Study

• Background

  Aserinksy and Kleitman: (1953) discovered; DIFFICULT TO TEST*

  -observed periods of REM during sleep associated with visual, vivid imagery of dreams

  -high incidence of dream recall in participants awakened during REM

  -alpha waves, other muscles in body inactive (frequency of eye movements); happens simultaneously 90 min cycle

  
  

  -compared eye movements to EOG records

  -increase in breathing/heart rates during REM

  
  

  -REM appeared at regular intervals in relation to a cyclic change in depth of sleep during night as measured by EEG
• Aims

  1 Does dream recall differ between eye movement (REM) and quiescent (nREM) stages of sleep (Did you have a dream?)

  
  

  2 Is there a positive correlation between subjective estimates of dream duration and the length of the REM period before waking (How long was I dreaming for? 5 or 15 minutes)

  
  

  3 If eye movement patterns are related to dream content (EOG: Vertical vs Hor movement/dream content)
• Research method

  -conducted in labratory, but several methods were used

  
  

  Aim 1 (difference in dream recall): repeated measures design

  
  

  Aim 2 (relation betw dream duration and length of REM pd): correlational design, had been dreaming for 5/15 minutes repeated measures

  
  

  Aim 3 (relation betw eye movement patterns and dream content): self reports compared direction of eye movements observed
• Variables

  Aim 1: (dream recall)

  IV: woken in REM or nREM

  DV: whether they recalled the dream or not

  
  

  Aim 2: (dream duration/length REM pd)

  IV: dream duration, 5/15 minutes

  DV: correct number of dream estimates

  
  

  Aim 3: (eye movement/content)

  IV: direction of eye movements

  DV: participant subjective report of dreaming
• Sample

  9 participants, 7 males and 2 females

  -2 left after the first night, 2 chose not to continue second night

  5 participants studied in detail (6-17 nights each)

  -results from remaining four participants used to confirm results of first five

  (Sample method unknown, not mentioned)
• Procedure 


  -ate normally, no alcohol or caffine (controls)

  -arrived at lab just before normal bedtime (natural)

  -quiet/darkened room, electrodes (EEG) attached beside eyes/on scalp

  -gathered into single cord to move easily

  -woken by doorbell at various times, asked to describe dream if having one

  
  

  -not told about EEG pattern/whether eyes were moving

  
  

  environment highly controlled, (doorbell sufficient, not asked any questions until participant completed recording)

  -reports not counted as dream if content wasn't remembered
• Proc Aim 1

  choice of REM/nREM waking decided based on participant

  -random number table, groups of 3

  -by telling participant only woken in REM but actually randomly

  -no specific order

  
  

  stated whether having dream, described content into recorder

  -when finished, occasionally brief interview w/ no other communication between experimenter/participant
• Proc Aim 2

  -woken variety of REM durations, initially asked to estimate had been dreaming (too difficult)

  -woken after 5/15 minutes REM then guessed which duration had been dreaming for

  -number if words in dream narrative also counted
• Proc Aim 3

  -direction of eye movements detected using EEG electrodes around eyes

  -woken after single eye-movement pattern lasted more than 1 min and asked to report their dream

  -vertical, horizontal, both, little to no eye movement
• Results

  -all participants dreamed every night; uninterrupted dream stages:

  -lasted 3-50 minutes (mean 20)

  -typically longer later in the night

  -showed intermittent bursts of around 2-100 REMs

  -nREM seen during onsent of sleep even though EEG passed through stage of brain waves similar to REM

  -cycle length varuet betw 70-104 minutes (mean 92) consistent

  -when woken from nREM, returned to nREM

  -when woken from REM, did not dream until next REM phase

  *similar when disturbed to those uninterrupted
• Results Q1

  -freq described dreams when woken from REM, rarely from nREM

  -152/191 recalled REM 79.6%

  -11 recalled nREM (149/160 no recall 93.1%)

  noticeable at end of nREM period; describe feelings not content

  (did not become more accurate over time)

  
  

  -awakenings from REM did not always produce dream recall

  -absence more common early in the night*
• Results Q2

  -out of 51 awakenings after 5 mins REM 45 est (88%) correct

  -out of 60 occasions 15 mins of REM sleep 47 est (78%) correct

  narratives from dreams recalled after 30-50minutes REM were not much longer than those after 15 minutes (not remember all details)
• Results Q3

  eye movement patterns relevant to drean content (35 awakenings)

  -pds only vertical/horizontal rare

  
  

  3 dreams vertical

  -at bottom of tall cliff operaiting a hoist and looking up at climbers then down at machine

  -climbing series of ladders looking up and down

  -throwing basketballs shooting; looking up at net, looking down to pick up another ball from the floor

  
  

  horizontal: watching 2 people throw tomatoes at each other

  10 dreams little to no eye movement

  
  

  -watching something in distance/staring at object

  -driving car staring at road ahead
• Conclusion

  -dreaming experienced in REM but not nREM

  -judge length of dream duration

  -REM patterns relate to dream content

  dreaming more likely at end of night (REM stages longer)

  
  

  -occasional recall: remembered during previous stage

  -REM sleep occurs in stages

  
  

  -measurements using EEG (eye movements/brain waves) show differing stages of brain activity

  -absence of dreams: progress in real time
• Generalizability


  -both genders represented, but small sample size limiting

  -chose to participate in study on dreaming, may have dreamed more frequently/remembered than pop in general
• Reliability


  laboratory experiment: limit uncontrolled variables (doorbell waking, not told about EEG pattern); has controls + could be retested

  -eliminate potential for demand characteristics: expected to remember more detailed dreams in REM

  
  

  -EEG provides a reliable measure bc it is unaffected by experimenters personal view

  -placing of electrodes ensured recordings from each par. provide same info
• Strengths

  -correlational design dem positive correlation betw REM duration and # of words in dream narrative (link between variables)
• Validity

  -raised as it reduced participant variables such as differences in ability to recall dreams (changed to 5/15 min after too difficult)

  -definition of 'dream' operationalized as recollection included content rather than impression of dreaming

  -ensure details rec were of dreams

  
  

  Ecological validity: people used to drinking coffee/alc could have experienced sleep/dreams not typical from them

  -sleeping in laboratory, connected to machines (unnatural)
• Weaknesses

  -EEG objective way to investigate dreaming

  -differences in narrative length make it subjective

  means it collected both quantitative (number of words) and qualitative (descriptions/actions in dream) data

  -insight on reason eye movements detected
• Ethics


  -deception of participant WD misled about stage of sleep woken in (should avoid using can cause disress and cannot give their informed consent)

  -aim cannot be achieved without doing so

  -confidentiality of names were kept private by only using initials