Flashcards in Dement & Kleitman, 1957 (Dreams) Deck (25):
What does EEG, EOG and EMG measure?
-EEG: brain wave activity
-EOG: eye movement
-EMG: muscle movement
How many stages of sleep are there?
When you're awake, what is the wave form?
When you're in stage 1 & 2 of sleeping, what is the wave form?
When you're in stage 3 & 4 of sleeping, what is the wave form?
What is REM sleep?
-Rapid eye movement sleep, named after the rapid eye movements that occur during this stage.
-Associated with the experience of dreaming.
-Fast EEG activity like in the awake state.
What is the aim of the study?
To look at the relationship between REM sleep and dreaming.
What is the method of the study?
Lab experiment/ Quasi experiment.
Describe the participants.
9 adults (7 males & 2 females).
What were the three hypotheses?
1) To compare dream recall in REM & NREM sleep measured on EEG and EOG.
2) To see if there is a positive correlation between REM time and estimated time of dreaming.
3) To compare observed eye movements in REM with dream content.
Describe the procedure.
-Tested in a sleeping laboratory using EEG and EOG.
-Reported to the lab at their usual bedtime having avoided alcohol and caffeine but eaten normally.
-They went to bed in a quiet and dark room.
-Doorbell was used to wake them up and were asked if they had been dreaming, content of dream and say whether they had been dreaming for 5 or 15 mins. (Recorded using a recorder.)
-Sometimes a researcher would enter and ask questions to clarify what had been said.
-They were then allowed to go back to sleep.
-Woken up during REM and NREM periods.
On average, how long did they sleep for and how many times were they woken up?
-On average they slept for 6⃣ hours and were woken up 5⃣.7⃣ times per night.
What different patterns were used for awakening the five most intensively studied participants (avoid unintentional pattern)?
-2 Ps: used a table of random numbers.
-1 P: awoken during 3 REM periods and then 3 NREM periods.
-1 P: told he would be awoken during REM sleep but in fact was awoken randomly during REM and NREM sleep.
What was the IV and DV for hypothesis 1?
IV: REM or NREM sleep
DV: Dream recall
What were the results?
-80% (152) dreams were recalled during REM periods and 7% (11) dreams were recalled during NREM.
-The correlation between how long each REM period lasted and number of words used to describe it was between 0.4-0.71 for each P.
-There was a strong association between pattern of eye movement and content of dreams-35 dreams (e.g. Climbing ladders and looking up and down- mainly vertical)
-More correct estimates of length of REM than incorrect (92:19)
-More wrong estimates of dream length after 15 mins of REM than 5 mins REM (13:6).
Why were there dreams (or so they thought) during NREM periods?
They could remember the dream during REM periods for some time and so appeared during NREM sleep.
Why were there 39 occasions where no dream was recorded?
They couldn't remember the dream or was too embarrassed to say them.
What were the patterns of eye movements the researchers were looking for (hypothesis 3)?
-Mixture of vertical and horizontal
-Little or no movement
What does the study show?
Dreaming is accompanied by REM activity but it cannot be stated with complete certainty that dreaming doesn't occur at other times. The few instances of NREM dreaming can be explained by assuming participants are remembering an earlier dream but we cannot be sure dreams didn't take place in NREM.
REM is the biological basis of dreaming and that dreaming can be measured by recording REM activity but the study does not tell us whether REM causes dreaming or the other way around.
What controls were used in this study?
-When they were woken up
-Participants use of stimulants (alcohol and caffeine)
What were the strengths?
-Lab: high level of control (e.g. where they slept, when they were woken up, alcohol and caffeine intake)
-High level control= easy to draw out conclusions and reduce extraneous variables.
-Use of EEG allows precise and objective measures to be taken.
What are the weaknesses?
-Lacks ecological validity (EV) due to a lot of control (lab).
-Sleeping with electrodes attached to head is not like real life. (lacks EV)
-Artificial conditions could affect Ps sleeping patterns.
-Woken up at several times during night (low EV)
How representative was the sample?
-Sample was small (9 Ps)
-Only 2 females (hard to generalise)
-However you could argue that physiological processes are likely to be the same in all people.
-Sleep patterns, eye movements and dreaming may vary from person to person (e.g. Incorrect guesses of length of dreaming came from one person. Also there were differences in participants abilities to recall details of their dreams)
What type of data was collected?
-Quantitative: Number of Ps who could or could not recall dreams. Number of people who could or could not accurately estimate the length of their dreams.
-Qualitative: Detail of dream content.