Most sleep research is carried out in sleep laboratories where scientific equipment can be used:
EEGs measure electrical activity in the brain, provide quantitative reports (easy to compare), are highly reliable and sleep stages can be easily identified.
EOGs measure electrical activity of the eyes - would help to identify REM sleep
EMGs measure electrical activity of the muscles - would identify loss of muscle tone in REM sleep
Other techniques used in sleep labs:
Self reports get participants to recall dreams or estimate length of dreams, emotions or level of alertness upon being woken. Good for getting information that…