Chapter 5 Variations in Consciousness – Study
>The Nature of Consciousness
Consciousness: the awareness of internal and external stimuli.
-Consciousness is continuously changing, William James (stream of consciousness)
>Variations in Awareness and Control
Mind Wandering: refers to people’s experience of task- unrelated
- What we control about our mental processes and what just seems to happen
is often referred to as the difference between controlled and automatic
Controlled Processes: judgments or thoughts that we exert some control
Automatic Processes: effects happen without our intentional control or
- Malcolm Gladwell: term blink refers to how quickly (eg. In the blink of an eye)
>Consciousness and Brain Activity
- One of the best physiological indicators of variations of consciousness is the EEG.
- Different patterns of EEG activity are associated with different states of
- Human brain-wave tracings vary in amplitude (height) and frequency (cycles per
- Human brain- wave’s activity is usually divided into 4 principle bands:
1) Beta: 13-24 cps- Normal waking thought alert problem solving
2) Alpha: 8-12 cps- Deep relaxation, blank mind, meditation
3) Theta: 4-7 cps- Light sleep
4) Delta: Less than 4 cps- Deep Sleep
>Featured Study: Our Wandering Thoughts
- Examining the effects of the differences in cognitive ability on people’s experience
of their own everyday mental life, stream of consciousness.
-Examining the effects of differences in a preexistent cognitive ability on the
wandering nature of our stream of consciousness.
- The cognitive ability that was hypothesized to affect frequency of wandering
thoughts was: working memory capacity (WMC).
- WMC is assessed by giving participants a series of numbers or letters to remember
while having them perform another task at the same time. - People low in WMC would be less able to regulate their thoughts and behavior and
thus be more vulnerable to wandering thoughts or a restless mind.
Participants: Volunteers were solicited from undergraduate psychology classes. The
final sample of 126 participants included 35 males and 88 females.
Measures: Cognitive ability (WMC) was assessed by three complex memory span
measures, in which participants were presented with list of to be remembered
Procedure: The frequency of participants mind wandering was assessed for one
week using event sampling methodology. The questions that were asked to
participants were things such as whether at that moment their thoughts were
wandering from whatever they were trying/ supposed to do at that point in the day
whether they thought they had control over their thoughts at that moment and
questions about the content of their thoughts.
Results: Mind wandering was more common in certain contexts, when activities
appeared to be boring or there was a lack of interest. Less mind wandering
happened when participants were happy, felt competent, and was more involved in
>Biological Rhythms and Sleep
- REM: Rapid Eye Movement- discovered by William Dement in the 1950’s-
credited for creating the first modern scientific laboratory dedicated to sleep.
-Important links between sleep quality and the body’s natural rhythm.
-Variations in consciousness are shaped in part by biological rhythms.
-Biological Rhythm: periodic fluctuations in physiological functioning.
-Organisms have internal “biological clocks”
-Monthly: MENSTURATION/LUNAR CYCLE
-Yearly: MIGRATION/HIBERNATION (mostly animals)
-Weekly: COMMON COLD/ BEARD GROWTH
> The Role of Circadian Rhythms
- Circadian Rhythms: the 24- hour biological cycles found in humans and
many other species.
-Influential to the regulation of sleep
-Persist even when external time cues are eliminated. – When people are isolated
their cycles run a little longer than normal, about 24.2 hours on the average.
- Produce rhythmic variations in blood pressure, urine production, hormonal
secretions and other physical functions as well as alertness, short –term memory
and other aspects of cognitive performance.
- People usually fall asleep as their body temperature begins to drop and awaken
when it begins to ascend. - Circadian rhythms can leave individuals physiologically primed to fall asleep most
easily at a particular time of day.
-Sleep quality nay be more strongly correlated with health and well-being.
- Daily exposure to light readjusts people’s biological time clocks. - When exposed
to light, some receptors in the retina send direct inputs to a small structure in the
hypothalamus called the suprachiasmatic nucleus (SCN). SCN sends signals to the
nearby pineal gland, whose secretion of the hormone melatonin plays a key role in
adjusting biological clocks.
>Ignoring Circadian Rhythms
- If you get less sleep than the amount of sleep that you need, you accumulate
“sleep debt”- for this to go back to normal it must be paid back by getting extra
- Being out of sync with your circadian rhythms can cause jet lag.- It is easier to
readjust when you fly westward and lengthen your day to when you fly
eastward and shorten your day.
-Workers on rotating shifts get less total sleep and when they do get sleep it is
- Lack of sleep or poor-quality sleep can increase workers accident proneness. Shift
workers also repot more stress and a lower sense of mastery or control.
>Melatonin and Circadian Rhythm
-Studies suggest that melatonin can reduce the effects of jet lag by helping
travelers resynchronize their biological clocks.
> The Sleep and Waking Cycle
-Sleep labs have more than one “bedroom” in which subjects retire, usually after
being hooked up to a variety of physiological recording devices. – EEG, EMG
(records muscular activity and tension) and EOG (records eye movement) - There
are other instruments that monitor heart rate, breathing, pulse rate and body
- During sleep, people cycle through a series of five stages:
Stage 1: Brief transition stage of light sleep that usually last only a few (1-7)
minutes. Breathing and heart rate slow as muscle tension and body temperature
decline. (alpha waves -> theta waves)
-Hypnic Jerks : brief muscular contractions that occur as people fall asleep
occur in stage 1 drowsiness.
Stage 2: last about 10-25 minutes, brief burst of high frequency brain waves called
sleep spindles; appear against a background of mixed EEG activity. The brain waves
become higher in amplitude and slower in frequency, as the body moves into a
deeper form of sleep called slow-wave sleep. Typically individuals reach slow wave
sleep in about half an hour and stay there for roughly 30 minutes. -Slow Wave Sleep (SWS): consist of sleep stages 3 and 4 during which high
amplitude, low-frequency delta waves become prominent in EEG
REM Sleep: A relatively deep stage of sleep marked by rapid eye
movements; high-frequency, low-amplitude brain waves; and vivid
Non-REM (NREM): sleep consist of sleep stages 1 through 4, which are
marked by an absence of rapid eye movements, relatively little dreaming
and varied EEG activity.
-When sleepers reach what should be stage 1 once again, they usually go
into the fifth stage of sleep.
- The REM stage tends to be a “deep” stage of sleep in the conventional
sense that people are relatively hare to awaken from it.
-This stage is marked but irregular breathing and pulse rate. Muscle tone is
extremely relaxed- so much so that body movements are minimal and the
sleeper is visually paralyzed.
- EEG activity is dominated by high-frequency beta waves that resemble
those observed when people are alert and awake.
- People usually repeat the sleep cycle about 4 times.
- Subsequent REM periods get progressively longer, peaking at around 40-60
minutes in length.
- Slow – wave sleep occurs early in the sleep cycle and REM sleep tends to
pile up in the second half of the sleep cycle.
Age Trends in Sleep
-Age alters the sleep cycle
-Babies immediately after birth: There are only two sleep types REM and non-REM
sleep. - Newborns will sleep 6 to 8 times in a 24- hour period, often exceeding a
total of 16 hours of sleep. - Infants spend much more of their sleep time in the REM
stage than adults do. - 50% of babies sleep
-During the remainder of the first year, the REM portions of infants’ sleep declines.
- The average amount of total sleep time also declines with advancing age.
Culture and Sleep
-sleeping arrangements and napping customs
-co-sleeping: the practice of children and parents sleeping together
- In many societies, shops close and