Consciousness Flashcards
What is consciousness?
Our subjective experience of the world, our bodies and our mental perspectives
What are the two main functions of consciousness?
To monitor: monitor self and environment
And control: to regulate thought and behaviour (initiate or terminate to attain goals)
What is the relationship between the reticular activating system (RAS) and consciousness?
To be conscious there needs to be a certain level of arousal.
RAS controls arousal
Explain early birds and night owls
People find their peak in alertness and arousal at differing times
Sleep changes with age?
More sleep is required at a young age - less sleep needed as get older
What is a circadian rhythm?
Biological clocks that involved around the daily cycles of light and dark
Sleep is governed by a circadian rhythm
What is melotonin?
A hormone that regulates the sleep-wake cycle
Explain the EEG characteristics or being awake
An irregular pattern.
- Beta waves - higher mental activity
- alpha waves - calm wakefulness
How many different stages of sleep do we cycle through each night?
5 stages
How long does each cycle last?
~90 minutes
What is stage 1 of sleep?
Brief 5-10 min.
Slower theta waves
RAS disconnects cortical areas from motor areas (basal ganglia)
Involves hypnagogic imagery and hypnic myoclonia
What is hypnagogic imagery?
Confused dream like images
What is hypnic myoclonia?
Sense of falling/uncontrolled muscle contractions
What is stage 2 of sleep?
10-30 min
EEG pattern of slightly slower waves but are interrupted by sleep spindles and k complexes
Muscles relax, heart rate slows, body temperature decreases, ceased eye movements
What are sleep spindles?
Bursts of low amplitude activity
What are K complexes?
Occasional slow, high amplitude waves
How much of our sleep is stage 2?
65%
Explain sleep stages 3 and 4?
Stage 3: marked by 20-50% if slow delta waves
Stage 4: sleep characterised by more than 50% delta waves
3&4 together are “delta sleep” or deep sleep
Rapid eye movement (REM) sleep?
10-20 minutes
EEG resembles the faster, waking brain pattern
Eyes move rapidly back and forth
Autonomic activity increases
Muscles are ‘turned off’
How long do we stay in REM?
25% of the night
In which stage are dreams more common?
REM sleep
Differences between nREM and REM dreams?
nREM:
- shorter
- more thought like
- repetitive
- concerned with daily tasks
REM:
- more dreams
- emotional and illogical
- prone to plot shifts
What themes are more common in dreams?
Negative themes over positive
Do dreams vary by cultural background?
Some cultural differences in dream content
What is lucid dreaming?
Awareness of dreaming. Often when something bizarre or unlikely happens
Explain the psychodynamic theory of dreaming (Freud)
Repressed wishes or unconscious desires of the ego
Includes manifest content: details of the deem itself
Latent content: hidden meaning
Criticisms of Freud’s dream theory
Why don’t we have more positive dreams
Why don’t we have more sexual dreams
Why are many dreams everyday activities
Nightmares aren’t wish fulfilment
What is the activation/synthesis theory of dreaming?
Forebrain tries to interpret signals received from other brain areas during REM
ACh activates the nerve cells in the pons - signals are sent to the thalamus and then the language and visual areas of the forebrain - amygdala activation adds emotional content.
What is the forebrain hypothesis in relation to dreaming?
Damage to the forebrain can stop dreaming suggesting interaction between forebrain area is important
What is the neurocognitive theory of dreaming?
Processing or solving problems integration of previous learned and new information and memory consolidation
The complexity of dreaming mirrors cognitive development that’s why adult dreams different from children’s dreams
What is insomnia?
An inability to fall asleep (more than 30 mins)
Waking during the night or waking too early
Is there anyone at a higher risk of insomnia?
People with depression pain medical conditions and older age
What are the short term causes of insomnia?
Stress medication’s illness shiftwork jetlag and napping during the day
What are the treatments available for insomnia?
Sleeping tablets - may be counterproductive
Brief psychotherapy
Sleep hygiene- more effective
What is narcolepsy?
Rapid and unexpected onset of sleep
Overwhelming urge to sleep
Cataplexy: complete loss of muscle tone
Plummets into REM sleep with hallucinations
What is sleep apnoea?
Blockage of the air wats during sleep. Struggling to breathe rouses the person many times throughout the night
It raises the risk of death by 17%
Normally they need a machine during sleep
What are night terrors?
Occur mostly in children
Often appear awake and highly distressed
No recollection later
Occur in stage 3 & 4 of sleep
(Nightmares occur in REM sleep)
What is sleepwalking?
More frequent in children
Can be triggered by stress
Usually involves mundane/normal behaviour
Typically occurs in nonREM sleep (3&4)
Motor activity isn’t fully disconnected
What are some effects of sleep deprivation
Depression Problems with memory and attention Hallucinations Risk of high blood pressure diabetes and cardiovascular problems Weight gain Reduced immune function
Caffeine/alcohol and sleep deprivation?
- sleep deprived people perform as badly or worse than intoxicated people
- sleep deprivation also magnifies the effects of alcohol
- caffeine can’t fix severe sleep deprivation
What are hallucinations?
Sensation experienced despite lack of environmental stimuli.
Visual cortex is activated.
What are out of body experiences?
Sensation of self leaving the body and sometimes travelling to other places or observing the body engaging in activity
Possible form of synaesthesia (crossing over of the senses)
What are near death experiences?
Sensation of passing to another realm or having your life flash before your eyes
Often culturally or religion specific
Can be triggered by electrical stimulation of temporal lobe, lack of oxygen, psychedelic and anaesthetic drugs
What are some possible scientific explanations for near death experiences
Sense of peace: flood of endorphins
Life flashing before eyes: search memories for escape
Tunnel, lights and sounds: reduced oxygen supply to the brain
What is meditation?
Direct attempts to control attention and awareness
What are the two types of meditation?
Concentrative: focus on object, breathing and mantra
Mindfulness: detached focus on thoughts, sensation, awareness. Increasingly used in mainstream therapy.
What are the benefits of regular meditation?
Increases happiness
Reduces hypertension
Reduces stress
Reduces anxiety
What is hypnosis?
Hypnotic induction rituals and suggestions to alter perception, thoughts, feelings and behaviour.
What are some common myths of hypnosis?
- people do things against their will
- hypnotic phenomena only happen under hypnosis
- hypnosis is a dream like state
- people forget what happened
- hypnosis improves memory
Explain the socio-cognitive/non-state theory of hypnosis
Social-cognitive theory of hypnosis. Theory that assumes that people who are hypnotized are not in an altered state but are merely playing the role expected of them in the situation.
The non-state theory also suggests that when in a hypnotic state, the subject is actually still in control and actively participating rather than being under the control of the hypnotist who has induced some sort of change in brain function.
Explain the dissociation theory (state theory) of hypnosis
Altered state of consciousness is induced.
Hypnosis bypasses frontal control processes that govern behaviour
Part of mind in altered state of consciousness, dissociated or the hidden observer remains aware
How can hypnosis be under in a clinical setting?
Can be used for symptom reduction and habit disorders
Not a stand alone therapy (can be used with CBT)
What are psychoactive drugs?
Induce changes in thinking, perception and behaviour by affecting neural activity in the brain
What are stimulants?
They increase activity of the central nervous system.
Tabacco, cocaine, amphetamines, methamphetapmine
What is a depressant?
Decreases activity of the central nervous system
Eg. Alcohol, Valium
What are opiates?
Give a sense of euphoria. Decreased pain, sleep. They depress the CNS All derived from poppies Increases or mimics endorphins
Eg. Heroin, morphine and codeine
What are psychedelic drugs?
Give altered perceptions, mood and thoughts. Hallucinations.
Marijuana, LSD, ecstasy
What factors affect drug action?
Biochemical: neurotransmitter release is increased, decreases or disregulated by the drug
Physiological: CNS is depressed or stimulates (resulting from neurotransmitter changes) that leads to physiological changes
Social/cultural: the setting and expectations and beliefs regarding the effects of drugs
What are the theories of addiction?
Physical dependence: drug taken to avoid negative withdrawal symptoms
Psychological dependence: drug taken to obtain the positive feelings (positive incentive)
Reward pathways and drugs
?
Drugs of dependence result in dopamine release in reward pathways in the brain.
Cocaine?
Stimulant Euphoria Suppression of hunger and pain Increases mental and physical activity Increases dopamine
Blocks dopamine re-uptake transporter - meaning more can bond with the receptors
(Meth)amphetamine (speed, crystal meth, ice)?
Stimulant
Euphoria
Decreases hinder and pain
Increases mental and physical activity
Paranoia, depression, anxiety, hallucinations
Increases dopamine
Ecstasy (MDMA)?
Stimulant
Sense of well being
Feeling close to others
Increased tactile sensation
Depression following
Increases serotonin and dopamine
Nicotine?
Stimulant
Sense of well-being and alertness
Activates receptors associated with the neurotransmitter acetylcholine
Alcohol?
Depressant
Small amounts increase well being and social interaction but reduce physiological functioning
Large effects on GABA (major inhibitory neurotransmitter)
Sedatives?
Depressant
Benzodiazepines (increase GABA), barbiturates, non-barbiturates
Neurotransmitter action depend on type
Cannabis?
Hallucinogen
Sense of well being, relaxation, changes perception
THC - acts on cannabinoid receptors that mimick the effects of endocannibinoids such as anandamide
Also increases dopamine
Social expectancies play a part in experience
Increases risk of psychosis among those with genetic susceptibility
LSD?
Hallucinogenic
Comes from fungi
Can cause synaesthesia, hallucinations and panic, paranoid delusions
Acts on serotonin and dopamine
Not very addictive - doesn’t produce compulsive drug seeking
Psilocybin?
Hallucinogenic
Magic mushrooms
Affects action of serotonin
Used during religious rituals
