sleeping and dreaming

IGCSE psychology

REM sleep definition + other facts

• part of the sleep cycle with rapid eye movements caused by eyes moving a lot behind the eyelids during dreaming

• every night we spend about 2h dreaming

• stimulates learning

• increases proteins

physical characteristics of REM

• rapid, shallow and irregular breathing

• muscles paralysed

• rapid eye movement

• heart rate + blood pressure increases

sensory blockade + movement inhibition

• sensory blockade - during REM sleep incoming information from the senses is blocked

• movement inhibition - signals at the pons (at the base of the brain) shuts down neurons in the spinal cord preventing movement.

alpha vs theta brainwaves

• alpha - restful

• theta - characterise a period between sleep and wake

stage 1 of sleep

• sleep onset

• light sleep → easily woken

• muscles are less active, slow eye movement, sudden twitches can occur

• alpha + theta brain waves

stage 2 of sleep

• late night stage

• light sleep → sleep

• slower mainly theta brain waves

• no eye movement

• bursts of brain activity

• body temperature drops

• heart rate slows down

stage 3 of sleep

• deep sleep

• slow delta brain waves + some faster ones

• between light and deep sleep

• very hard to wake up during stages 3 + 4

stage 4 of sleep

• deep sleep

• almost all waves are slow delta waves

• no eye movements

• when woken up you can feel disoriented

• children can experience sleep walking/night terrors when in deep sleep

sleep in different ages

• adults - 7-8h, teens - 9h

• over 65y deep sleep stops due to age or medication

• infants - 50% of sleep = REM

• normal - 20% of sleep = REM

sleep deprivation

• people fall asleep during the day or immediately when they go into bed

• person will not function as well at a high level (can affect work + driving)

• Animal studies show that sleep is needed for survival. (e.g ,rats can die after about 3 weeks of no sleep.)

• little sleep → brain chemistry affected,

• sleep helps neurons repair themselves.

• Deep sleep can help avoid the breakdown of proteins.

sleep cycle

• 1 cycle - 90min

• about 5 cycles in 1 night

• 1st cycle → little REM sleep + a lot of deep sleep

• 5th cycle → a lot of REM sleep + less deep sleep

circadian vs ultradian rhythms definition

• circadian - human body rhythms that have a daily (24hour) cycle, (e.g sleep– wake cycle)

• ultradian - rhythms that occur in a period of less than 24 hours (e.g sleep cycle)

Hormones definition

chemical messengers taking messages through the bloodstream.

Melatonin definition

a hormone involved in setting circadian rhythms, including the sleep–wake cycle and blood pressure.

Entrainment definition

• when biological rhythms are matched to their environmental triggers

• (e.g circadian rhythms being set in response to external (light) cues. )

zeitgebers definition

external cues that synchronise our biological rhythms (e.g, to a 24hour clock.)

exogenous vs endogenous zeitgebers definition

• exogenous - external cues in the environment that affect our biological clock.

• endogenous - internal pacemakers; our biological clock

sleep wake cycle definition

a circadian rhythm generally triggered by the day-night cycle

pineal glands definition

• a small endocrine gland that produces melatonin.

• An endocrine gland produces a hormone that is secreted into the bloodstream

internal influences on sleep / endogenous zeitgebers

• suprachiasmatic nuclei

• internal body clock - keeps biological rhythms synchronised

• pineal gland - melatonin which is triggered by darkness signals the need for sleep

• too much adrenaline due to active day/stress → difficulty falling asleep due to a lot of cortisol released by the ACTH (hormone)

• more of ACTH is found in people with insomnia

The suprachiasmatic nuclei

• a type of biological clock that is able to keep our circadian rhythms close to a 24-hour cycle(even without the help of external cues)

• Two small,paired nuclei that are found in the hypothalamus

• contains about 10,000 neurons

strengths of internal influences

• evidence from animal research shows that SCN plays a role in setting a biological clock ( e.g when SCN when removed from hamsters their biological rhythms stopped)

• evidence from human research that circadian rhythms are controlled by internal factors (e.g bodily rhythm of blind man → 25h)

• real world applications → melatonin supplements can be given to help with insomnia

weaknesses of internal influences

• difficult to generalise animal research. (humans have more complex brains)

• animal research was unethical

• some blind people are able to perceive light → cannot draw conclusions

• drugs can affect people differently

external influences on sleep / exogenous

• zeitgebers - light enters cells in retina to let us know when it is day

• entrainment - We use stimuli around us to coordinate our biological clocks

• biological clock is set each day

human sleep-wake cycle

• circadian rhythm

• Light enters retina → stimulates SCN to produce an inhibiting factor (probably a protein) → no melatonin production → keeps you alert + awake

• In darkness melatonin is produced which reduces arousal

Research evidence supporting exogenous control through Zeitgebers - Miles et al.

• man blind from birth had a circadian rhythm of 24.9 hours.

• had to use stimulants and sedatives to adjust his sleep-waking cycle to 24 hours.

• shows that light is the main exogenous factor, as it reduces the natural 25 hour rhythm to 24 hours

Research evidence supporting exogenous control through Zeitgebers - Luce and Segal Arctic Circle study

• people in arctic sleep 7h despite the fact that during the summer the sun never sets

• shows that light is not the only zeitgeber, social customs + psychological factors play a role too

strengths of external influences on sleep / exogenous

• practical applications - (e.g shift workers can darken their bedrooms during the day)

• evidence - Mistlberger and Skene agreed that light is the main way bodily rhythms are synchronised.

weaknesses of external influences on sleep / exogenous

• some people are morning larks/night owls → genetic

• research shows that Circadian rhythms were disrupted by 3 hours when light was shone on the back of the knees.

• sleep deprivation studies lack validity - (e.g artificial light)

Insomnia

• problems with sleeping at night that cause difficulties during the day

• affects 1 in 3 people

• often found in older people

acute vs chronic insomnia

• acute - a brief period of problems with sleep

• chronic - difficulty with sleep occurs 3 or more nights a week for at least 3 months

symptoms of insomnia

• difficulty falling asleep

• waking up a lot during the night

• frequently lying awake during the night

• not feeling refreshed when waking

• finding it hard to fall asleep in the day when tired

• feeling irritable or unable to concentrate

why does insomnia occur

• life styles that include frequent flying(jet lag) or working night shifts

• health conditions - e.g depression/heart problems

• Medication, food and drink - anything that affects hormones and/or neurotransmitters e.g caffeine, diet pills, etc.

narcolepsy

• inability to control sleeping and waking,

• affects males and females equally

• 1 in every 2000 people

• 70% of people with narcolepsy experience cataplexy

symptoms of narcolepsy

• Excessive daytime sleepiness (EDS) - can fall into uncontrollable sleep at any time

• Hallucinations + vivid dreams

hallucinations vs vivid dreams

• hallucinations - experiencing something that is not there e.g feeling of danger

• vivid dreams - separating dreams from reality is difficult

cataplexy

• experience loss of muscle power + tone due to strong emotions

• sleep paralysis + abnormal REM - sleep paralysis can happen at anytime

why does narcolepsy happen

• brain chemicals : cells in the hypothalamus that produce hypocretin (chemical in our brain that keeps us awake) are damaged or missing.

• Genes : 10% of people with narcolepsy have family members who also have it. - variations in chromosome 6

• Stress/trauma - Wayne Barker found a link between situational stress and narcolepsy

• evolution - muscle paralysis can be seen as a survival characteristic as it might be advantageous for an animal to be very still in order to stay alive.

unconscious mind definition

an inaccessible part of the mind that affects behaviour and feelings

importance of the unconscious - Freud

• dreams involve symbols that mean something →( need to be analysed by psychoanalyst)

• conscious - what we are already aware of

• preconscious - what we can make ourselves aware of with some thinking

• unconscious - 90% of thinking, contains repressed thoughts that challenge us (e.g sexual wishes)

Id, ego and Superego

• Id - ‘I want’

• ego - balances demands of Id and superego (e.g through repression/not remembering)

• Superego - ‘you can’t have’

manifest vs latent content

• manifest - the story the dreamer tells of what happens in a dream (things you see) → where psychoanalyst looks for symbols

• latent - the deeper meaning behind what it is said the dream to be about

Dreamwork definition

• the transformation of unconscious thoughts into dream content

• refers to the way the mind keeps unconscious thoughts hidden during dreaming (to protect the individual and keep them asleep)

condensation, displacement, secondary elaboration - dream work

• condensation - many ideas appear as one in a dream. therefore the one idea needs to be unpicked as the separate parts can be important.

• displacement - in a dream, something unimportant seems important. (e.g a new person is introduced to take the attention away from something threatening)

• elaboration - using muddled ideas from dreamwork to build a whole story. the mind will add bits to the dream in order for it to make sense → gets in the way of analysing latent content

symbols

• symbols have different meanings for different people

• the psychoanalyst need to know the patients past in order to be able to analyse their dream

strengths of Freud’s theory of dreaming

• qualitative + detailed data focused on individuals - high validity.

• any interpretation had to be accepted by the patient - validity

• found a way of studying the unconscious, which cannot be easily be studied. (got the idea from his patients having recurring dreams)

• evidence that dreams ‘guard sleep’ - Guénolé et al. found that when people slept where there was noise they dream more → dreams kept them asleep

weaknesses of Freuds theory of dreaming

• data is interpreted by analyst - lacks validity

• Freud’s ideas about dreaming cannot be easily tested - cannot be shown to be true/false

• concepts (e.g unconscious) cannot be measured objectively - un scientific

• case studies were used (e.g little hans) - each analysis was unique to the individual - cannot be generalised

psychosexual stages definition

Freuds (1905) theory of child development (oral, anal, phallic, latent and genital stages)

phallic stage + oedipus complex - Freuds theory definition

• phallic stage - the 3rd stage in Freud’s theory of child development during which the Oedipus complex is worked through.

• oedipus complex - (part of phallic stage) a boy has unconscious feelings for his mother and hates his father, who he sees as a rival and fears will castrate him

Aims of Little Hans

• To help the individual (little Hans)

• To build evidence for his theory of how children develop

Sample of Little Hans

• one child - case study

• 3-5 years old

Procedure of Little Hans

• reports of Little Hans behaviour began in 1906 and were recorded by his father

• during this time Hans developed a phobia for horses

• Hans dreams were recorded from 1907 onwards

• Freud analysed his dreams, reports and what he said using psychoanalysis to find out what was in his unconscious that caused his phobia in order to cure it.

Hans phobia of horses results

• Han’s once saw a horse carrying loaded carts fall down and die on a street

• Han’s particularly did not like horses with black bits around their mouth which Freud thought to represent his father’s moustache.

• Horse = symbol for father

• Fear or horses → unconscious fear that father would castrate him (because Hans wanted his mother). - Oedipus complex

• Han’s phobia was helped with imagination + roleplay → father was seen as grandfather.

Hans early dream

• at 5y Hans had woke up from a dream crying that his mother was gone → Freud said this showed anxiety that his mother would leave

• Oedipus complex → fear that Hans father would take his mother away

• Unconscious wishes (sexually posses mother) are repressed and leaked out in the dream

hans giraffe dream

• one big giraffe and one small crumpled one

• The big giraffe shouted because Han’s took the little giraffe away

• Freud + father thought that giraffe was a symbol for penis but Hans denied this

• Freud linked this to the fact that Hans likes to get in bed with his parents in the morning which his father did not like

• Big graffe → father

• crumpled → mother

Little Hans conclusion

• Freud used evidence form Little Hans case study to support his theory that children develop in a series of psychosexual stages

• the case study was also used as evidence was also used to support Oedipus complex in small boys

• Hans seemed to fear his father and wanted him to go away

• wanted to keep his mother away from his father. And keep her all to himself

Strengths of little Hans case study

• Holistic - Freud gathered a lot of in depth information about the little boy from parents and the boy → richness + validity to data

• Qualitative data

• scientific - carefully documented + kept a reflective account

Weaknesses of Little hans case study

• Little Han’s parents knew about Freud’s ideas - a lot of info came from Han’s father → only passed information that suited the oedipus complex. → Bias

• case study → unique to little Hans → cannot be generalised to a universal theory

• There is a learning explanation for Han’s phobia

Activation Synthesis theory description

• Biological theory of dreaming

• Brain is active during REM

Activation vs synthesis definitions

• Activation - During REM sleep neurons in the brain are activated by random impulses which generate random thoughts/memories

• Synthesis - The brain tries to make sense of this ‘nonsense’ random memories by putting them together and making a sequence/story

Strengths of activation synthesis theory

• evidence - People observed in lab all show REM but muscles are paralyzed → dreams occur from random neurons firing

• McCarley and Hobson used cats to find which parts of the brain are active during REM. - found activity in pons

• by using animals it allows researchers to study brain activity that wouldn’t be able to be studied in any other way

• model is still being improved → lead to AIM model

weaknesses of activation synthesis theory

• animals are different from humans → studies with animals cannot be generalised to human functioning

• people often link dreams with things that happened recently → random neurons firing have meaning

• Rittenhouse et al. found that 66 out of 200 dreams made logical sense - evidence against theory

Siffre Aims

• To investigate the effects of living underground in a cave with no external cues on the sleep-wake cycle

• Study was sponsored by NASA as they wanted to see the possible effects on their astronauts of being isolated from external cues while in space

Procedure Siffre

• Sample - 1 pp - male 33y old

• lived in underground cave in Texas for 6 months - entered February 14th and left September 5th

• Final 4 weeks → not in isolation → underwent physiological + psychological tests

• When Siffre woke he called the team above to turn the roof lights on

• had to clean cave every day due to white dust present in the cave that threatened his health

what kind of tests were used in Siffre

• electrodes were used to monitor his heart, brain and muscle activity

• recording blood pressure

• tasks to measure mental acuity, memory and physical dexterity - using cycle machine for 3 miles a day, threading beads on a string, fire pellet rifle(coordination), recalled random numbers, stroop test .

• shaved everyday and weighed beard trimmings to test for the male hormonal cycle

Discussion of findings - Siffre

• physical + psychological functioning deteriorated

• His sleep wake cycle ranged from 18-51h 45min most common cycle - 48h

• Siffre spent most time awake

• When Siffre left the cave he thought it was mid July when it was actually mid August

Siffre conclusions

• effects on Siffre were long lasting → long term memory lapses + weaker eyesights → shows importance of zeitgebers

• There is a tendency to develop a 48h sleep wake cycle when external cues are removed

• serious possible concerns for NASA → effects on astronauts mental + manual dexterity when disrupting sleep-wake cycles

strengths of Siffre

• quantitative + qualitative detailed data → valid + reliable

• longitudinal study → allows patterns to emerge overtime → valid + reliable

weaknesses of Siffre

• strong + artificial lights → could have acted as cues → reduces reliability + validity. Czeisler et al. kept 24 volunteers in low level lightning → found that volunteers stayed close to 24h cycle → types of lights have a significant impact

• Case study → cannot be generalised