Dement and kleitman- Sleep and dreams

Question 1

Aim

Answer 1

1. Does dream recall differ between REM and nREM stages of sleep?
   2.Is there a positive correlation between estimate of dream duration and REM period?
2. Are eye movements related to dream content?

Question 2

Research hypothesis

Answer 2

1. there will be a significant association between REM sleep and dreaming.
2. There will be a positive correlation between estimate of dream length and REM period.
3. There will be a significant association between eye movement and dream content.

Question 3

Background

Answer 3

EEG- electroencephalogram
:A machine used to detect and record electrical activity in the nerve and muscle cells, when many are active at the same time.
EOG- electrooculogram
: Indicates the presence or absence of eye movement, in their size and direction.
REM- Rapid eye movement
nREM- no rapid eye movements
1955- Aserinsky: Revealed that participants are more likly to record visual and more vivid dream durind REM period rather thatn nREM. Showed also that thre are several stages of sleep, 1 being the lights and 4 being the deepest.

Question 4

Research method

Answer 4

Laboratory experiment and corralation controlled observation
Each study has a different method
Repeated measures design(all participants are subjected to the IV)- not all participants were studied in depth.
Natural experiment- ex we naturally sleep, and have REM cycles

Question 5

Evaluation of the method

Answer 5

methodologically it is a strength as it is in a lab and extraneous variables, such as distraction that could disturb the participant’s sleep.
However, it fails due to it artificiality. It lack ecological validity (having mundane realism).

Question 6

Sample

Answer 6

9 in total
7 males and 2 females
opportunity sampling
5 were studied tin detail and 4 were used to confirm the results obtained the the other 5.

Question 7

evaluation of sample

Answer 7

The sample size was small + they were all Americans.
However, at that time it was difficult to access participants for these studies, so it can be said that it had a good range of individual participants.

Question 8

Approach 1

Answer 8

natural experiment
repeated measures design
IV - whether they woke up from REM or NREM
DV - whether they recalled a dream or not.

Question 9

Approach 2

Answer 9

True experiment using correlational study.
repeated measures design
IV - waking participants after 5 or 15 minutes into REM sleep
DV - participants guess on dream duration (5 or 15 minutes)
correlational analysis used to cross-check participants’ estimate dream duration and the word count of their dream narrative.

Question 10

Approach 3

Answer 10

natural experiment
repeated measures design
IV - eye movement patterns
DV - dream content.

Question 11

Participants should….

Answer 11

1. eat normally through out the day
2. Not consume alcoholic and caffeine beverages.
3. Arrive at the laboratory at their usual bedtime.
   4.slept in a quiet dark room.
   5.Electrodes were attached to beside the eyes and on the scalp.
4. The wires were gathered in a pony tail to facilitate movement in bed.
5. They were woken up with a door bell

Question 12

procedure 1- dream recall

Answer 12

1. participants were woken either from REM or nREM sleep, but were not told which.
2. the choice of waking up in REM or nREM was chosen diffferently for different participants:
   : using a random number table( p: PM and KC).
   : in groups of 3 REM and 3 nREM (P: DN)
   : By decieving the participant by telling them that they would only be woken up in REM, however they were being woken up in REM and nREM randomly (p: WD).
   : No specific order the experimenter just chose (p: IR)
   After being woken the participant were asked if they were dreaming or not, if yes they would be ask to report the dream into a recorder.

Question 13

Procedure 2- Dream length

Answer 13

At first participants were woken after a variety of dream durations and asked to estimate the length of the dream, but this made the study very ambiguous and difficult for partipants to guess.
Therefore, the experimentors began to wake up participants after 5 or 15 minutes of REM sleep, and then asked the participants to guess if they were dreaming for 5 or 15 minutes.
the number of words of the dream narrative was counted- cross sectional study: if dream duration was related to dream narrative.

Question 14

Procedure 3- Eye movement

Answer 14

The direction of the eye movements was detected by the EEG electrodes around the eyes.
Participants were woken after a single eye movement pattern lasted for more than 1 minute. After they were asked to report their dream.
The eye movement patterns detected were:
:Mainly vertical
:Mainly horizontal
:Both vertical and horizontal
:Little or no-eye-movement

Question 15

operationalization

Answer 15

Operationalization: Specifiying what is dreaming or not.
:reports were not counted as dreams if the participant only recalled that they were dreaming rather than any specific content, or if they report vague and fragmented impressions of the dream.

Question 16

control REM sleep

Answer 16

The participants were never told when woken up whether they were in REM or in nREM, also if the had eye movement (and to which direction) or not.

Question 17

Results-dream recall

Answer 17

1.Participants described more often dream recall in REM and rarely in n REM.
2.When woken up in nREM, participants tended to describe feelings (pleasentness, anxiety or detachment), rather than specific dream content.
3. Participant WD was no less accurate despite being mislead.
REM:
DN- dream recall: 17
DN- no dream recall: 9
nREM:
DN- dream recall: 3
DN- no dream recall: 21

REM:
WD- dream recall: 37
DN- no dream recall: 5
nREM:
WD- dream recall: 1
WD- no dream recall: 34

Question 18

Results- Dream duration

Answer 18

1. participants were accurate when estimating dream length of 5 or 15 minutes, achieving 88 and 78 per cent respectively.
   5 minutes
   IR- Right: 11
   IR- Wrong:1
   15 minutes
   IR- Right: 7
   IR- Wrong:3
   significant positive correlation between REM and number of words of the narrative

Question 19

Results- eye movement

Answer 19

Dreams with mainly vertical eye movement:
the participant was throwing basketballs at a net, looking upwards to shoot the ball, then downwards to pick up another ball.
there were 10 dreams with little or no eye movements. Mainly reporting that they were watching something from a distance or staring at an object

Question 20

Strength-reliability

Answer 20

Reliability is high as it was a lab experiment with many controls. For example, the doorbell made people instantly wake up so that dreams wouldn’t be forgotten by slow-woken people.

Question 21

weakness- mundane realism

Answer 21

the task of being woken up several times in the night, being asked if they were dreaming and asked about dream length is unusual for participants. Lacking ecological validity.

Question 22

strength-relibility of EEG and EOG

Answer 22

Quantitative data such as brain waves, eye movement patterns, and REM sleep duration was collected through the EEG and EOG.

Question 23

weakness- ecological validity

Answer 23

participants had to sleep in an unusual environment, with electrodes stuck in their heads, which is an artificial setting for them. therefore lacking ecological validaty.

Question 24

Evaluation- Generalisability

Answer 24

Only 5 participants were studied in depth, with four more to confirm those results. Therefore the sample was small and difficult to generalize.