Ultradian rhythms

• ultradian rhythms are biological rhythms that last less than 24 hours
• the ultradian rhythm found in human sleep follows an alternative pattern of REM sleep and NREM sleep. all five stages last a total of around 100 minutes, then the cycle repeats itself multiple times throughout the night
• Tucker et al (2007) found evidence for distinct stages of sleep. they studied ps over 11 consecutive days and nights in a strictly controlled lab environment. they assessed: sleep duration, time taken for ps to fall sleep and the amount of time spent in each sleep stage. they found large individual differences in each of these characteristics, which showed consistently across the nights
• Dement and Kleitman (1957) monitored sleep patterns of 9 adult ps in a sleep lab. brainwave activity was recorded on an EEG and they found that rem sleep was correlated with dreaming. ps' brain activity varied according to how vivid hey reported dreams being, and ps showed accurate recall of these dreams. this supports the existence of the distinct ultradian rhythm found in sleep. furthermore, replications of this study have shown similar findings
• the basic rest activity cycle was proposed by Kleitman (1969). he suggested that the ultradian rhythm found in the sleep cycle not only repeats during the hours of sleep, but also in the hours a person is awake. the difference during the day is that an individual will move through peaks of alertness and troughs of fatigue approximately every90 minutes
• anecdotal evidence does seem to support this; the human mind can only focus for periods of about 90 minutes at a time, evidences by morning coffee breaks in workplaces. towards the end of the BRAC, the body begins to run out of resources and we experience a loss of concentration, fatigue and hunger
• Ericsson et al (2006) studied a group of expert violinists. this group limited practise sessions to no longer than 90 minutes. additionally, the violinists napped the most, suggesting that responding to this ultradian rhythm increased performance
• Ericsson has also demonstrated this same pattern in a number of other samples, increasing the validity of his conclusions. this evidence suggests that humans do experience al ultradian cycle of periods of alertness as suggested by Kleitman's view of the BRAC. furthermore, individuals should work in accordance with their ultradian rhythms in order to increase productivity and performance