VCE Psychology Unit 4 AOS 1 - How does sleep affect mental processes and behaviour?

consciousness

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

is a psychological construct

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 individual is awake and aware

altered state of consciousness (ASC)

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

naturally occurring ASC

a type of ASC that occurs without intervention

e.g. sleep, daydreaming

induced ASC

a type of ASC that occurs due to a purposeful action or aid

e.g. meditation, hypnosis, influence of drugs/alcohol

consciousness continuum

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

sleep

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

is a psychological construct

NREM sleep

a type of sleep characterised by a lack of rapid eye movement and is subdivided into three different stages

REM sleep

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

sleep episode

the full duration of time spent asleep

sleep cycle

an approximately 90-minute-period that repeats during a sleep episode in which an individual progresses through stages of REM and NREM sleep

NREM Stage 1

a transitional phase between wakefulness and sleep

considered to be light sleep and is signified by the experience of the hypnagogic state, where people experience feelings of floating/falling or a sudden hypnic jerk.

the sleeper loses awareness of themselves and their surroundings but is still aware of faint sounds in the environment

NREM Stage 2

relatively light sleep

individuals spend the majority of their time asleep in NREM stage 2

considered to be truly asleep due to the brain waves in this stage

NREM Stage 3

considered to be deep sleep, and a person is difficult to wake and is likely to feel disoriented and drowsy if they are woken

most likely for sleep-waking and talking to occur in this stage.

REM characteristics

highly active brain and less active body

virtually paralysed

sleepers can be woken fairly easily

vivid dreaming

20-25% of a sleep episode for most

amount increases as a sleep episode progresses

NREM characteristics

less active brain than NWC

physical movement is possible but tends to decrease as stages progress

non-vivid dreams that are unlikely to be recalled

becomes shorter with each sleep cycle

makes up 75-80% of a sleep episode

Electroencephalograph (EEG)

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

detects the electrical impulses emitted by neurons when they communicate

Electromyography (EMG)

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

Electro-oculography (EOG)

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

sleep diaries

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

video monitoring

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

objective physiological measures

EMG, EOG, and ECG

they provide reliable, unbiased, quantitative data that can indicate someone's state of consciousness.

subjective measures

sleep diaries and video monitoring

information is provided by an individual and is related to their personal experiences.

high frequency low amplitude

a person is fairly alert

low frequency high amplitude

a person has lower levels of alertness

amplitude

the intensity and height of brain waves

frequency

the number of brain waves that occur per second

beta

brain waves that have high frequency and low amplitude

alpha

brain waves that have high frequency (lower than beta) and low amplitude (higher than beta)

theta

brain waves that have medium frequency and medium-high amplitude

delta

brain waves that have low frequency and high amplitude