VCE Psychology Unit 4 Aos 1

Sleep

Brain wave

An electrical impulse in the brain

Brain wave pattern

Patterns of electrical activity occurring in the brain

Types of brain wave patterns (in order)

• Beta

• Alpha

• Theta

• Delta

Beta brain wave pattern

Associated with alertness and intensive mental activity during normal waking consciousness

• High frequency, low amplitude

• Also present during REM sleep dreams

Alpha brain wave pattern

Associated with a relaxed, calm, internally focused wakeful state of consciousness, especially if eyes are closed

* Medium to high frequency, low amplitude

Theta brain wave pattern

Associated with drowsiness, falling asleep and creative activities

* Medium frequency, mix of high and low amplitude

Delta brain wave pattern

Associated with deep, dreamless sleep or unconsciousness

* Low frequency, high amplitude

Consciousness

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

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The awareness of our own thoughts, feelings and perceptions (internal events) and our surroundings (external stimuli) at any given moment. (ppt)

What 4 things are conscious experience

• Subjective - Your personal understanding of your internal and external world

• Selective - You can choose to pay attention to certain things and ignore others

• Continuous - Your consciousness is never empty

• Changing - New information is continually coming into your awareness, especially while awake

States of consciousness

The different states of awareness that we experience

Examples…

• Normal waking consciousness

• Altered state of consciousness

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 (ASC)

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

Differences between NWC and ASC

ASC

• More the extremes of emotions and sensations

• Self control may weaken

• Reduced time orientation

• Lower level of responsiveness to the environment

• Lower level of awareness

• Poorer memory

Naturally occurring state

Altered states of consciousness that are naturally occurring in the course of everyday activities without the need for any aid

Examples…

• Sleep

• Dreaming

• Daydreaming

Induced state of consciousness

A temporary change in one’s normal mental state without being considered unconscious

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

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They cannot be objectively measured or observed through the collection of data and are inferred from information gathered from the individual or behaviour or from physiological measures.

Distinguishing factors of sleep

• Reversibility

• Perceptual disengagement

• Unresponsiveness to the environment

Sleep-wake cycle/pattern

The 24 hour daily sleep pattern which consists of approximately 16 hours of daytime wakefulness and 8 hours of night-time sleep

* Is endogenous

Endogenous

Originating within an organism

Exogenous

Originating outside an organism

Sleep episode

An interval of sleep that may be voluntary or involuntary

Biological rhythm

Naturally occurring cyclic changes to bodily functions or activities (physiological, psychological, behavioural) that repeat themselves through time in the same order.

Examples…

• Circadian rhythm

• Ultradian rhythm

Circadian rhythm

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

Ultradian rhythm

A biological rhythm involving physiological, psychological or behavioural changes that occur as part of a cycle shorter than 24 hours (typically 90 minute periods)

Stages of ultradian cycles

• NREM Stage 1

• NREM Stage 2

• NREM Stage 3

• REM

NREM sleep

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

* Physiological restoration

NREM stage

Sleep that occurs first and includes three stages

NREM 1

• Approx 5 minutes

• Transition between wakefulness and sleep

• Very light sleep

• Low arousal threshold

• Alpha waves → theta waves

• Decrease heart rate, breathing, body temperature, muscle tension

• Hypnic jerks

• Vivid images and flashes

• Slow, gentle, rolling eye movements

Hypnic jerks

Involuntary muscle twitches that make us jolt

NREM 2

• First cycle = 10-25 minutes

• Higher arousal threshold than NREM 1

• Theta brainwaves

• Eyes stop rolling

• Muscles more relaxed

• Breathing and heart rate continue to decrease

• Sleep spindles

• K-complexes

Sleep spindles

Short bursts of rapid brainwave activity

K-complex

A single sudden high amplitude wave, which occurs about once a minute

NREM 3

• First cycle = 30 minutes

• Highest arousal threshold

• Sleep inertia if awoken

• Theta waves → delta waves

• No eye movement

• Little-no muscle activity

• Heart rate and breathing most regular/slowest

• Lowest temperature

REM sleep

Rapid eye movement sleep

• First cycle = 5 minutes

• Higher arousal

• Beta-like sawtooth waves

• Dream sleep

• Helps to consolidate memories (psychological restoration)

• No muscle tension - muscle atonia

• Increase and fluctuations in heart rate, breathing, temperature and blood pressure

Light sleep

The transitional stage between waking and sleeping

Deep sleep

A period of sleep when the heart rate and breathing slow to their lowest levels, the muscles are completely relaxed with barely any body movement and no eye movements

Arousal threshold

An individual’s sensitivity to being woken from a sleep state

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

Biological clock

Innate timing that regulates one or more biological rhythms

Body clock

A circadian rhythm controlled by an area of the hypothalamus called the suprachiasmatic nucleus.

• It regulates the timing and activity of the person’s sleep–wake cycle.

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)

Light and the SCN

•Less light → SCN signals pineal gland to produce & secrete melatonin → makes us drowsy & induces sleepiness

Melatonin

A hormone secreted by the pineal gland in response to the amount of light in the environment that induces drowsiness and sleep.

• Influences alertness and drowsiness and timing of the sleep-wake cycle

• A higher melatonin level is associated with greater drowsiness and vice versa

Hypnogram

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

• Displays how NREM and REM sleep alternate

• 4-5 continuous cycles per night

• Each cycle is approximately 90-120 minutes

• NREM 3 earlier in the night

• REM increases as the night goes on

Electroencephalography (EEG)

**DETECTS, AMPLIFIES & RECORDS** **ELECTRICAL** activity of the **BRAIN** in the form of brainwaves.

* A method of studying brain wave patterns by recording the electrical activity of the brain

Frequency

The number of brainwaves/second.

* Indicates speed of the brainwaves or how much activity is occurring every second (higher frequency = faster brainwaves)

Amplitude

The height of the peaks and troughs of the graph.

* Indicates the intensity or strength of the brainwave or how many brainwaves are firing at the same time

EEG Benefits

EEG recordings help:

• Determine abnormal activity

• Monitor changes with states of consciousness

• Identify different states of consciousness

• Assist with the diagnosis & study of brain-related medical conditions

EEG limitations

• Only good at measuring neural activity on the cortex

• Does not provide detailed information about which brain structures are activated

• Strength of electrical activity at its source is reduced after having to travel through the skull

Electromyography (EMG)

DETECTS, AMPLIFIES & RECORDS ELECTRICAL activity of MUSCLES.

• A method of studying the electrical activity of muscles during sleep

• Indicates changes in muscle activity and tone

• Higher the muscle tone/activity, the more alert

Electro-oculargraphy (EOG)

DETECTS, AMPLIFIES & RECORDS ELECTRICAL activity in eye muscles that control eye movement.

• A method of measuring eye movements or eye positions during sleep

• Measures voltage changes as the eyes move and rotate

Benefits of using physiological responses

• Quantitative

• They are the most objective & reliable means of identifying different states of consciousness

• The data is consistent & stable

• The data can be recorded & interpreted consistently between researchers and at different times

Limitations of using physiological responses

• Limited in its ability to identify the participant’s private and personal conscious experience

• Changes are observed but the actual conscious experience changes come from asking the participant (i.e. thoughts, feelings and perceptions)

• Physiological changes may be the result of something else (eg have a fever)

Sleep diary

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

Sleep diary benefits

• As they include qualitative data the information gathered from them can often be more specific and detailed

• May include both qualitative and quantitative data

Sleep diary limitations

As it is a subjective measure, its data can often be…

• Biased due to need for interpretation

• Vary from person to person

… therefore not always entirely accurate

Video monitoring

One or more video cameras to monitor and record externally observable physiological responses throughout a sleep episode

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

Chronic sleep deprivation

Not having enough sleep over an extended period of time

• Associated with severe psychological + physiological conditions, such as…

• Depression

• Heart disease

• Diabetes

• Obesity

• Some forms of cancer

• Anxiety disorders

• Cardiovascular disease

• Mood disorders

• Immune deficiencies (including cancer)

Sleep quantity

Refers to the amount of sleep a person gets

Sleep quality

Refers to how well a person feels they have slept

Sleep disturbance

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

Sleep debt

The accumulated amount of sleep loss due to insufficient sleep

• The difference between the amount of sleep that is needed to function at an optimal level and the amount a person actually gets

• Only some needs to be recovered

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

Sleep-wake cycle shift

A change (advancement or delay) in the timing of the major sleep episode

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

A sleep disorder that cannot be attributed to another condition, such as…

• Another sleep disorder

• A mental disorder

• Medical problem

• Substance use

Secondary sleep disorder

A prominent sleep problem that results from another condition or substance use

Circadian rhythm sleep disorder

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

Examples…

• Delayed Sleep Phase Syndrome (DSPS)

• Advanced Sleep Phase Disorder (ASPD)

• Shift Work Disorder

Delayed Sleep Phase Syndrome (DSPS)

A circadian rhythm sleep disorder/condition in which the major sleep episode is delayed in relation to the desired sleep time or what is considered a conventional time

• Pushed forward by 2 or more hours

• Usually cannot fall asleep earlier due to shifted circadian rhythm

Predisposing risk factors for DSPS

• Adolescence

• Increased sensitivity to light

DSPS symptoms

• Sleep-onset insomnia

• Difficulty awakening at the desired/necessary time

• Excessive sleepiness

Symptoms must be experienced for more than 3 months for diagnosis

Sleep-onset insomnia

A sleep disorder that typically involves persistent difficulty initiating sleep

(NOTE: Usually sleeps through the night once sleep starts)

When do sleeping patterns shift back?

• 19.5 years for females

• 21 years for males

Advanced Sleep Phase Disorder (ASPD)

A 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

* Pushed backwards by 2 or more hours

Shift work disorder

A 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

Fixed shift work schedule

When employees work the same shift on a regular, ongoing basis

Rotating shift work schedule

When employees change shifts every so often to work a mix of day and/or afternoon and/or night shifts

Shift Work Disorder symptoms

• Insomnia when a person is trying to go to sleep

• Excessive sleepiness when a person needs to be awake and alert

• Associated with a reduction in total sleep time too

Diagnosis depends on the severity of the symptoms and the level of distress experienced by the individual

Shift Work strategies

• Consistent night shift is best → good to spend longer in one shift rotation before changing

• If rotation is required → should shift forwar

(Best chances to adjust)

• Dark, quiet bedroom

• Maintain a sleep schedule of daytime sleep, even on days off

• Wear sunglasses on the way home from work

Affective functioning

The attitude or emotion elicited by a stimulus (such as sleep deprivation)

Affective disturbances…

• Mood disturbances - amplified emotional responses

• Irritability

• Feelings of sadness

• Increased aggression

Emotional reactivity

The tendency to experience frequent and intense emotional arousal

Behavioural functioning

The effects on behaviour elicited by a stimulus (such as sleep deprivation)

Behavioural difficulties…

• Sleep inertia

• Slower reaction time

• Reduced productivity + work efficiency

• Increased clumsiness

• Increased risk-taking behaviour

Physiological effects…

• Lower energy levels

• Shaking

• Droopy eyelids

• Increased pain sensitivity

• Headaches

Cognitive functioning

The effects on cognitive processes elicited by a stimulus (such as sleep deprivation)

Cognitive difficulties…

• Difficulty paying attention + concentrating

• Difficulty thinking clearly, making decisions + problem solving

• Impaired learning + memory processes

REM rebound

After being deprived of REM sleep we experience a significantly larger amount of time in REM sleep

Microsleep

A very short period (i.e. between 3 and 15 seconds) of involuntary sleep

* Often occurs to help prevent/reduce sleep deprivation

Who investigated the relationship between sleep deprivation, alcohol consumption and impaired performance?

Australian psychologist Drew Dawson and neurologist Kathryn Reid (1997)

Dawson & reid (1997)

• 40 participants

• Counterbalanced within subjects design

Conditions:

1. kept wake for 28 hours

2. consumed 15 grams of alcohol every 30 minutes until BAC reached 0.10%

• Participants assessed on ‘cognitive psychomotor performance’ at half-hourly intervals

Blood-alcohol concentration (BAC)

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

Effects of sleep deprivation vs BAC

• 17 hours of sustained wakefulness = BAC of 0.05%

• 24 hours of sustained wakefulness = BAC of 0.10%

BAC Affective

• Poorer emotional regulation

• Increased irritability

• Emotional outbursts

BAC Cognitive

• Impaired concentration

• Lowered attention

• Poorer decision making

• Decreased problem-solving ability

Bright light therapy

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

• Sits 30cm from box

• 15 minutes - 2 hours

• 1-2 times a day

Bright light therapy side effects

(Mostly only at the beginning)

• Eye irritations

• Dry skin

• Headaches

• Nausea

3 important variables (bright light therapy)

• At the right time of day

• At the right intensity

• For the right amount of time

When to administer light therapy

• DSPS → In the early morning hours

• ASPD → In the early evening

• Shift Work Disorder → In the evening as they go off to work