Dement & Kleitman, 1957 (Dreams)

Question 0

How many stages of sleep are there?

Answer 0

5⃣

Question 1

What does EEG, EOG and EMG measure?

Answer 1

• EEG: brain wave activity
• EOG: eye movement
• EMG: muscle movement

Question 2

When you’re awake, what is the wave form?

Answer 2

Alpha waves.

Question 3

When you’re in stage 1 & 2 of sleeping, what is the wave form?

Answer 3

Theta waves.

Question 4

When you’re in stage 3 & 4 of sleeping, what is the wave form?

Answer 4

Delta waves.

Question 5

What is REM sleep?

Answer 5

• Rapid eye movement sleep, named after the rapid eye movements that occur during this stage.
• Associated with the experience of dreaming.
• Paralysis.
• Fast EEG activity like in the awake state.

Question 6

What is the aim of the study?

Answer 6

To look at the relationship between REM sleep and dreaming.

Question 7

What is the method of the study?

Answer 7

Lab experiment/ Quasi experiment.

Question 8

Describe the participants.

Answer 8

9 adults (7 males & 2 females).

Question 9

What were the three hypotheses?

Answer 9

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.

Question 10

Describe the procedure.

Answer 10

• 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.

Question 11

On average, how long did they sleep for and how many times were they woken up?

Answer 11

-On average they slept for 6⃣ hours and were woken up 5⃣.7⃣ times per night.

Question 12

What different patterns were used for awakening the five most intensively studied participants (avoid unintentional pattern)?

Answer 12

• 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.

Question 13

What was the IV and DV for hypothesis 1?

Answer 13

IV: REM or NREM sleep
DV: Dream recall

Question 14

What were the results?

Answer 14

• 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).

Question 15

Why were there dreams (or so they thought) during NREM periods?

Answer 15

They could remember the dream during REM periods for some time and so appeared during NREM sleep.

Question 16

Why were there 39 occasions where no dream was recorded?

Answer 16

They couldn’t remember the dream or was too embarrassed to say them.

Question 17

What were the patterns of eye movements the researchers were looking for (hypothesis 3)?

Answer 17

• Mainly vertical
• Mainly horizontal
• Mixture of vertical and horizontal
• Little or no movement

Question 18

What does the study show?

Answer 18

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.

Question 19

What controls were used in this study?

Answer 19

• Location
• When they were woken up
• Participants use of stimulants (alcohol and caffeine)

Question 20

What were the strengths?

Answer 20

• 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.

Question 21

What are the weaknesses?

Answer 21

• 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)

Question 22

How representative was the sample?

Answer 22

• 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)

Question 23

What type of data was collected?

Answer 23

• 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.

Question 24

What would you change?

Answer 24

• Sample: use a bigger sample (25 men and women). Easier to generalise and will apply to more people. It’ll take a lot of time and money.
• Method (Quasi/Lab): Observations in the homes of the Ps to improve EV. High EV because it will be like their natural sleeping environment. Take all machines to Ps house (time and effort). When waking them up, could wake up partners too.