Lecture 8 - arousal and sleep Flashcards
What are the 4 bodily responses to stress?
- physical
- emotional
- behavioural
- cognitive
What are the behavioural effects of stress?
- Shaky voice
- tremors
- jumpiness
- escape/ avoidance
- type a behaviour (hostile, impatient, competetive)
What are the cognitive effects of stress?
- impaired decision making
- remuniation/ catastrophising
- reduced concentration
- low mental flexibility (wont change mind)
What are some stress mediators?
- coping resources and methods
- control
- predicitability
- cognitive appraisal (how you think about it) - helped by social support
What are the effects of the SNS
not about eating/ sleep, about fighting and quick responses
- pupils dilate to sleep better
- digestive system inhibited, blood needed elsewhere
- saliva inhibited
- bronchi dilate (more 02 in)
- adrenal glands secrete adrenaline and noreaderinaline
- liver pumps glucose to body
- bladder ihibited
What are effects of PNS
- just does opposite to sns - this is about conserving energy
- active when stressful stimuli has passed
- more active when we’re at rest
- both systems are active at all times, but one is more than other
•liver then secretes bile btw
What are the 2 models about physical response to stress?
- Hans Selye’s GAS model (General Adaptation syndrome)
2. Sympatho-adreno-medllary system (SAM)
Outline GAS model
General Adaptation Syndrome
- Alarm reaction - SNS, fight or flight
- Resistatnce
- Exhaustion
Outline SAM model
Tirrgered during alarm reaction
- Hypothalamus activates SNS
- SNS stimulates adrenal glands
- Adrenal glands secrete adrenaline and noradrenaline
- This activates organs - increased blood pressure, muscle tension etc
- provides energy to cope with stressor
Outline limbic sytem
Network of nuclei in brain important for emotion and memory
- Hypothalamus links to amygdala, important for interpreting negative emotions
- Thalamus is a relay station from lowe brain to cortex
- Hippcampus and amygdala important for memory
- Olfactory bulb - about smell, acts as cues for memory
Outline the Hypothalamic-pituitary-adrenal (HPA) axis
- Hypothalamus stimulates pituitary, releasing loads of hormons (including ACTH)
- Pituitary secretes ACTH (adrenocorticotrophic hormone) which triggers the release of endophins (painkillers)
- ACTH stimulates adrenal glands to secrete corticosteroids
- Releases energy supplies
What are the 2 theories of emotion
- James-Lange
2. Canon-bard
Outline james-lange
1884
• Autonomic arousal and skeletal actions come first - recognition of this physiological response = emotion
Outline Canon-Bard’s central theory
Run and are afraid at the same time
Although arousal, and recognition of emotion occur at the same time, they are independent signals sent to ANS and cerebral cortex
Outline the POlygraph
Records respiration, heart rate, blood pressure, EEG
- indicates SNS arousal, but not which emotion it is, just intensity
Can show a fake heart beat, this causes arousal as they think its theirs - supports james- lange
- Also support by Dutton and Aron (1974)
What are the evaluations of James-Lange and Canon-bard theories?
IF james-lange is correct, paralysis of internal organs would eliminate the emotional response
- LOWE & CARROL (1985) - found spinal cord lesions made less intense emotions
IF canon-bard was correct, changing intensity of physical arousal should have NO EFFECT on emotion
- but body gives feedback on emotion intensity
Define consciousness
- Awareness of external stimuli and ones own mental activity
- on a spectrum from fully concious to fully unconcious
- levels of conciousness = degree to which you are aware of mental events
Define states of conciousness
Variations of quality and nature of the mental processing avaiable to awarness
Goes from deep sleep to alert wakefulness (passive vs active)
What are the altered states of consciousness
- Sleep
- Hypnosis
- meditation
- psychoactive drugs
- depressants
- stimulants
- opiates
- hallucinogens
Outline Hypnosis
- depends on hypnotic susceptibility (10% resistant) - need a certain level of imagery - but if you dont want to do something you never will
- Changes in brain activity - alpha waves (relaxation)
- Autogenic relaxation (imagine your on a beach) vs progressive relaxation
Outline progressive vs autogenic relaxation
Autogenic
- imagine future scenarios in lots of detail, whilst relaxing
- then when you do it, cues you see will relax you
Progressive
- Tense all muscles then relax them
Can also use benzo’s as they relax you
Outline meditation
Attention focuse on one thing (ommm), so your mind is completely relaxed, body slows down
- Creates a trance like, altered state of concsiouesness
- Alpha waves and dopamine are present
- Blood flow goes to thalamus and fronal lobe
- Mindfulness meditation increases grey matter
Outline the EEG
Electroencephalograph - measures amplitude and freqeuncy of brain waves
- Alpha waves - rhythmis waves, relaxed
Outline the stages of sleep please thank you
Relaxed wakefulness
- alpha waves
- Stage 1
- slowing of heart, less muscle tension, drowsy
- need warm hadns and feet
- THETA WAVEs - Stage 2
- Theta waves, sleep spindles and K-complex
- unresponsive to env, eyes begin to roll under lids - Stage 3 & 4
- Slow wave sleep, slow breathing, heart and blood pressure reduced
- delta waves - deep, slow - REM Sleep
- Paradoxical sleep - theta and beta waves
- Brain acitivity and physiological arousal resembles wafefullness, muscle paralysis, rapid eye movement
- restores sensitivity to norepinephrine, create/ soldify nerve cell connections, consolidates memories and new skills
- where you dream - deal with redunant stuff from the day, figure out narrative later on
Outline the sleep cycle
Pass cycle of sleep 4-6 times a night, lasting 90 mins each
- as you approach waking up, REM gets longer, and stage 3 and 4 dont happen
Outline sleep patterns
Change with age
- 70+ years = 6 hrs sleep, 25% REM - sleep less, wake frequently
- infants = 16 hrs, 50% REM - lots of info to consolidate
What are the functions of sleep?
- Rest mainly from mental activity, no physical
- Consolidate memories/ skills
What can deprivation of sleep do?
- Hallucinations
- cant concentrate
- death
- increased body temp and metabolic rate (energy use)
What did Jim Horn say?
People overestimate how mucch they sleep, its not an accurate guess
What are the 3 sleep disorders?
- insomnia
- narcolepsy
- sleep apnoea
Outline insomnia
Up to 20% of population
- may be warning sign of another problem (depression, pain)
- may be having light sleep
OUtline narcolepsy
Sleep attacks - Orexin
- fall asleep for a short time (<5 min) wake up refresehed
Outline sleep apnoea
Choke in sleep - throat muscles have relaxed cause by too much sleep
- leads to daytime sleepiness, cardiovascular disease, snoring
- increase C02 in blood causes awakenings in night
What are the 7 chemicals involved in sleep
- Acetylcholine (ACH)
- Norepinephrine (NE)
- Serotonin (5-HT)
- Histamine
- Andenosine
- Benzos
- Hypocretin/ Orexin
Outline how ACH is involved in sleep
- nerve cells that are effected by this NT - cholinergic
- associated with cortical arousal
- produced in pons and basal (base) forebrain
Outline how NE is involved in sleep
- Hormone and NT
- associated with vigiliance, stress and pain, low during REM
Outline how serotonin is involved in sleep
- Associated with arousal, low during REM
- continuous, automated movement
- produced in raphe nucleus
- medulla and pons of reticular system
Outline how histamine is involved in sleep
Sleep modulation, associated with arousal (directly and via ACH)
- produced in hypohtalamus
Outline how Andenosine is involved in sleep
inhibits other NT’s and arousal
increases DElta sleep
- Caffein = antagonist, it inhibits the inhibiter of arousal so we cant sleep
- rgulates sleep/wake homestatic pressure
Outline how Benzos is involved in sleep
Promotes sleep via GABA receptor
X - increases light sleep, not resorative sleep
- Dangerous as alcohol also targets GABA
Outline how orexin/ hypocretin is involved in sleep
Produced in lateral hypothalamus
- implicated in narcolepsy
- excitatory - promots wakefulness
- basically inhibits the things that make us sleepy
How is sleep controlled in the brain?
network of structures
• Hypothalamus (ventrolateral preoptic nucleus - sleep switch)
• Brain stem
• Basal Forebrain
- directs where arousal in brain should be
which brain areas are involved in Circadian Rhythms?
Superchiasmatic Nuclues (SCN - in hypothalamus) and lateral geniculate nuclues - involved with light from retina (zeitgeiber)
SCN and pineal gland control rythm
- SCN tells pineal gland to secrete melatonin at night (winter = more sleepy)
- SCN responds to hypothalamus
What is the function of circadian rhythms?
BLood pressure, control temp, hormon secretions etc
