last less than 24 hours and can be found in pattern of human sleep. this includes REM and deep sleep.
NREM stages?
stage 1 & 2: light sleep stages- brainwaves slower and more rhythmic. stages 3&4: deep sleep or slow wave sleep difficult to wake up. Stage 5: body is paralysed and brain activity resembles that of an awake person.
Tucker et al?
Found significant difference between participants in terms of duration of each stage. this demonstrates that innate individual differences in ultradian rhythms.
Tucker et al?
carried out in a lab setting- differences instage could be due to situational difference. lack of ecological validity.
Randy garderer?
remained awaked for 264 hrs, after he slept for only 15 hrs and only recovered 25% of lost sleep. he recovered 70% of stage 4 and 25% of lost sleep.
