PSYC 100- Module 7
What does SCN stand for and where is the SCN (i.e. what brain structure is it in)?
suprachiasmatic nucleus. It is in the hypothalamus
How long does a complete sleep cycle typically last, and how many complete sleep cycles do we have in a typical night?
About 5 times a night at about 90 minutes per cycle
Be sure you can discuss the role of the SCN in regulating your sleep-wake cycle.
Our melatonin levels depend on the commands coming the SCN. such as sending more melatonin when there is a lack of light in the environment. The pineal gland receives these signals from the SCN and adjusts melatonin production.
Explain the term sleep debt and list some of the consequences of having a sleep debt.
When people do not get enough sleep, they accumulate sleep debt, which is like lost sleep that the person owes their body Lack of sleep can result in decreased mental alertness and cognitive function. Sleep deprivation can also result in depressive-like symptoms. It is also associated with obesity, increased blood pressure, and reduced immune functioning.
How does REM sleep differ from NREM sleep and why is REM sleep often referred to as "paradoxical" sleep?
Brain waves during REM sleep are very similar to brain waves during wakefulness Paradoxical sleep is where the body is aroused but does not allow itself to move which is odd REM sleep periods get longer throughout the night while NREM periods get shorter
What does EEG stand for and what does an EEG measure?
Changes in brain activity while sleeping can be visualized using an EEG (electroencephalograph)
What are endogenous rhythms, what are circadian rhythms, and what are some examples of circadian rhythms in humans?
Endogenous rhythms are internal rhythms of biological activity, like a woman's menstrual cycle (recurring cyclical pattern of bodily changes that are generated from within) A circadian rhythm is an endogenous rhythm that cycles every 24 hours, like body temperature. We have a large amount of these rhythms, including peak mental alertness, peak hearing sensitivity, peak sensitivity to pain, etc.
Define chronotype and describe the two different types of chronotypes.
Individual differences in people's sleep-wake cycles, like saying you are a 'night owl' or a 'morning lark', is known as a person's chronotype
What is jet lag and how does it relate to circadian rhythms?
Jet lag is when you travel across multiple time zones, thus mismatching your internal circadian cycles with your environment
Be sure you can describe each of the four NREM stages of sleep. (The types of brain waves associated with each stage, how long each stage lasts, etc.)
Stage 1 NREM- Lasts about 5 minutes, alpha waves turn into theta waves (lower frequency, higher amplitude) Stage 2 NREM- Lasts about 15 to 20 minutes.Theta waves dominate and are interrupted by sleep spindles and k-complexes. Stage 3 NREM- 15 to 20 minutes. When there are 20% delta waves Stage 4 NREM- 15 to 20 minutes. When there are at least 50% delta waves, going up to nearly 100%
What is a hypnagogic state, and what are hypnagogic hallucinations?
The hypnagogic state is when we begin to fall asleep. We are drifting off but realize we are not sleeping yet. Hypnagogic hallucinations involve things like hearing a sudden noise that is not actually there
How do our sleep cycles tend to change over the course the night? (Hint: There are two important trends talked about in the reading).
The person will spend less time in NREM sleep and more in REM sleep