Biological rhythms

Question 1

BRAC

Answer 1

physiological fatigue, focus, coffee break

Question 2

BRAC

Answer 2

Basic rest-activity cycle
Kleitman (1969)

90 minute cycle during sleep and wakefulness. During the day, rather than moving through sleep stages, we move from a state of alertness into a state of physiological fatigue.

Question 3

BRAC 2

Answer 3

Human mind can focus for a period of about 90 minutes, and towards the end the body begins to run out of resources, resulting in loss of concentration, fatigue, and hunger.

Question 4

Example of BRAC

Answer 4

In most work places, a 10:30 coffee break is given to allow 90 minute intervals of work during the working day.

Question 5

Research support (from article)

Answer 5

FRIEDMAN + FISHER: reported oral activity cycles (eating, drinking, smoking) of normal human adults, with a mean length of 96 minutes.

STERMAN ET AL.: self feeding cycles in cats that are about 23 minutes and correspond to NREM and REM cycle during sleep.

Question 6

Further research support

Answer 6

ERICSSON ET AL (2006)
- studied elite violinists and found that practice sessions were generally limited to a duration of around 90 minutes at a time throughout the day.
- aligned with Kleitman’s suggestion of fatigue at the end of 90 minute BRAC, as violinists would nap to recover from practice.
- same pattern among other musicians, athletes and writers.