Infradian Rhythms/ Ultradian Rhythms Flashcards
What are infradian rhythms? provide an example.
These are a rhythm that lasts longer than 24 hours, e.g the menstrual cycle is a monthly rhythm.
What is the main example of a weekly cycle in infradian rhythms, why is this?
Male testosterone levels tend to peak at the weekend, this may link to the increased amount of sex young couples have here.
What did Halberg et al. (2002) report on regarding infradian rhythms?
Reported on a seven-day cycle of blood pressure and heart rate in humans.
What is the most well-known monthly cycle for indradian rhythms?
What did Refinetti (2006) find regarding these?
The menstrual cycle
Refinetti found that there are large variations in duration, from 23–36 days.
How does the menstrual cycle work? (oestrogen/progesterone)
It typically lasts for 28 days
Oestrogen levels increase/ trigger ovulation, about halfway through.
Progesterone then increases, stimulating the uterus to get ready for the implantation of a fertilised embryo.
What is the McClintock effect?
Women who begin living together will experience the increasing synchronisation of their menstrual periods the longer they live together.
What did Russell et al. (1980) do with individual women and then on a larger scale that involves the menstrual cycle? What was the result?
They placed the sweat from one woman on the upper lip of another woman, the second woman’s menstrual cycle synchronised with the first woman.
The same results were obtained from the larger group.
What did Magnusson (2000) find that is an example of an annual rhythm regarding infradian rhythms?
Found a seasonal difference in the mood of humans, especially women.
What is Seasonal Affective Disorder (SAD), studied by Magnusson (2000) in regards to infradian rhythms?
This is when a significant number of people become depressed during the winter months.
What are ultradian rhythms and provide an example
These are rhythms that last for less than a day
Most common e.g is the 5 stages of sleep in the sleep cycle.
What did Dement and Kleitman run a study on and what did they identify from this?
They ran a sleep study using EEG and identified the 5 stages of sleep have different EEG recordings, meaning, EEG can be used to find out what stage of sleep a person has reached.
What are the 4 categories of sleep? What does the 4th stand for?
NREM Stage 1/2 - light sleep
NREM Stage 3 - deep sleep
REM - rapid eye movement during dreaming
What occurs in the first 2, light sleep, NREM stages in the sleep cycle?
Stage 1 - lots of alpha waves that are then replaced eventually with more theta waves
Stage 2 - mostly made of theta waves with some sleep spindles (may be linked to memory + learning )
What occurs in the 3rd, deep sleep, NREM stage in the sleep cycle?
What hormone is released and what does it do?
Stage 3 - made up of delta waves and we can see someone’s respiration/heartrate drop. It is very hard to wake someone up in this stage. Growth Hormone is released to trigger the repair of the body/ brain.
What does REM sleep stand for and when does it occur?
Rapid Eye Movement during dreaming
Occurs after around 90 minutes after the 3 stages of NREM sleep have passed.
What occurs in the 4th, deep sleep, stage of sleeping that is REM ?
Brain waves are very similar to those seen when the person is awake, the muscle systems are paralysed to prevent the person from moving during their dreams.
Includes Theta, Beta and Gamma waves.
At which stage does restorative / slowwave sleep occur?
NREM sleep stage 3
What did Tucker et al. (2007) find they can do regarding the sleep stages, and what did they find from this? What does this finding suggest?
They found that the sleep stages could be measured under lab conditions
From this they found individual differences in sleep patterns are due to genetic factors. Suggests biological systems that control sleep may be genetic in nature.
What was the concept that Kleitman (1969) proposed, regarding the sleep cycle in ultradian cycles?
The Basic Rest Activity Cycle (BRAC).
What is the concept of the BRAC? What do we feel when we are fatigued?
The concept of this is that we move from feeling alert to feeling fatigued over 90 minutes, due to the sleep stages/ BRAC lasting 90 minutes on average.
When we feel fatigued, we start to feel hungry so seek to replenish our energy stores.
What did Kleitman suggest about the 10:30 am break regarding the BRAC?
If the concept of the BRAC is true what does this mean in regards to the human day?
He suggested that the 10:30 am break was so common as it’s 90 minutes after we start working.
If the concept is true, it means the human day is roughly split into 16, 90 minute cycles.
How did Ericsson et al. (2006) find support for the BRAC and what were their two findings that supported it?
They studied elite performers
E.g expert violinists keep practise sessions of 90minutes, and that they regularly nap after these sessions to preserve learning.
What is the order in waves from wakefulness to REM sleep?
Beta, Alpha, Theta, Delta, Gamma
What are the 4 stages of consciousness in regards to sleep?
Conscious mind
Gateway to subconscious mind
Subconscious mind
Unconscious mind/ collective consciousness.
What are the 5 things that occur during the ‘conscious mind’ stage? (stage 1)
-Normal waking state of consciousness
-Alertness
-Concentration/focus
-Cognition
- 5 senses
What are the 5 things that occur during the ‘Gateway to Subconscious mind’ stage? (stage 2)
-Deep relaxation/ light meditation
-Relaxation, with eyes closed
-Visualisation
-Creativity
-Super learning
What are the 5 things that occur during the ‘subconscious mind’ stage? (stage 3)
-Usually light sleep, as well as REM sleep state
- Deep meditation
- Intuition
-Memory
-Visual imagery
What are the 5 things that occur during the ‘unconscious mind’ stage? (stage 4)
-Usually deep sleep
-Dreamless state
- Automatic self healing
-Immune system function
-Collective consciousness
How are Beta waves involved in the sleep cycle?
Wakefulness / Alertness
These are replaced with alpha waves, when body is relaxed.
How are Alpha waves involved in the sleep cycle?
These increase when the body is relaxed, typically with the eyes closed.
These are then replaced by Theta waves, in the transition into NREM S2
How are Theta waves involved in the sleep cycle?
These are involved in the transition wakefulness to REM sleep
How are Delta waves involved in the sleep cycle?
These are involved most prominently in S3 of NREM sleep, which is restorative/ slowwave sleep.
How are Gamma waves involved in the sleep cycle?
These are involved in wakefulness, but mainly REM sleep.
