5.1 consciousness: the nature & functions of sleeping Flashcards
sleeping
lowest conscious level
we spend over a third of out lives sleeping
biological rhythms
as biological organisms people age and that means their lives change across time, our roles and activities won’t necessarily change dramatically throughout our life spans
life isn’t all change, other species age but also complete repetitive cycles and their biological processes across time
biological rhythms are the repetitive cycles
circannual rhythms
year long cycles of biological change
-like bears/beed cycles of activity during warm months and hibernation during winter
infradian rhythms
biological rhythms that cycle over a period longer than a day
(like female menstrual cycles)
ultradian rhythms
biological rhythms that cycle over a period shorter than a day
(like cyclical changes in our hormone levels throughout the day)
circadian rhythms
biological rhythms that cycle over a 24 hour period
like our sleeping/waking cycle
sunlight and sleep/wake cycle
exposure to sunlight plays a role in our cycles
suprachiasmatic nucleus
part of the brain which is responsible for coordinating our circadian rhythms with exposure to sunlight
SCN of the hypothalamus
receives info about lighting levels from the retinas of our eyes and sends that info to the pineal gland
pineal gland
releases hormone called melatonin
melatonin
a hormone excreted by the pineal gland that contributes to our level of alertness
more melatonin = less alterness and more sleepiness
entrainment
the synchronization of biological rhythms with external cues, such as light or temperature.
however, external cues do not modify some of our biological rhythms
endogenous rhythms
biological rhythms that do not depend on external cues
when people kept in constant artificial lighting conditions tend to follow a 24-25 hour sleep/ wake cycle
aging alters sleep patterns
younger people tend to be more alert and awake in the evening than older people, who tend to be more alert in the early morning and get drowsy earlier in the evening
across the life span humans also see a gradual decline in the amount of sleep they require
babies gets about 16 hours of sleep a day
where ages 55-90 get around 6 hours a day
what happens while we sleep
we cycle through several shorter alternating rhythms
there is a lot of biological activity going on while we sleep
polysomnography
a group of physiology measures (for biological activites)
measures of breathing rate, body temperatures, sensors for measuring muscle activity and the electroencephalogram- EEG
EEG
provides measures of brain activity at different locations across a persons scalp
EEG recordings provide the main basis for distinguishing between the different stages of biological change that occur while a person sleeps
EEG measures changes in electrical charges that correspond to the firing of neurons in the brain and thus generates a record of alternative positive and negative electrical charges
when printed graphically- these changes in electrical charge look like a jagged wave of peeks and valleys
-frequency
-amplitude
frequency of EEG
the rate of up and down shifts in the EEG waveform
amplitude of EEG
the distance in height b/w the peak and valley of an EEG waveform
beta waves
high frequency, low amplitude waves that dominate when we are awake and alert
alpha waves
as a person transitions into sleep the frequency slows down a bit and the amplitude of the waves increases a bit
this wave is common when people are drifting off to sleep or in a high state of relaxation (ex. massage or hot tub)
this is the point before the shift of the deepest level of sleep
theta waves
when we fall asleep the biological cycle we tend to follow consists of four stages
Stage 1- relative to alpha waves, the brain waves become slower and amplitude increases to form theta waves (slower breathing rate, heart rate and lower blood pressure also accompany this change in brain activity)
sleep spindles and K complexes
stage 2
after about 15 min we enter into stage 2 in which sleep spindles appear which are bursts of high frequency/low amplitude waves
K complexes also appear which are bursts of large amplitude waves
delta waves
stage 3 and 4
- around 20 min later we enter yet a deeper level of sleep in stage 3 characterized by delta waves which are low frequency high amplitude waves. this continues into stage 4 which is the deepest level of sleep and the stage at which a person will be least responsive to sounds or someone shaking them to wake up
rapid eye movement (REM) sleep
after stage 4 about one hour into sleeping the cycle proceeds in reverse to stage 1 but instead of waking up we transition from there to REM sleep. brain waves are fast during this stage, similar to the forms of an awake person. heart rate and breathing rate quickens during this stage, although body movements are suppressed during this stage, eye movements are rapid.
(stages 1-4 in non-REM or NREM sleep)
restore and repair hypothesis
the idea that sleep is to allow down time for the body to perform essential maintenance functions
(sleep deprivation gives support for this idea)
sleep deprivation
can lead to deterioration in mental and physical health
not getting enough sleep makes people less efficient when they are completing daily activities
it harms our ability to learn
weakens our immune system
problem; how much sleep we need does not relate well to the amount of energy we expend
working hard mentally and physically on a day only seems to increase our sleep requirements very slightly when compared to the amount of sleep we require after a relatively lazy day
preserve and protect hypothesis
the idea that sleep serves the function of conserving our energy and keeping us out of trouble during the nighttime
(nighttime is the most dangerous part of the day, our eyes are not meant for functioning in the dark)
preserve: animals that sleep the most are at the least risk of being eaten (ex: bats sleep 20 hours per day, predators sleep about 15 hours per day)
animals that are commonly preyed upon, like caribou, sleep
daylight savings time
our bodies are used to routine, our bodies like predictability
daylight savings time can cause problems this changes our cycle leaving us deprived of sleep until we make the adjustment
number of workplace injuries and fatal car accidents increase when people lost 40 minutes of sleep
people who do not get as much sleep as they require has a list of impairments that can happen
-worse at divided attention tasks
-impairments in concentration
-decision making is harder, problem solving, maintaining control over ones emotions and inhibition inappropriate behaviour
sleeping less than 7 hours 4 days in row is enough to observe these impairments
driving sleep deprived
is the same as drinking and driving
- one of the most common causes of fatal car accidents
- error, lack of productivity, bad choices and chaos all come from sleep deprivation
sleep displacement
when we are unable to sleep during our normal sleeping time
jet lag
Jet lag
the uncomfortable period of adjustment while our biological rhythms synchronize with a new time zone after traveling
- people are drowsy, lack concentration and more prone to getting sick
- traveling east is more difficult to adjust, because adjusting requires going to sleep earlier than normal, traveling west requires staying awake longer to get back into sync with a new time zone
sleep disorders:
insomnia
most common
extreme inability to sleep
people vary from the amount of sleep they requires so psychologists diagnose insomnia based on how rested people feel during their waking hours
-officially defined as a feeling of being unable to get enough sleep to function during the day for at least 3 months
different types of insomnia
since there are a number of ways getting enough sleep can be disrupted there are a number of types of insomnia
- onset insomnia
- maintenance insomnia
- terminal insomnia
- secondary insomnia
onset insomnia
problems getting to sleep
maintenance insomnia
trouble with going back to sleep after awakening during the night
terminal (or early morning) insomnia
trouble getting a full nights sleep from waking up too early
secondary insomnia
difficulty sleeping caused by some other primary influence, like chronic pain, drug use, anxiety or depression, or trying to sleep in a noisy or uncomfortable environment
sleep disorder:
night terrors
intense emotional reactions during sleep that cause screaming, thrashing around and waking up in a state of panic
-theses are not dreams, this sleep disorder is caused by unusually stressful situations, a heightened state of anxiety that a person finds them-self in during the day that carries over into a panic attack when they are in a non-rem stage of sleep
Sleep disorder:
movement disturbances
hard to fall asleep when you find it hard to control physical movement
restless leg syndrome
-a persistent urge to continually shift the position of ones legs
somnabulism (sleep walking)
-walking around or engaging in other activities while one is asleep
sexomnia (sleep sex)
-engaging in sexual activity during sleep, including touching oneself or others and talking dirty
REM behaviour disorder
-physically acting out the actions that one is performing as part of a dream
sleep disorders:
sleep apnea
a disorder in which a person has difficulty sleeping because of recurring episodes of not being able to breathe
is often a problem of airflow obstruction
sleep disorders:
narcolepsy
a disorder in which individuals are very sleepy or even prone to rapidly and unpredictably falling asleep during waking hours
seems to arise from a deficiency in a hormone called orexin, which is important from maintaining a state of wakefuleness
tips for maintaining good sleep hygeine
- bed should be for sleep or sex, but not for work or anything else
- don’t try too hard to sleep
- exercise early in the day
- don’t consume sleep-disruptive substances before bedtime
- put worries in a journal before bedtime, so that you can set them aside
- if you can’t sleep after 30 min, get up and do something and try again when you feel tired
- try to get up and go to sleep at the same time everyday
- when all other efforts fail, seek help from a sleep specialist
- avoid taking sleeping pills
biological rhythms
infradian,
ultradian,
circadian
polysomnography helps distinguish b/w EEG wave forms
alpha
beta
theta
delta
waves forms help distinguish between
the various stages of sleep Ex.REM and non-REM sleep
Consciousness
what we are aware of at any point of time
includes perceptions, thoughts and feelings
