biological rhythms: ultradian rhythms Flashcards
(15 cards)
What are ultradian rhythms?
Biological rhythms with a cycle shorter than 24 hours, such as the stages of sleep.
How many stages are there in the sleep cycle and how long does it last?
There are five stages that span approximately 90 minutes.
How can the stages of sleep be monitored?
Using an EEG to measure brainwave activity.
What happens in Stages 1 and 2 of sleep?
These are light sleep stages where alpha waves are present; in stage 2, sleep spindles occur.
What are sleep spindles?
Occasional random changes in brainwave patterns during stage 2 sleep.
What characterizes Stages 3 and 4 of sleep?
These are deep sleep or slow wave sleep (SWS) with delta waves of low frequency and high amplitude.
Why is it difficult to wake someone in stages 3 and 4?
Because of the deep sleep and slow wave activity.
What happens in Stage 5 (REM sleep)?
The body is paralysed but brain activity is similar to wakefulness, and rapid eye movement occurs.
How has research on ultradian rhythms improved understanding?
It has shown age-related changes in sleep, like reduced SWS in older people.
Why is reduced SWS in older people significant?
It may explain reduced alertness and other issues; interventions like relaxation and medication may help.
What did Tucker et al. find about individual differences in sleep?
Large differences in duration of sleep stages, especially stages 3 and 4.
What do these differences in sleep duration suggest?
They are likely biologically determined, making it hard to define ‘normal sleep’.
What is one benefit of studying sleep in lab settings?
Control of extraneous variables like noise and temperature.
What is a downside of sleep studies in labs?
Being attached to machinery may disrupt normal sleep patterns.
What question is raised about the setting of sleep studies?
Would it be better to study sleep in participants’ own homes?
