Dement and Kleitman Flashcards
What is this study about?
This is a study about sleep cycles and dreaming.
What do you know about the sleep/wake cycle?
Sleep is an altered state of consciousness.
Define Circadian Rhythm.
A 24-hour sleep/wake cycle.
Define Ultradian Rhythm
A cycle that repeats more often than daily, e.g., the 90-minute sleep cycle, or periods during the day of more wakefulness.
What is REM Sleep?
A light stage of sleep where the eyes move rapidly, dreaming occurs, memory consolidation happens, and it’s also known as paradoxical sleep.
What is an EEG?
An electroencephalograph used to record brain activity and eye movements.
Who were Dement and Kleitman?
Researchers who conducted a study in 1957 on the relationship between sleep and dreaming using physiological measures.
What were the aims of Dement and Kleitman’s study?
To investigate if dream recall differs between REM and nREM sleep, if there is a correlation between dream duration estimates and REM periods, and if eye-movement patterns relate to dream content.
What were the hypotheses in the study?
- There is a connection between REM and dreaming.
- There will be a positive correlation between the length of REM and estimated length of dreams.
- There is a correlation between the direction of eye movement and dream content.
What were the independent and dependent variables?
IV: Stage of sleep (REM or nREM).
DVs: Dreaming or not, dream length estimation, anecdotal evidence of dream content.
Describe the methodology of the study.
Participants were woken up with a loud bell at various sleep stages, recorded dreams on a voice recorder, and their brain waves and eye movements were measured using EEG and EOC.
hat were the results of the study?
Dreaming is reported from REM but not nREM sleep, participants can judge dream duration, and eye patterns relate to dream content. Dream stages were longer later in the night, and REM cycles varied between subjects but were consistent within individuals.
What conclusions were drawn from the study?
Dreaming is more likely at the end of the night, eye movements and brain waves show dreams progress in ‘real time’, and this method is more objective than subjective recall.
What are the strengths of the study?
Standardized lab environment, controlled extraneous variables, objective statistical analysis, and minimized demand characteristics.
What are the weaknesses of the study?
Low ecological validity, small sample size, reliance on self-reporting, and sleep lab environment affecting sleep quality.
