Ultradian Rhythms Flashcards
What are ultradian rhythms?
Biological rhythms that last less than 24 hours
How many stages does sleep have?
5 stages
How long does it take to complete the sleep cycle?
90 minutes
Describe stage one
It varies between 5-15 minutes, body released, heart rate slows, muscles relax and people are still easily woken
Describe stage two
It varies between 5-15 minutes, there are short bursts of activity, the body continues to relax, it is still easy to wake someone
Describe stage three
It varies between 5-15 minutes, there are less sleep spindles, the body relaxes further and it becomes harder to wake people
Describe stage four
It lasts 40 minutes, the level of activity is slower, metabolic rate is low, it is difficult to wake and growth hormone are released
Describe REM
It initially lasts 15 minutes but lengthens throughout the night, there is more brain activity than in any other stage, complete relaxation, dreams, irregular breathing and heart rate
What is a study to support ultradian rhythms?
Deter and Kleitman. They were the first to document what occurs in REM sleep. They asked 7 adult male participants and 2 female participants to report to a sleep lab before bedtime to be connected to an EEG
What were the findings of Demet and Kleitman study?
Everyone had periods of REM sleep and they found high incidences of dream recall if the participants were awakened during REM sleep. It was also found that sleep follows a typical pattern throughout the night
What are two strengths of ultradian rhythms?
There is much replication of Demet and Kleitmans study as similar findings have been found and EEG is an objective measure therefore it’s scientific
What are two limitations of ultradian rhythms?
Research was in a sleep lab so lacks ecological validity and dreaming is difficult to measure as you can only ask people which leads to social desirability
