AICE Psych: Dement and Kleitman (Sleep and Dreams)

Outline the 4 aims of the study.

1) To see if dream recall occurs during REM or non-REM sleep.

2) To see if there is a link between the estimate of dream length and the length of the REM period.

3) To see if the pattern of eye movement (vertical/horizontal) is related to dream content.

4) To see if there is a positve correlation between the length of REM sleep and the number of words given in a dream narrative.

What research method(s) were used? State and describe.

• Experiment: has IV’s and DV’s in relation to REM sleep and dream content/duration

• Interviews: Researchers occasionally interviewed participants on the content of their dreams, semi-structured.

What was the research design used?

Repeated measures design; participants experienced every IV level.

Outline the IV and DV for aim 1.

IV: whether the participant was woken during REM or N-REM sleep.

DV: whether the participant could recall the content of theirdream in reasonable detail (yes or no)

Outline the IV and DV for aim 2.

IV: whether the participant was woken up 5 or 15 minutes after the onset of REM.

DV: perception of whether they had been dreaming for 5 or 15 minutes.

Outline the IV and DV for aim 3.

IV: Eye movement pattern before they were woken up.

• A) mainly vertical eye movements

• B) mainly horizontal eye movements

• C) both vertical and horizontal eye movement

• D) very little/no eye movement

DV: dream description

Outline the co-variables for aim 4.

Co-variable 1: number of minutes spent in REM sleep.

Co-variable 2: the number of words in the corresponding dream narrative recording.

Outline the main features of the sample.

• 9 total participants

• 7 males, 2 females

• 5 were studied intensively, while 4 were studied minimally (the 4 were used to compare and confirm results)

Where did the study take place?

The sleep laboratory at the University of Chicago, USA.

Outline the procedure.

• Each participant reported to the laboratory before their usual bedtime. They were asked to avoid consuming alcohol and caffeine on the day of the experiment, but to eat normally.

• Two or more electrodes were placed near their eyes to record eye movements during sleep. Two or three electrodes were then fixed to the scalp to record brain waves so the researchers knew when a person was in REM or non-REM sleep.

• The participant was then taken to a quiet, dark room to sleep, where the wires were carefully tied at the top of the head to avoid becoming tangled in them during the night. An EEG was run throughout the night in the next room.

• Throughout the night, participants were woken at various times, in both REM and non-REM sleep, by a doorbell that was loud enough to wake them from deep sleep

• Participants were asked to first say whether they had been dreaming or not, and then to describe the content of their dream into a recording device near their bed. After this, they were able to go back to sleep.

• Occasionally, the experimenter would enter the room to question them further about an aspect of their dream.

• Participants were only considered to have been dreaming if they could recall their dream content in detail.

Outline a result in relation to aim 1.

Outline a result in relation to aim 2.

Outline the results of aim 3.

Outline the result for aim 4.

State two conclusions of the study.

1) Dreaming occurred during periods of REM sleep in distinct episodes throughout the night.

2) The researchers concluded that dreaming can be objectively measured by recording REM cycles during sleep.

Outline the generalizability of Dement and Kleitman (Sleep and dreams).

Low:

• Small sample size (9 total participants)

• Strong gender imbalance (7 males, 2 females)

• Sampled from one specific area (University of Chicago, IL, USA).

Evaluate the reliability of Dement and Kleitman.

High:

• Standardized procedure: All participants were fitted with the same equipment, (electrodes near their eyes and on their scalp), all slept in a bed in a quiet, dark room, each were woken up by a doorbell ring and were instructed to outline their dreams into a tape recorder.

Evaluate the validity of Dement and Kleitman.

Internal Validity:

High

• Controls to minimize extraneous variables;

External Validity:

Low

• Participants were sleeping in a lab with electrodes attached to their scalp and near their eyes; this could’ve distributed their natural sleep patterns and comfort

• Participants may naturally have caffeine and alcohol in their everyday diet, being told to avoid it may affect their normal sleep patterns

Evaluate the ethics followed or broken in Dement and Kleitman.

Privacy: Possibly broken, participants were forced to share dreams and that may have been personal or they do not want to answer

Had: Informed consent, right to withdraw, etc.

Evaluate the study, give 2 strengths.

High level of procedure standardization

• all participants were grounded with the same equipment with electrodes near the eyes and scalp with wires taped together behind their head

• all participants slept in the bed in a quiet dark room, and were woken by the same doorbell ring, and we’re required to narrate their dream into a tape record

Used quantitative data

• Allowed for data to be objectively analyzed

• Helps to reduce the effects of subjectivity on the interpretation of dream content (the number of words in a dream narrative was calculated and correlated with the amount of time spent in REM)

Evaluate the study, give 2 weaknesses.

Lack of ecological validity

• participant and slept with electrons attached to their head in a laboratory, making sleep, possibly uncomfortable or affecting their sleep patterns

• The avoidance of alcohol and caffeine may have affected their sleep as they additionally may have been a natural part of their sleep cycle or diet.

Variation in duration of sleep cycles between participants

• individual differences in sleeping patterns could have affected the validity of the study as the duration of dream cycles in correlation to dream content may have been increasingly different among participants

Define REM.

(Rapid eye movement) is a stage of sleep in which our eyes move rapidly underneath the lids, which is associated with vibrant and visual dreams

Define frequency and amplitude.

Frequency: the number of events, perfect period of time

• Ex. the number of five movements per minute approximately 60 per minute in REM sleep, or the number of brain waves in a certain period of time

Amplitude: the height of brain waves on an electroencephalograph

Define electroencephalograph (EEG).

A machine used to detect electrical activity in nerve and muscle cells while they are active at the same time you use macroelectrodes which are large electrodes, stuck to the skin or scalp

Outline one strength with using an EEG to investigate dreaming.

• it gives an objective measure of the participants current sleep stage. The frequency and amplitude of brain waves was able to be directly analyzed using quantitative data, making it objective rather than subjective interpretations