1. Dement & Kleitman (1957) - Biological Approach

Question 1

What is the psychology being investigated in Dement and Kleitman? (3)

Answer 1

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

Question 2

Aim of Dement and Kleitman experiment (3)

Answer 2

1. Does dream recall differ between REM and quiescent (nREM) stages of sleep?
2. Is there a positive correlation between subjective estimate of dream duration and the length of the REM period before waking?
3. Are eye-movement patterns related to dream content?

Question 3

Type of study of Dement and Kleitman

Answer 3

lab

Question 4

What kind of measures design? Dement and Kleitman

Answer 4

repeated measures design

Question 5

IV of Dement and Kleitman

Answer 5

Whether the participant was woken from REM or nREM sleep

Question 6

DV of Dement and Kleitman

Answer 6

whether they recalled a dream of not

Question 7

To compare correlation (aim 2) what they do? What measures design? Dement and Kleitman (2)

Answer 7

Comparison of participants’ estimates of whether they had been dreaming for 5 or 15 minutes

repeated measures design

Question 8

What did Dement and Kleitman do to find out aim 3? (2)

Answer 8

Self reports were compared to the direction of eye movements observed

Question 9

Sample of Dement and Kleitman (4)

Answer 9

7 males and 2 females
—> adults
5 were studied in detail
rest were used to confirm the first 5

Question 10

Procedure of Dement and Kleitman (6)

Answer 10

Participants ate normally, arrived at the lab just before their normal bed time
Went to sleep in the dark

Electrode attached beside the eyes and on the scalp (EEG)

Participants were woken (by doorbell) at various times during the night and asked to describe their dream if they were having one, then were asked to estimate the time –> too hard for the participants so were told to choose between 5mins or 15 mins.

Participants were woken after a single eye-movement pattern had lasted for more than 1 min then asked them to report their dream.

Question 11

How was the environment highly controlled in Dement & Kleitman’s experiment? (3)

Answer 11

Doorbell used to wake participants –> loud enough to wake them up
Experimenter asked question after the recording ended
Reports were not counted as ‘dreams’ if the participant could only recall having dreamed rather than specific content.

Question 12

Different types of eye movement patterns in Dement & Kleitman’s experiment. (4)

Answer 12

mainly vertical , mainly horizontal, both vertical and horizontal, very little or no movement

Question 13

Results of Dement and Kleitman’s experiment (6)

Answer 13

1. All participants dreamed every night
2. REM lasted 3-50 minutes (mean of 20 minutes)
3. REM was longer later on at night
4. showed intermittent (irregular) bursts of around 2-100 rapid eye movements
5. Could recall their dreams from REM sleep 79.6% of the time
6. Could not recall their dreams when woken up in nREM 93.1% of the time

Question 14

Examples of dreams of participants in Dement and Kleitman’s experiment (4)

Answer 14

horizontal- watching two people throwing tomatoes at each other
vertical - throwing basketball into net- looking down at the ball / climbing series of ladders looking up and down
little of no eye movement - driving a car and staring at the road ahead, saw a man standing to the left of the road as he passed by
both- talking to a group of people / fighting someone

Question 15

Conclusion drawn from Dement and Kleitman (3)

Answer 15

1. Dreams occur during REM sleep only. Dreams reported from NREM sleep are from previous REM episodes.
2. Estimated dream duration and REM period lengths are very similar, thus it shows that dreams are not instantaneous events but rather experienced in real-time.
3. Eye movements correspond to where, and what the dreamer is looking at in the dream, hence, it explains that they are not random events.

Question 16

Strengths of Dement and Kleitman’s experiment (6)

Answer 16

1. Lab experiment –> limit uncontrolled variables –> if participants were woken up slowly they may have forgotten their dream in the process –> loud door bell helped that
2. Participants were not told about the EEG pattern / eye movements –> remove demand characteristics
3. They changed particiapnts guessing(?) time to something they can choose from (5 or 15 mins) –> easier for participants –> raised validity and reduced participants variables in ability to recall dreams
   4/ High validity - They recorded the dreams not just assumed (?) they were having dreams
4. EEG - an objective way to collect data – quantitative data (brain waves, length, eye movements)
5. Qualitative data - the dreams (can also be a weakness)

Question 17

Weaknesses of Dement and Kleitmen’s experiment (5)

Answer 17

1. Qualitative data –> it’s subjective and can affect the validity since the narrative length is not only dependent on the REM phase length but also on the participant’s expressiveness.
2. Small sample size –> low generalisibility and only 2 women
3. Deception to one of the participants –> told they would be woken up in REM but was woken randomly–> asked to record dreams may have caused distress
4. Low ecological validity –> EEG and not in their bed –> may change sleeping behaviour , also those used to taking alcohol or coffee may have change the way they sleep etc.