lesson 4 Flashcards
consciousness
awareness of internal and external stimuli such as feelings of hunger and pain or detection of light
wakefulness
high levels of sensory awareness, thought, and behaviour
biological rhythms
- biological rhythms: internal cycle of biological activity
– fluctuation of body temp
– menstrual cycle
– alertness level - circadian rhythm: biological one that occurs over 24h
– by suprachiasmatic nucleus (SCN)
– sleep wake cycle, linked to natural light dark cycle - controlled by hypothalamus responsible for maintaining homeostatis
suprachiasmatic nucleus
- located in hypothalamus
- brains clock mechanism
- sets itself with light info received via the retina -> synchronisation with the outside world
melatonin and sleep regulation
- regulates sleep wake cycle
- release stimulated by darkness -> makes us sleepy
- inhibited by daylight
- released by pineal gland
- cortisol: released in daylight -> alertness
jetlag and rotating shift work
jetlag
- symptoms resulting from the mismatch between our internal circadian cycles and our environment
- fatigue, sluggishness, irritability, insomnia
rotating shift work
- work schedule that changes from early to late on daily/ weekly basis
- difficult for maintaining normal circadian rhythm
- persistent feeling of exhaustion and agitation, sleeping problems, depression, anxiety
-> bright light to realign biological clocks with external environment
sleep deprivation
- sleep debt: insufficient sleep on chronic basis
- sleep rebound: sleep deprived individual will tend to take a shorter time to fall asleep during subsequent opportunities for sleep
sleep
state marked by relatively low physical activity and a reduced sense of awareness
- controlled by multiple brain ares including thalamus and hypothalamus and pons
(pineal and pituitary gland) - hormones:
– melatonin
– FSH
– LH
– growth hormone
why do we sleep
- adaptive function (evolutionary hyptheses)
– essential to restore resources that are expended during the day
– adaptive response to predatory risk, which increase in darkness - cognitive function
– focus on sleep’s importance for cognitive function and memory formation
– sleep deprivation results in disruptions in cognition and memory deficits
– impairments become more severe as the amount of sleep deprivation increases
– slow wave sleep appears to be essential for effective memory formation - sleep benefits:
– healthy weight
– lowering stress levels
– improving mood
– increased motor coordination
– improved cognition and memory formation
brainwaves during sleep
- changes during different stages of sleep
- visualised via EEG
alpha: low frequence, high amplitude, synchronised
theta: low frequency, low amplitude
delta: low frequency, high amplitude, desynchronised
sleep stages
stage 1
- transitional stage between wakefulness and sleep
- respiration and heartbeat decrease
- muscle tension and core body temp decrease
- alpha waves
stage 2
- deep relaxation
- theta waves
- appearance of sleep spindles and K-complexes
- sleep spindles: rapid burstt of high frequency brainwaves
- k-complexes: high amplitude pattern of brain activity
stage 3 and 4
- slow wave sleep
- delta waves
- respiration and heart beat decrease
REM
- rapid eye movements
- paralysis of voluntary muscles
- dreams
- brain waves similar to those during wakefulness
hypnogram
diagram of stages of sleep as they occur during period of sleep
- illustrates how an individual moves through the various stages of sleep
dreams
- sigmund freud: as access do unconsciousness
– manifest content: actual content of dream
– latent content: hidden meaning - jung: a means to tap into collective unconscious
– collective unconscious: theoretical repository of info shared by all people across cultures
– believed that certain symbols in dreams reflected universal archetypes - research:
– may represent life events that are important to the dreamer
– represent state of protoconsciousness, or virtual reality, in mind that helps a person during consciousness
– lucid dreams: certain aspects of wakefulness maintained during dreaming state
insomnia
- difficulty falling or staying asleep
- at least 3 nights a week for at least one month
- most common sleep disorder
- may be symptom of depression
contributing factors:
- age
- drug use
- exercise
- mental status
- bedtime routines
treatment:
- stress management
- change in problematic behaviour
- cognitive-behavioural therapy, focusing on cognitive processes and problem behaviours
parasomnia
- unwanted motor behaviour/experiences throughout the sleep cycle
- sleep walking: during slow-wave sleep
- REM sleep behaviour disorder: when muscle paralysis doesnt occur, high levels of physical activity, treated with Clonazepam
- restless leg syndrome: uncomfortable sensations when trying to fall asleep that are relieved by moving the legs,
- night terrors: sense of panic, scream and attempt to escape , during NREM
