PSYA01H3 Study Guide - Sleep Deprivation, Sleep Spindle, Sleep Paralysis
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Sleep and Dreaming: Good Night, Mind
Sleep can produce a state of unconsciousness in which the min and the brain apparently
turn of the functions that create experience
Dream consciousness involves a transformation of experience called altered stated of
Altered stated of consciousness: a form of experience that departs significantly from the
normal subjective experience of the world and the mind
These states can be accompanied by alterations in body image, changes in thinking etc.
The pre-sleep consciousness is called the hypnagogic state-the sudden jerk
Cardian rhythm is the naturally occurring 24 hour cycle
EGG recordings revealed a regular pattern of changes in electrical activity in the brain
accompanying the circadian cycle
During waking, these changes involve alteration between high frequency activity during
alertness and lower-frequency activity during relaxation
There are five sleep stages. The first stage of sleep, EEG moves to a frequency pattern
lower than alpha waves. The second sages of sleep, these patterns are interrupted by short
bursts of activity called sleep spindles and k complexes. The deepest stages of sleep are 3
and four, known as slow-wave sleep, in which EEG pattern show activity called delta
The fifth sleep stage, REM sleep, a stage of sleep characterized by rapid eye movements
and a high level of brain activity, The EEG patterns suggest that the mind at this time is
active as it was during waking.
In the first hour of sleep you fall into the fourth, deepest stage of sleep.
Sleep Needs and Deprivation:
Robert Stickgold found that people learning a difficult perceptual task kept all night after
they finished practicing the task, their learning of the task is wiped out
Sleep following learning appears to be essential for memory consolidation
Memories normally deteriorate unless sleep occurs to help keep them in place
A few hours of sleep deprivation each night might have detrimental effects: reducing
mental acuity, reaction time etc.
Rem sleep deprivation causes memory problems and excessive aggression
Deprivation from slow-wave sleep creates more physical effects such as tiredness and
Sleep is potentially costly in the course of evolution
Insomnia: difficulty in falling asleep or staying asleep. This is caused by stressful events.
Sleeping pills are often reduce however they reduce the proportion of time spent in REM
and slow-wave sleep
Sleep apnea: disorder in which person stops breathing for a brief period while sleeping. A
person with apnea snores, apnea involves an involuntary obstruction of the breathing
Somnambulism-sleepwalking: occurs when a person arises and walks around while