Lesson 11 - Ultradian And Infradian Rhythms Flashcards
What is an Ultradian Rhythm?
Ultradian rhythms refers to a biological rhythm that lasts for less than 24 hours.
What is an example of an Ultradian Rhythm?
The Basic Rest Activity Cycle (BRAC) (Kleitman (1969)).
How long is the BRAC?
90 minutes
What is the BRAC?
Researchers have found that human sleep follows a pattern alternating between Rapid Eye Movement sleep (REM) and Non-Rapid Eye Movement sleep (NREM) which repeats itself every 90 minutes.
How many stages are there in BRAC?
5
What stages are in REM and which ones are in NREM?
REM - stage 5
NREM - stage 1, 2, 3 and 4
How does the EEG pattern differ in deep sleep?
Their brainwaves slow and their breathing and heart rate decrease.
How does the EEG pattern differ in stage 5 (REM)?
- EEG pattern resembles that of an awake person as this is the stage in which dreaming occurs.
What is the BRAC like when we are awake?
When we are awake, instead of moving through sleep stages, we move progressively from a state of alertness to a state of psychological fatigue because the human mind can only focus for about 90 minutes where, at the end of those 90 minutes, our body begins to run out of resources resulting in a loss of concentration, fatigue and hunger.
What is an advantage of Ultradian Rhythms?
Ericsson et al. (2006) found support for Ultradian Rhythms where a group of elite violinists chose to limit their rehearsals to 90 minutes. These violinists frequently napped to recover from the rehearsal where the best violinists napped more. The same pattern was found among athletics, chess players and writers which, therefore, supports BRAC and the idea that the human mind can only concentrate for 90 minutes.
What is a weakness of Ultradian Rhythms?
Tucker et al. (2007) suggested that there are individual differences in ultradian rhythms which are biologically determined and may even have a genetic origin. Participants were studied during over 11 consecutive days and nights in a laboratory environment where researchers found differences in sleep duration, time taken to fall asleep and the amount of time spent in each sleep stage.
What are Infradian Rhythms?
Infradian rhythms refers to a biological rhythm that lasts for longer than 24 hours.
What is an example of an Infradian Rhythm?
The menstrual cycle
How long is the Menstrual Cycle?
The menstrual cycle lasts for about a month BUT there are considerable variations in its length. Refinetti (2006) discovered that some women experience a 23 day cycle, some a 36 day cycle, but the average is 28 days.
Describe the menstrual cycle over the 28 day period?
Hormones regulate the menstrual cycle. Ovulation occurs roughly halfway through the cycle (14 day mark), when oestrogen levels are at their peak, and usually lasts for 16-32 hours. After ovulation finishes, progesterone levels increase in preparation for the possible implantation of an embryo into the uterus.
