Ultradian rhythms Flashcards
What is an ultradian rhythm?
A cycle that repeats more than once in 24 hours
During the awake stage, what types are the waves and explain the frequency and ampltiude
Alpha
High frequency
Low amplitude
During stage 1 of NREM sleep, what waves are taking place and what stage is it known as?
Theta waves
Drowsy stage
During stage 2 of NREM, what waves are there and what other features does the EEG scan show?
Theta waves
Sleep spindles which phase out anything happening externally
During stage 3 of NREM, what type are the waves and what is this stage called?
Theta and Delta waves
Slow-wave-sleep
During stage 4, what waves are there and label some key characteristics about this stage
Delta waves
This is when you’re in deep sleep because the thalamus turns the brain off from external influences.
During stage 5, what is this stage called, what’s the waves and key characteristics
REM sleep, this is the final stage before descending back through stages 1-4.
It involves beta waves and is used to replenish neurotransmitters and solidifies memories.
Evaluation
There has been research that confirm the 5 stages of sleep and the connection between them and dreaming
Researchers studies 9 people and awake them all during NREM and REM sleep and found that they reported dreaming in 80% of REM sleep and only 15% in NREM sleep. Dream recall was more accurate in REM sleep.
HOWEVER, the sample size was small and mainly males so lacks ecological validity.
Evaluation
Individual differences
Many people sleep for around 8 hours and experience 5 sleep cycles, however, many people sleep for much more or much less than less and hence patterns of sleep can vary from person to person and hence we cannot generalise that everybody will experience this the same.
Evaluation
nature/nurture debate
Sleep seems to be triggered by internal body mechanisms, but there is evidence for psychological factors affecting sleep patterns e.g. those suffering from depression are more likely to experience insomnia.
