Sleep & Dreams Flashcards
How much does the average adult human sleep?
7-8hrs.
What are circadian rhythms?
The cycle of biological and physiological processes that occur over a roughly 24-hour timetable. Circadian rhythms are multiple processes- rather than just one.
How many sleep stages are there?
5 - 4 nREM stages + 1 REM stage
Describe REM sleep
- This is the stage in which dreaming occurs.
- It is characterised by the rapid eye movement which happens during this stage.
- We usually have 3-5 REM episodes each night.
What was the three aims of the Dement and Kleitman study?
Study 1. To find out if dreaming occurs during REM sleep.
Study 2. To find out if the length of time spent in REM sleep correlates to the length of the dream.
Study 3. To find out if the movement of the eyes during REM sleep links to the content of the dream.
What were the hypothesise of the Dement and Kleitman study?
Study 1. More dreaming will occur during REM sleep in comparison to nREM sleep.
Study 2. Participants will report that they had longer dreams when in REM sleep for 15 minutes than they do after 5 minutes of REM sleep.
Study 3. The pattern of REM during sleep will link to the content of the dream.
Describe the overall method used in the Dement and Kleitman study.
- 7 male & 7 female participants studied in a lab. 5 were intensively studied and 4 were used to confirm results.
- The participants would each go about their ordinary days, then come back to the lab where they would sleep.
- Sensors were attached near the eyes of each participant to detect eye movement and brain waves.
- They would be woken up at various points during the night and would record if they had dreamed and if so, the content of the dream into a recording device.
Describe study 1 of the Dement and Kleitman study.
Subjects were randomly woken up during nREM sleep and REM sleep and were asked if they had dreamed or not.
Describe study 2 of the Dement and Kleitman study
Subjects were awoken either 5 or 15 mins after REM sleep began and asked if they thought their dream was closer to being 5 or 15mins long. They would be asked what happened in their dream and the amount of words they used to describe it was counted - the more words used, the longer the dream.
What were the results of study 1 in the Dement and Kleitman study
- Significantly more dreams were reported by participants awoken during REM sleep in comparison to those woken during nREM sleep.
What were the results of study 2 in the Dement and Kleitman study
- Subjects were able to accurately match the time they had been asleep to the length of their dream.
What were the results of study 1 in the Dement and Kleitman study
- Strong association between the patterns of REM and the content of the dreams was found.
Give 2 weaknesses of the Dement and Kleitman study.
- The results of study 3 have been unable to be replicated by other psychologists since, meaning the results were most likely inaccurate.
- Lab experiment - participants knew they were being studied, causing low economical validity as it was not the same as a regular night’s sleep.
Give 2 strengths of the Dement and Kleitman study.
- This study proved that dreams can be studied objectively, opening the door to future studies of dreams which are objective.
- The technique of waking participants and getting them to do tasks during different stages of sleep is a technique that is still being used to this day.
What does Oswald’s Restoration Theory claim about nREM sleep?
it restores biological processes which have deteriorated during the day.