Ultradian Rhythms AO3

• Difficult to study because of individual differences
• Tucker found big differences in duration of stages 3 and 4 between participants
• This was in a lab, which suggests there are biological differences (not just situational, as controlled setting)
• Outside a lab, the situation may contribute to sleep cycle
• Sleep cycle hard to investigate in lab - participants have to be attached to monitors
• Sleep that takes place may not be reflective of sleep without the distracting monitors
• Conclusions drawn may lack validity, as the research they are based on may lack validity (ecological in this case)
• Gives us an improved understanding of how the sleep wave cycle changes as people age
• Growth hormone is produced during sleep, therefore older people sleep less
• This explains reduced alertness in old age
• This info can be used to introduce strategies to help people sleep more when older