM) non rapid eye movement sleep

• Total 75-80% in NREM

• Rejuvenates body

• NREM1

  • low levels of bodily arousal yet aware of some external stimuli. Light sleep that lasts 1-8 minutes, 4-5% of total sleep time.

• NREM2

  • Individual truly asleep, can still be woken by external stimuli. Light sleep that lasts 10-25 minutes, 45-55% of total sleep time.

• NREM3

  • Individual deeply asleep, predominant at start of sleep episode. Sleep walking/talking occurs in this stage. Deep sleep that lasts 10-40 minutes, 10-20% of total sleep time.

REM - rapid eye movement sleep

• Total 20- 25% of total sleep time spent in REM

• Rejuvenates brain

  • Body is ‘paralysed’, as the individual has a complete loss of muscle tone

  • Brain activity is the same as if conscious (beta waves)

  • Increases in time as sleep episode progresses, ranging from 1-5 minutes up until 20-25 minutes.

Sleep episode/cycle

• Sleep episode - full duration of time spent asleep.

  • made up of multiple repeated cycles of REM and NREM called sleep cycles.

• Sleep cycle - approximately 90 minutes period

  • repeats during a sleep episode, as individual progresses through stages of REM and NREM.

Objective ways of measuring consciousness

• Electroencephalograph (EEG)

  • Detects, amplifies, and records electrical activity of the brain.

  • data records frequency (how many waves occur per second) and amplitude (high and low waves go) brain waves Beta, Alpha, Theta, Delta.

• Electro-oculogram (EOG)

  • detects, amplifies and records the electrical activity of muscles around the eyes.

• Electromyography (EMG)

  • detects, amplifies and records electrical activity of the muscles within the body

Subjective ways of measuring consciousness

• Sleep diaries - self reported descriptions of an individual’s sleep periods, including durations, quality, disruptions and behaviours of sleep.

  • may not be accurate, and a professional analysing sleep may interpret data incorrectly.

• Video monitoring - camera and audio recordings of an individual’s sleep behaviours, helping to identify patterns (etc. movement, vocalisations)

  • can be used in conjunction with objective measures

  • cause of observed behaviours may be unclear/ data misinterpreted.

Biological rhythms

• Recurrent changes in bodily functions/ activities that repeat themselves through time in the same order.

  • biological rhythms maintained and controlled by internal mechanisms - biological clock

  • however external environment can influence biological rhythms.

Circadian rhythms

• Involves changes in bodily functions/ activities that occur as apart of a cycle of approximately 24 hours.

  • etc. sleep wake cycle, daily fluctuations in body temp and release of hormones such as melatonin.

  • sleep wake cycle, involves both biological and external cues that governs when individuals feel awake/sleepy.

  • sleep wake rhythms follow biological clock and sync with environmental photoperiod (light/dark) or else produces problems.

Ultradian rhythms

• Involves changes in bodily functions/ activities that occur as apart of a cycle shorter than 24 hours.

  • etc. respiration, heartbeat, sleep episodes/ cycles

  • sleep cycles considered ultradian as it occurs as a sequence of different states and stages lasting approximately 90 minutes.

Melatonin and its release

• 1- Changes in light levels detected by eyes, transmitted via optic nerve to occipital lobe.

• 2- suprachiasmatic nucleus (SCN) within hypothalamus regulates sleep wake cycles, and receives cues from both internal and external (light) sources.

• 3- suprachiasmatic nucleus activates the pineal gland, triggering release of melatonin.

  • Melatonin = hormone (works via blood) that promotes calmness, therefore sleep.

    • peak melatonin production between 2am-4am.

Sleep across the lifespan, duration, sleep onset and proportion of REM and NREM

• Duration - decreases across the lifespan

• Sleep onset (time taken to fall asleep) increases

  • natural physiological changes (reduction in circadian rhythms etc. sleep wake cycle, and melatonin)

  • environmental/lifestyle factors

  • prevalence of sleep disorders

• REM decreases, as NREM increases

  • decrease in brain’s ability to generate deep sleep

  • decrease in the need for rapid brain development and neural connections as a result of brain maturation

Sleep deprivation - Total and partial

• Sleep deprivation - describes a state caused by inadequate quality/ quantity of sleep.

  • Total = complete lack of sleep within 24 hour period.

  • Partial = Individual sleeps for some duration of 24 hour period:

    • duration either too short

    • quality of sleep is poor

sleep deprivation impacts on affective functioning

• Changes in emotions/ emotional responses that arise from sleep deprivation.

  • poor emotional regulation (amplified emotional responses/ out of proportion)

  • irritability/ moodiness

  • reduced empathy towards others

  • reduced ability to cope with stress

Sleep deprivation impacts on behavioural functioning

• Changes in actions and the ability to control them, arising from sleep deprivation.

  • sleep inertia (sense of disorientation after waking)

  • lack of energy/ fatigue

  • reduced motor control/ reaction time

  • microsleeps

Sleep deprivation impacts on cognitive functioning

• Changes in mental processes that arise from sleep deprivation.

  • tendency to lose situational awareness

  • impaired memory/ learning processes

  • lapses in attention

  • reduced concentration

Sleep deprivation vs. BAC

• BAC = a measure of how much alcohol is in a person’s bloodstream.

  • BAC of 0.05 = equivalent to 17 hours of sleep deprivation (partial)

  • BAC of 0.10 = equivalent to 24 hours of sleep deprivation (total)

effects of sleep deprivation compared to BAC

• Effective = impacts emotional state, e.g extreme moods

  • sleep deprivation = irritable/ sensitive moods

  • BAC = happy/ excited, angry, sad

• Cognitive

  • slowed mental processes = reduced speed in processing/ understanding info

  • cognitive distortions = greater difficulty making sense of world

• Behavioural

  • slowed reaction time/ decision making

Circadian sleep phase disorders

• Describes sleep disorders that disturb the typical regulation of the circadian rhythm of sleep

  • leading to changes in the sleep wake cycle.

Delayed sleep phase disorder (DSPD), causes

• Circadian rhythm sleep disorder in which sleeping and waking occur later than usual.

  • caused by misalignment between external (light) and internal cues that regulate sleep wake cycle/ body.

    • external cues received at appropriate time, internal cues not, leading to later secretion of melatonin.

• Causes: lifestyle factors, shift work, poor sleep habits, jetlag, adolescence

Advanced sleep phase disorder (ASPD)

• Circadian rhythm sleep disorder in which sleep and waking occur earlier than usual.

  • caused by misalignment between external (light) and internal cues that regulates the sleep wake cycle/ body.

    • external cues received at appropriate time, internal cues not, leading to melatonin production occurring earlier.

• Causes: lifestyle factors, genetics, jet lag, old age

Shift work

• Occupation that involves working at unusual hours, such as working overnight to meet a 24/7 society.

  • Impacts sleep wake cycle as circadian rhythm is constantly changing and adapting to environment, leading to difficulties initiating sleep and waking while adjusting to/from shifts.

  • contributes to development of sleep disorders:

    • Insomnia, fragmented sleep, circadian rhythm phase disorder, quality/ quantity of sleep impacted.

Bright therapy

• Involves using a high intensity light source to adjust one’s circadian rhythm.

  • Bright light detected by suprachiasmatic nucleus as external cue

  • signals for cortisol release, suppressing melatonin

  • lack of melatonin promotes wakefulness

Successful treatment factors for bright light therapy

• Appropriate timing of exposure sessions

  • sessions should be conducted on consecutive days

• Right amount of light

  • intensity of light and exposure periods should gradually increase (15 min - couple of hours)

• safe exposure

DSPD = exposure in morning, ASPD = exposure in afternoon, SHIFT WORK = exposure typically before shift (depends on details/ timing of work).

Sleep hygiene/ correlation to mental health and wellbeing/ Zeitgebers

• sleep hygiene = practises and habits that promote your sleep pattern.

  • Sleep hygiene influences mental health and wellbeing (psychological state)

    • bi- directional link between poor sleep and mental illness - as they influence one another.

• Zeitgebers = external cues that influence circadian rhythm.

Light as Zeitgebers

• Light = Influences sleep wake cycle, promoting wakefulness/ reducing sleepiness

  -inhibiting release of melatonin from pineal glands by signalling suprachiasmatic nucleus.

  • Natural light = natural light from environment, etc. sunlight

  • Blue light = artificial source of light that acts as natural light at times there is none, etc. technology.

Temperature as zeitgeber

• Temperature = external heat in the environment that can influence quality and quantity of sleep.

  • when sleeping body temperature drops.

  • Research suggests a cool environment promotes sleep, specifically temperatures of 18.3 degrees.

Eating and drinking as a zeitgeber

• Eating too much/ too close to sleep = reduces ability to initiate sleep, body focused on digestion, impairing sleep pattern.

• Eating too little before sleep = negatively reduces quality and quantity of sleep.

  • caffeine = stimulant - stimulates CNS (delay sleep onset)

  • alcohol = depressant - slows CNS

  • spicy food = increases body temperature (delay sleep onset)

  • high sugar/ fat food = increases wakefulness (reduce sleep quality/quantity)