1. Physiological Psychology The Core Studies
Dement & Kleitman
Physiological Psychology
The Core Studies

2. Background REM Characteristics of REM
Rapid Eye Movement
Characteristics of REM
Body is paralysed
eyes & brain very active
dreaming
deepest type of sleep
EEG – Measures the gross electrical activity of the brain
NREM
The sleep cycle

3. Benefits & Limitations of using an EEG machine
Very scientific way of measuring and finding results therefore makes the study more reliable
Collects quantitative data that can be analysed statistically
The use of an EEG involves the attachment of electrodes to the participant’s scalp. This may interfere with sleep patterns so results may not reflect an individuals normal sleep pattern
An EEG doesn’t explain why the electrical activity is taking place. The activity may not be caused by the participant dreaming but by some other factors

4. Aim & Hypotheses
The aim of the study was to investigate dreaming in an objective way by looking at the relationship between eye movements in sleep and dreamers-recall Hypotheses There is a significant association between REM sleep and reported dreaming There is a significant positive correlation between estimation of dream duration and measurement of REM sleep There is a significant association between the pattern eye movement and reported dream content

5. Sample
9 adults 7 males 2 females All from USA No age or gender details recorded 5 participants were studied in detail 4 were studied to confirm the results The 5 stayed between 6-17 nights in the lab The 4 stayed between 1-2 nights in the lab

6. Method
Snapshot Lab experiment IV’s Whether they were woken from REM/NREM Whether they were woken after 5 or 15 minutes of sleep Type of eye movement pattern DV’s Whether they could recall, if so, the detail Their choice of 5 or 15 minutes Recall

7. Method
Participants were asked not to consume caffeine containing beverages as caffeine is a known stimulant which can affect an individual’s sleep pattern. Controls Same EEG machine, all restricted from alcohol and caffeine, same laboratory, all were woken by a doorbell

8. Procedure
Participants were restricted from consuming caffeine and alcohol upon the day of arrival. The participants arrived to the lab at their normal bedtime. They were then fitted with EEG electrodes (to measure brain activity) and EOG electrodes (to measure eye movement). The participants slept with the electrodes tied in a pony tail around their head, which ran into the researchers room and fed into the EEG machine. After falling asleep, the researchers woke participants up from either REM/NREM and asked them if they had a dream. If so, they had to recall it into a Dictaphone. Participants fell back to sleep and were then awoken following 5 or 15 minutes of REM sleep. They then had to say their estimation and recall the dream. After falling asleep again, researches assessed a one minute session of REM of the participants and recorded movements as “vertical, horizontal, both, little movement”. Participants were then woken again and asked to recall their dream

9. Results
REM awakenings
NREM awakenings
Dream recall
No recall
152 39 11
149
Quantitative and Qualitative data were gathered in response to hypothesis 1 and 2 but only qualitative data was recorded for hypothesis 3
More dreams were recalled from REM than NREM sleep (152:11) (1)
Less dreams were recalled from NREM sleep than REM sleep (149:39)
Participants could accurately estimate dream duration.
There was a positive correlation between length of recall and REM length (2)
Participants’ eye movements were strongly related to dream content. E.G. one participant mentioned looking up and down a ladder (vertical), another said about watching a tomato fight (horizontal)

10. Conclusions
Dreams are most likely to only occur in REM Any dreams that are recorded from NREM are due to remembering the last REM episode People can accurately estimate dream duration Eye movements are related to dream content We dream in real-time

11. Strengths of the study
Both types of data are collected (quant : number of dreams recalled after awakenings in REM and NREM sleep, accuracy of dream length when awakened after 5 or 15 minutes of REM sleep) Lab experiment so extraneous variables are highly controlled Due to the high control we can establish cause and effect of the IV Very scientific so it can be seen as reliable

12. Weaknesses of the study
Low ecological validity because participants are in an extreme artificial environment (e.g. sleeping wired up to an EEG machine, being restricted from caffeine and alcohol) Dream recalls may not have been entirely true due to people feeling annoyed, wanted to get back to sleep quickly, being embarrassed etc.. Very small sample & only 2 women No control of participants’ diet

13. Evaluation of method
High control Scientific so can be seen as reliable Both data types were collected However it is very low in ecological validity The sample is not generalizable enough, especially to women

14. Evaluation of sample
Due to it being a small sample it allowed researchers to put more detail into each subject
It included both genders
However it was definitely not generalizable enough to women
All were from the USA so ethnocentrism is a problem
No background about participants which may have affected sleeping patterns

15. Changes to the study
A change that I would make to the study is to involve more female participants. In the original study, only 2 females were studied. A problem with this is that results and conclusions collected are not generalizable enough to women as only 2 provided results. I would include 10 women and 10 men through an advert in a newspaper. This way more women would be involved, and the experiment wouldn’t be gender bias.
Another change I would make to the study is to improve ecological validity. The original study took place in a lab and so participants were not in their normal sleeping environment, ultimately reducing ecological validity. I would conduct the study at participants’ homes to increase E.V levels.

16. Effects of the changes
By involving more women into the sample, this means that the study will be much more generalizable to the wider population, and women. Results collected may show that women have different REM patterns and experiences during sleep and so may benefit conclusions drawn from the study. However a problem could be that it may be hard to find participants, perhaps females, that are willing to be studied. By doing the study at participants'’ homes, this means that they are in their natural environment, in their normal bed and so hopefully E.V would raise due to the study being more realistic to the participants’ everyday life. However in practical terms, it could be extremely hard to carry out, especially with the EEG machine.