Dement and Kleitman Study: Dream Recall, REM, and Eye Movements

What was the aim of the Dement and Kleitman study?

To investigate differences in dream recall between REM and nREM sleep, the correlation between dream duration estimates and REM length, and the relationship between eye movement patterns and dream content.

What type of experiment was conducted in the Dement and Kleitman study?

A laboratory experiment using a repeated measures design.

What was the independent variable (IV) in the study?

Whether the participant was woken from REM or nREM sleep.

What was the dependent variable (DV) in the study?

Whether the participant recalled a dream or not.

How many dreams were recalled from awakenings during REM sleep?

152 out of 191 dreams, which is 79.6%.

What percentage of participants recalled a dream when awakened from nREM sleep?

Only 6.9% (11 out of 160) recalled a dream.

What was the recall percentage for nREM awakenings within 8 minutes of REM?

29% recall of dreams.

What was the recall percentage for nREM awakenings longer than 8 minutes after REM?

Less than 5% recall.

What correlation was found between subjective dream duration estimates and the length of the REM period?

A significant positive correlation (r=0.4 to r=0.71).

What were the accuracy percentages for participants estimating dream durations of 5 and 15 minutes?

88% for 5 minutes and 78% for 15 minutes.

What was noted about the narrative descriptions of dreams for longer durations?

There was not much change in description between 5 and 15 minutes, likely due to difficulty in recalling details from longer dreams.

What method was used to wake participants in the study?

Participants were woken randomly from either REM or nREM sleep without being informed of the timing.

What did participants do immediately after waking in the study?

They stated whether they were dreaming and, if so, described their dream into a recorder.

What was the second aim of the Dement and Kleitman study?

To determine if there is a positive correlation between subjective estimates of dream duration and the length of the REM period before waking.

What was the third aim of the study regarding eye movements?

To investigate if eye-movement patterns are related to dream content.

What design was used to estimate dreaming duration in the second aim?

A repeated measures design where participants guessed how long they had been dreaming after being woken.

What was the significance of the findings regarding REM periods and narrative word counts?

There was a significant positive correlation between the length of the REM period and the number of words in the dream narrative.

What was the deception involved in the study for participant WD?

WD was told they would only be woken in REM but was actually woken in both REM and nREM stages randomly.

How were participants selected for the study?

Using a random number table to assign participants to groups.

What was the aim of the study regarding eye movement patterns and dream content?

To explore the relationship between eye movement patterns during sleep and the content of dreams.

What type of eye movements were primarily detected in the study?

Mainly vertical, mainly horizontal, and both vertical and horizontal movements.

What was the duration of the eye movement patterns observed in participants?

Participants were woken after a single eye-movement pattern lasting 1 minute.

What were some examples of vertical eye movements reported by participants?

Examples included looking up at climbers on a cliff, shooting basketballs, and climbing.

What was a notable observation regarding horizontal eye movements?

Participants reported watching two people throwing tomatoes at each other.

What did the control group in the study compare?

It compared the eye movement patterns of dreaming participants to those of participants who were not dreaming.

How does proximity to an object affect eye movement according to the study?

Closer objects resulted in more eye movement, while farther objects resulted in less eye movement.

What were the typical characteristics of dreams reported in the study?

Dreams were typically longer later in the night, lasting 3-50 minutes with a mean of 20 minutes.

What is the significance of REM sleep in relation to dreaming?

Dreaming is primarily experienced during REM sleep, and participants do not return to dreaming until they reach REM again.

What is REM rebound?

The phenomenon where the body increases time spent in REM sleep after a period of REM deprivation.

What ethical issue was raised regarding participant deception in the study?

Participants were misled about the stage of sleep they were being woken from.

What method was used to measure brain and eye activity during sleep?

EEG (electroencephalography) was used to record brain and eye activity.

What was the sample size of the study?

The study included 7 males and 2 females, with 5 studied in detail.

What are the four stages of sleep mentioned in the study?

NREM Stage 1, NREM Stage 2, NREM Stage 3, and REM sleep.

What characterizes NREM Stage 1 sleep?

It is characterized by drifting in and out of sleep, lasting only a few minutes, with light sleep and hypnic jerks.

What is the significance of NREM Stage 3 sleep?

It is the deepest stage of sleep characterized by delta waves, crucial for physical and mental restoration.

What is the relationship between eye movements and dream imagery?

Eye movements are associated with the imagery of dreaming, reflecting what the dreamer is experiencing.

What is the impact of caffeine and alcohol on the study's findings?

Participants were excluded from consuming caffeine and alcohol, as these substances could affect sleep and dreams.

What was the design of the experiment conducted in the study?

It was a laboratory experiment using a repeated measures design.

What does the term 'circadian rhythm' refer to?

The pattern of waking and sleeping on a 24-hour cycle.

What did Aserinsky and Kleitman discover about sleep stages?

They found that there are several sleep stages that fluctuate throughout the night, including REM sleep.

What is mindfulness as defined in the Hozel et al?

Increased awareness of present moments, allowing individuals to appreciate simple positive experiences.

What are some applications of the Dement and Kleitman findings?

Assessing people with sleep and dream disorders such as insomnia, nightmares, and sleepwalking.

What is the primary aim of the Hozel et al using MRI?

To identify changes in specific brain regions and the whole brain by comparing grey matter before and after a mindfulness course.

What type of study design was used in this Hozel et al?

A longitudinal design.

What was the dependent variable (DV) measured in the Hozel et al?

Change in grey matter assessed using MRI scans.

What mindfulness techniques were included in the intervention?

Body scan, mindful yoga, and sitting meditation.

What was the average age of participants in the experimental group?

38 years.

What significant changes were detected in the experimental group?

Increased grey matter in the left hippocampus and other brain regions.

What was the average time participants spent on mindfulness homework?

Approximately 27 minutes per day.

What were the results regarding grey matter changes in the control group?

The control group showed small reductions in grey matter.

What ethical considerations were addressed in the Hozel et al?

Participants were screened for mental implants or claustrophobia, and they had the right to withdraw.

What is the Five Facet Mindfulness Questionnaire (FFMQ)?

A tool measuring observing, describing, acting with awareness, non-judging, and non-reacting.

What is the significance of the temporal parietal junction (TPJ) in this study?

It is important for self-perception and noticing internal and external stimuli.

What did the study conclude about mindfulness and brain structure?

Participation in mindfulness courses can increase grey matter in specific brain regions.

What was the sample size of the experimental group?

Initially 18 participants, reduced to 26 after two males left.

What was the control group's average age?

39 years.

What were the strengths of the Hozel et al?

Longitudinal design, control group for comparison, and objective MRI data.

What weaknesses were identified in the Hozel et al?

Interpretation of MRI data is less objective, and no correlation was found between mindfulness homework and grey matter changes.

What does the Hozel et al suggest about the relationship between nature and nurture?

It highlights a biological focus on brain structure (nature) while showing that experiences like MBSR can change brain structure (nurture).

What is the role of the cerebellum in the context of this study?

Areas affected in the cerebellum are involved in regulating emotions and healthy psychological functioning.

What was the purpose of the control group in this Hozel et al?

To ensure that changes in the experimental group were not simply due to the passage of time.

What type of data did MRI provide in this Hozel et al?

Quantitative data for statistical analysis of grey matter changes.

What is the significance of the posterior cingulate cortex in the findings?

It is involved in processing self-referential thoughts and recalling past experiences.

What was the recruitment criteria for participants in the Hozel et al?

Participants had to be physically and psychologically healthy, not on medication, and have limited meditation experience.

What is the importance of mindfulness-based stress reduction (MBSR) in this study?

MBSR is the intervention that was tested for its effects on brain structure.

What does the study imply about the impact of mindfulness on psychological health?

Mindfulness practices can enhance psychological well-being by altering brain structure.

What was the independent variable in the Hassett et al.?

The independent variable was gender (male or female).

What types of toys were used in the Hassett et al.?

The toys were categorized as traditional 'boys toys' (wheeled toys) and traditional 'girls toys' (plush toys).

How many male and female rhesus monkeys were observed in the Hassett et al.?

21 males and 61 females were observed.

What was the housing environment for the monkeys?

The monkeys were housed in a 25x25 meter outdoor area with access to a temperature-controlled indoor environment.

What was the duration of each trial in the Hassett et al.?

Each trial lasted 25 minutes.

How were the toys positioned during the trials?

One plush and one wheeled toy were placed 10 meters apart in the outdoor enclosure.

What method was used to observe the monkeys' interactions with the toys?

Two video cameras recorded the monkeys' interactions with the toys.

What behaviors were coded during the observation?

Behaviors included extended touch, hold, sit on, carry in hand, carry in arm, drag, manipulate part, turn the entire toy, touch, sniff, mouth, destroy, jump away, and throw.

What were the findings regarding male monkeys' preferences for toys?

Male monkeys showed a strong preference for wheeled toys over plush toys, with a preference rate of 73% for wheeled toys.

How did female monkeys' toy preferences compare to males'?

Females interacted with plush toys more than males, but did not show a preference for plush over wheeled toys, spending similar time on both.

What statistical analysis was performed in the Hassett et al.?

The analysis compared the frequency and duration of interactions with wheeled and plush toys between genders.

What conclusion was drawn about gender differences in toy preferences?

The study concluded that male monkeys, like boys, have a strong preference for masculine toys, while female monkeys, like girls, have more variable preferences.

What ethical guidelines were followed in the Hassett et al.?

The study adhered to ethical guidelines approved by Emory University's ethical committee, ensuring proper housing and care for the monkeys.

What was a significant strength of the Hassett et al.?

The use of animals helped eliminate the effects of socialization on toy preferences.

What was a notable weakness of the Hassett et al.?

Differences in how monkeys and children were compared, including the types of toys and methods of measuring play duration.

What does the Hassett et al. suggest about the nature vs. nurture debate?

The study suggests that biological factors, such as sex hormones, play a significant role in toy preferences, indicating an enduring influence of nature.

What application does the Hassett et al. have for gender socialization?

It stresses the need for gender-neutral socialization to allow individuals to access all opportunities and reduce gender divides.

What was the sample size of the larger group of monkeys at the research center?

The larger group consisted of 135 monkeys.

What were the two categories of toys used in the Hassett et al.?

The two categories were wheeled toys and plush toys.

What was the preference rate for plush toys among male monkeys?

The preference for plush toys among male monkeys was 9%.

What did the study reveal about the interaction duration for female monkeys?

Female monkeys spent a similar amount of time interacting with both plush and wheeled toys.

What was the preference rate for wheeled toys among female monkeys?

The preference for wheeled toys among female monkeys was 39%.

How was social rank assessed in the Hassett et al.?

Social rank was assessed through behavioral observations, such as grooming and dominant behavior.

What was the significance of the toy destruction incident during the Hassett et al.?

One toy was destroyed, but it was unclear if this was a playful act or a sign of distress.