Sleep Basics
What type of consciousness is sleep considered?
An altered state of consciousness
What does EEG measure?
Detects, amplifies and records electrical activity in the brain, as measured through brain waves.
What hormone is released to promote sleep?
Where is it released from?
Melatonin
Which group needs the most sleep?
Newborns
What is one benefit of a within-subjects design?
Controls for participant-related variables
What are the two main types of sleep?
REM and NREM
What type of data is a sleep diary?
What is one limitation?
Subjective data
Which brain structure regulates circadian rhythms?
Primarily via which sensory receptor pathway?
Suprachiasmatic nucleus (SCN)
What is the typical total sleep time for a teenager?
When is typical onset time?
9-10 hours
11pm
Difference between an extraneous and a confounding variable. Use an example for each = bonus 200 points.
A confounding variable is a type of extraneous variable that actually does affect the DV, e.g. time of test in the day control: 8am vs experimental: 4pm (we know that alertness changes throughout the day).
There is an extra difference in the IV that will affect the results.
What is one feature that distinguishes REM from NREM sleep?
Rapid eye movement in REM
Which sleep stage shows the most muscle atonia (temporary loss of muscle movement)?
REM sleep
What is an ultradian rhythm?
A biological rhythm shorter than 24 hours, e.g. a sleep cycle.
What happens to NREM Stage 3 as we age?
It decreases significantly
When is the median favoured over the mean?
When the dataset contains extreme results that create distortions (outliers).
Why is sleep considered a psychological construct?
It cannot be directly observed but is inferred from behaviour and physiology.
Why are both objective and subjective measures important in sleep research?
Objective measures provide data on physiological responses that can be used to measure brain and muscle activity, which provide insights into the stages of sleep. Subjective measures provide information about an individual's experience of the sleep episode. Looking at both data sets allows us to see a more complete picture of sleep.
How long is a typical sleep cycle?
About 90 minutes
How does REM proportion change with age? Use numbers.
It decreases from 50:50 NREM/REM as a newborn to 75:25 NREM/REM as a child, to 80:20 NREM/REM as an adolescent, adult and elderly person.
What does standard deviation measure?
The spread/variability of data
Name two differences between REM and NREM Stage 3 sleep.
REM: vivid dreaming, brain activity increases. NREM-3: deep sleep, slow brain waves.
Describe each of the four brain wave patterns that we study.
Beta: High frequency, low amplitude
Alpha: Med-high freq, med-low amp
Theta: Med-low frequency, med-high amplitude
Delta: Low frequency, high amplitude
Describe the interaction between light, SCN, and melatonin in regulating sleep.
Light information is carried by the optic nerve, which is received by the SCN. SCN uses this information to trigger the pineal gland to inhibit the release of melatonin. When melatonin is inhibited, this promotes wakefulness.
Compare the sleep patterns of infants and the elderly.
Infants: more total sleep, more REM; elderly: less sleep, fragmented, less NREM-3
Why is repeatability important?
To ensure reliability and validity of findings