Please enable JavaScript.
Coggle requires JavaScript to display documents.
BIOPSYCHOLOGY- ultradian rhythms- the stages of sleep - Coggle Diagram
BIOPSYCHOLOGY- ultradian rhythms- the stages of sleep
untradian rhythms-
ultra= beyong, dian= day. ultradian rhythms are biological processes that happen more than once every 24 hours
EEG brain wave features
frequency- hoe close the waves are to one another (waves per second in Hz)
amplitude- size of the brain wave (change in voltage)
stages of sleep
stages 1-3 are NREM sleep- termed N1,N2,N3. After passing back through N2 and N1, stage 4 is REM sleep- where most dreams occur. One cycle takes around 90 minutes and repeats 4-5 times over the course of one nights sleep.
sleep becomes deeper from N1 to N3- less easily woken and brain frequency slows with increased amplitude
N1- this is the sensation of falling asleep. easy to wake and the body may have sudden movements called hypnic jerks. there could be a sensation of falling with mild visual or auditory hallucinations. EEG shows theta waves, slow frequency but high amplitude in comparison to being awake
N2- deeper sleep than N1. harder to wake, the body is relaxed, HR and body temp are lowered and the eyes are still. EEG shows slow theta, but theres occasional activity called sleep spindles and K complexes
N3- deepest sleep. very hard to wake, body is most relaxed with HR ar its lowest. identified on EEG by the presence of slow frequency and large amplitude delta waves (slow wave sleep)
REM- brain returns to active state passing back through N2 and N1. REM is similar to wakefulness as seen on EEG but the body is paralysed. characterised by rapid eye movement and associated with dreaming, as when woken people report vivid dreams in this stage
the brain returns to N1 after REM, repeating the cycle up to 5 times in 1 night. eah cycle tends to include a larger proportion of REM sleep and a shorter duration of N3
research eveluation.
Dermot and Kleitman
study 1. EEG recordings made of 33 Ps over a nights sleep. brain waves followed a cyclic pattern of activation with bodily relaxation occuring during slow wave sleep and REM during periods of high activation
study 2. 9 Ps woken at different stages in their sleep cycle reported dreaming more frequently when woken in the REM stage
Shapiro
ultramarathon runners showed longer sleep after intense physical activity. also there was an increased proportion of slow wave sleep, suggesting N3 is for physical recovery of the body.
Haider
EEG of 10 patients who were recovering from drug overdose showed increased REM sleep which suggests REM is for recovery of the brain
general evaluations of untradian rhythms
NEGATIVE- the overall pattern of sleep stages is consistent however there are some individual differences with newborns spending 80% of sleep in REM compared to 20-25% in adults. this suggests the stages of sleep arent a simple process but they adapt to the developemental needs of an individual
POSITIVE- technology and devices based on understanding sleep stages have been developed. these track sleep and help people improve their sleep. avoiding waking up in stage 4 stops people feeling groggy. this technology leads to happier, healthier and more productive population
NEGATIVE- some think that circadian and ultradian rhythms are connected and shouldnt be treated as separate processes. Czeilsler showed that the longest period of REM sleep coincides with the lowest point in circadian body temperature cycle. This could mean both processes use the same internal body clock also known as the endogenous pacemaker- the supercharismatic nucleus
