Ultrafidian rhythms Flashcards
(16 cards)
What is an ultradian rhythm
a type if biological rhythm with a frequency of
more than one cycle in 24 hours
How long is each stage of sleep
90 minutes
What is stage 1 and 2 of sleep
- light sleep
person can be easily woke and brain patterns begin to slow down
What are stages 3 and 4 of sleep
- deep sleep
difficult to wake up and brain waved are even slower
What is stage 5 of sleep
- REM sleep
body is paralysed and brain activity speeds up
fast jerky movement of eyes
REM sleep is correlated with dreaming
What was the aim of Dement and Kleitmans study into ultradian rhythms
to investigate brain activity change thorough out nighttime sleep
What was the method of Dement and Kleitmans study into ultradian rhythms
7 adult males and 2 females were asked to report to the lab at bedtime where they were connected to an EEG which took measurements during sleep. pots were asked not to drink caffeinated drinks for the day before their sleep was investigated
What were the results of Dement and Kleitmans study into ultradian rhythms
they found that all ppts had periods of REM every night. Also found high incidents of dream recall when ppts were awakened during REM
What was the conclusion of Dement and Kleitmans study into ultradian rhythms
study suggests that sleep follows a typical pattern throughout the night
What is a limitation of Dement and Kleitmans study into ultradian rhythms
small sample size
What is a strength of Dement and Kleitmans study into ultradian rhythms
EEG is an objective measurement
Evaluate small sample size as a limitation of Dement and Kleitmans study into ultradian rhythms
- small sample of 9 men and 2 women meaning population validity is limited
- their conclusions that sleep follows a typical pattern throughout the night may be invalid since their sample may be unrepresentative so it may not apply to the sleep cycle of others
- however their is no evidence that this is the case. Its reasonable to argue that the small sample size isnt a sufficient reason to discount the findings
Evaluate the use of EEGs as a strength of Dement and Kleitmans study into ultradian rhythms
- EEGs provide high empiricle data
- they provide objective wvidence to show that sleep follows a typical pattern throughout night
- strength because findings provide verifiable evidence of ultradian rhytms
What are strengths of ultradian rhythms
Supported by research (D&K)
Support for sleep stages
Evaluate research support from D&K as a strength of ultradian rhythms
P: A strength of the theory that humans have ultradian rhythms is that it is supported by
research.
E: For example, Dement & Kleitman (1957) connected seven adult males and two females to an EEG machine that took measurements throughout their time asleep and they found that all participants had periods of REM every night. They also found high incidences of dream recall when participants were awakened during REM periods of sleep and if awakened during other
stages very few reported dreaming.
E: This is a strength because it demonstrates how sleep follows a typical pattern throughout the
night and suggests that ultradian rhythms do exist in humans. Replications of this study have produced similar findings.
Evaluate research support for the sleep stages as a strength of ultradian rhythms
P: There is evidence to suggest that sleep patterns may be biologically determined.
E: For example, Tucker et al found large differences between individuals’ sleep patterns, which were consistent over 11 nights in a controlled sleep lab. Individuals also responded very
differently to 36-hour periods of sleep deprivation.
E: This suggests that sleep patterns may be at least partially determined by genes.
