Dement and Kleitman

Question 1

1. Dement and Kleitman’s study on sleep linked REM activity to dreaming. Describe two pieces of evidence that supported this link. (4)

Answer 1

Any two of the following:

1) High incidence of recall of dreaming during REM periods, and low incidence during NREM periods. Most of recall in NREM was within eight minutes of the end of an REM episode.
2) Participants were 82% correct in estimating whether REM activity lasted for 5 or 15 minutes. There was also a significant correlation between the duration of REM activity and the number of words used to describe a dream.
3) Eye movement patterns and visual imagery of the dream were linked, for example horizontal eye movements linked to a dream about two people throwing tomatoes.

Question 2

2. In the study of sleep by Dement and Kleitman there was some evidence that dreams also occurred in NREM sleep.
   a) Explain how they collected this evidence. (2)

b) How did they explain the dreams being reported in NREM? (2)

Answer 2

1) The P was awakened during NREM sleep and the P was instructed to speak into a recording machine near their bed and A) state whether they had been dreaming B) describing, if they could, the content of the dream and C) saying, if they were dreaming for 5, or 15 minutes.
2) The few instances of NREM dreaming can be best explained by assuming that the memory for a dream persisted for some time and thus appeared to occur during NREM sleep.

Question 3

3. Dement and Kleitman used an electroencephalograph (EEG) to record sleep activity.
   a) Explain what the EEG shows. (2)

b) Describe one limitation of using an EEG to investigate dreaming. (2)

Answer 3

3) The EEG shows gross brain activity, machine provides the summary of electrical activity from one area of the brain. It records brain waves as a measure of depth of sleep.
4) EEGs only provide general information about electrical activity in the whole brain. It is limited because it can’t really see the brain at work.

Question 4

4 a) Identify two of the controls used by Dement and Kleitman in their study of sleep and dreaming. (2)

B) Outline why controls are used in psychological research. (2)

Answer 4

5) Controls: the environment in which Ps slept, the manner in which they were woken and their caffeine and alcohol intake.
6) Controls are used in psychological research so that they do not affect the results of the experiment and researchers are able to establish a cause and effect relationship between the IV and DV.

Question 5

5. In the study by Dement and Kleitman, participants were told to abstain from two substances on the day of the experiment.
   a) Identify these two substances. (2)

b) Outline one problem with this instruction. (2)

Answer 5

7) Caffeine and alcohol.
8) Informing Ps not to consume these two substances may affect their normal sleep patterns as they may normally have these during the day. Therefore sleep patterns observed may not reflect their everyday sleep patterns.

Question 6

6. a) Identify one of the hypotheses of the Dement and Kleitman’s study on sleep and dreaming. (2)

B) Outline the result of the study in relation to this aim. (2)

Answer 6

Any one of the following:

1) Ps will recall dreaming significantly more during episodes of REM sleep than in comparison to NREM sleep.
2) There will be positive correlation between the length of REM periods and subjective dream-duration estimates.
3) There will be a link between eye movements and the content of the dream.

1) High incidence of recall of dreaming during REM periods, and low incidence during NREM periods. Most of recall in NREM was within eight minutes of the end of an REM episode.
2) Participants were 82% correct in estimating whether REM activity lasted for 5 or 15 minutes. There was also a significant correlation between the duration of REM activity and the number of words used to describe a dream.
3) Eye movement patterns and visual imagery of the dream were linked, for example horizontal eye movements linked to a dream about two people throwing tomatoes.