Question: How do you research sleep?

Rachel Sharman answered on 7 Nov 2018:

Hi,
Great question! I research sleep a couple of different ways depending on what I need answering!
If I want to look at the brain activity during the night I do something called electroencephalograpy or EEG. EEG is where we stick small sensors to the scalp of the participant to study brain activity throughout the night. From this, we cut the sleep time (say 8 hours) into 30second pictures and stage it. This means looking at each picture of brain activity and deciding if its light sleep, deep sleep, REM sleep or wake. If you have a look in my bio I have pictures of this!
Sometimes I do something called polysomnography or PSG. This is mostly for patients and includes the EEG above but I also measure breathing to look for sleep apnoea, leg muscle movement to look for something called restless legs and sleep walking, and I measure heart rate and oxygen levels. From this I can diagnose sleep disorders.
PSG and EEG is super expensive and it takes A LOT of time so for big studies, like my Teensleep study where we had 1500 yr 10 students across 10 schools, we use questionnaires, sleep diaries, and something called actigraphy. Actigraphy is a watch device that measures movement, temperature, light, and heart rate. We can look at this data and make best guesses about actual sleep. EEG we can only really study one or two nights at a time in the lab, actigraphy means we can record for up to 3 months! Ive even sent an someone up to the Arctic with a watch to look at their sleep!