Lesson 12 - Ultradian Rhythms

Question 1

What are ultradian rhythms

Answer 1

Cycle that lasts LESS than 24 hours

Question 2

What are examples of ultradian rhythms

Answer 2

The 5 human sleep patterns

Question 3

What are the two eye movement patterns in the human sleep pattern

Answer 3

• Non-rapid eye movement (NREM) for stages 1-4

• Rapid eye movement (REM) for stage 5

Question 4

How often does the cycle repeat itself

Answer 4

Every 90 minutes

Question 5

How do the cycles differentiate from each other

Answer 5

Each stage shows a distinct EEG pattern

Question 6

What is significant about the EEG patterns of the fifth stage

Answer 6

• REM sleep is when dreaming occurs

• The EEG pattern resembles that of an awake person

Question 7

What is the Basic Rest Activity Cycle (BRAC)
-Kleitman(1969)

Answer 7

• Kleitman referred to 90 minute cycle as BRAC

• Suggested this cycle continues when awake

• We progressively move from state of alertness to physiological fatigue

Question 8

What was the procedure
-Dement and Kleitman(1957)

Answer 8

Brain activity of 9 adult PPs recorded with EEG in sleep lab

Question 9

What was controlled
-Dement and Kleitman(1957)

Answer 9

Effects of alcohol and caffeine

Question 10

What was reported
-Dement and Kleitman(1957)

Answer 10

• Distinct patterns in EEG patterns during each sleep phase

• REM sleep was highly correlated with dreaming

• Brain activity varied depending on how vivid dreams were

Question 11

Dement and Kleitman(1957) criticism

Answer 11

• Small sample size
-thus reliability of findings questionable

• However findings have been replicated
-implying link between REM and dreams

Question 12

+ Support for ultradian rhythms in elite violinists

Ericsson et al(2006)

Answer 12

• Group of elite violinists have 90 minute groups practice sessions

• Violinists napped to recover from practice

• This pattern was found among athletes, chess players, and writers

• Fits with BRAC

Question 13

(-) Individual differences in ultradian rhythms

Tucker et al(2007)

Answer 13

• Biologically determined differences exist
-possibly genetic origin

• Participants studied for 11 days/nights in lab

• Sleep duration, time taken to sleep, amount of time in sleep stage tested

• Differences were found in all characteristics

• Meaning research into this area is unreliable and findings may not be representative