Please enable JavaScript.
Coggle requires JavaScript to display documents.
Dement,W. & Klietman,N. 1957
The relation of eye movement during…
Dement,W. & Klietman,N. 1957
The relation of eye movement during sleep and dream activity
background
Aserinsky and Kleitman (1955) were first to use an EEG to investigate sleeping and dreaming. They found that humans have several sleep stages during the night, which alternate from REM (rapid eye movement) to NREM (non-rapid eye movement). They reported that those participants who woke up during the REM sleep stage reported more vivid, visual dreams.
Freud argued that the function of dreaming was to preserve sleep by unconsciously fulfilling wishes which would otherwise upset and therefore disturb the sleeper. He then argued that dreams are the ‘royal road to the unconscious. Cognitive and psychological explanations for dreaming.
Cognitive approach might explain how dreaming is a way of dealing with our problems such as those relating to work and personal life. Physiological approach might explain dreaming as the result of random firing of neurons which create an image which we put meaning to.
A typical sleeper goes through different levels of sleep in a cyclic fashion between 5 to 7 times. Level 1 & 2 are light sleep characterised by irregular eeg pattern. Level 3 & 4 are deeper levels and are characterised by regular wave patterns. Stage 4 is called slow wave sleep/deep sleep. After stage 4 the sleeper goes through the sleep staircase to stage 2 and there is a period of REM sleep lasting for 15 to 20 minutes.
Sleep states alternating during the night starting with a rapid descent into deep sleep, followed by progressively increased episodes of lighter sleep and REM sleep
general
procedure
Prior to the study, the 9 participants 7 adult males and 2 adult female. 5 were studied intensively, while the other 4 were studied to back up finding of the main 5. The participants were studied under a controlled laboratory conditions. participants were instructed to abstain from drinking caffeinated beverages and alcohol. They were expected to arrive at the laboratory just before their usual bedtime. They had to sleep in a dark room an EEG was used to amplify and record the signals of electrodes attached to their scalp and face, two or more electrodes were attached near the participants eyes to record electrical changes caused by eye movement. two or three further electrodes were attached to the scalp to record brain activity which indicates the participants depth of sleep and the wires gathered in a ponytail.
results
.
It was reported that dream stages last from 3 to 50 minutes with a mean duration of 20 minutes and they were typically longer in the night. There were bursts of around 2 to 100 rapid eye movements.
-
Sleep cycles varied from 70 to 104 minutes, mean duration of 92 minutes.
Participants tended to return back to NREM when woken on NREM but usually when woken in REM, did not dream until the next NREM stage
The REM period occurred at regular intervals during the night, though each participant has their own pattern
hypothesis
testing for hypothesis 1: there will be a significant association between REM sleep and dreaming
at various times during the night during both REM and NON-REM sleep the participants were awakened to test their dream recall. they were woken up by a loud doorbell ringing near their beds. the participants had to speak into a tape recorder by their bed. they were instructed to first state wether or not they had been dreaming and then had to report the content of the dream. the participants were only recorded as having dreamed if they were able to relate a coherent and relatively detailed description of the dream content.
different participants were woken up at different schedules . two were woken at random.one was woken three times in REM then three times in NON-REM. one was woken up at random but was told he was woken up during REM another one was woken up at experimenters whim.
experimenter didn't communicate with participants during the night. preventing bias the participants were never told, after wakening wether their eyes had moved or not
testing hypothesis 2: there will be a significant positive correlation between the estimate of duration of dreams and the length of eye- movement
the participants were also woken up either 5 minutes or 15 minutes into the REM period, and asked to say whether they thought they had been dreaming for 5 minutes or for 15 minutes
testing hypothesis 3: there will be a significant association between the pattern of eye movement and the content of the dream The participants were woken up as soon as one of 4 patterns of eye movement had lasted for at least one minute. on waking, the participant was asked to describe in detail the content of their dream.the patterns that prompted an awakening were:
- mainly vertical eye movement
- mainly horizontal eye movement
- both vertical and horizontal eye movement
- very little or no eye movement
-
evaulation
strengths -
- lab experiment; had control over extraneous variables
- no demand characteristics as the experimenter did not communicate with the participants at night
- the operationalisation of what they counted as a dream raised validity as they could be more sure of the details being recorded were dreams.
weaknesses
- subjective: the use of self report when describing their dreams,
- deception: of participant WD who was misled on being woken up during REM sleep but was being woken in random
- sleeping in a lab and with all those wires would cause destress to participants
-
-