Chapter 5: Variations in
The Nature of Consciousness
Consciousness is awareness of internal and external stimuli.
Stream of consciousness is the fact that your consciousness is everchanging.
Mind wandering refers to peoples experience of taskunrelated thoughts.
The distinction between what we control in our mind and what just seems to happen is
known as the difference between controlled and automatic processes.
Unconscious Thought Effects
Studies show that if you have more time to think about a decision, it may not be as good
of a decision.
The difference between unconscious thought and conscious thought is attention,
conscious thought is with attention.
In conscious thought, one may not take in account every single factor or subset of
relevant info, when making an evaluation or decision. The advantage of unconscious
thought is that it doesn’t have the same capacity constraints.
Consciousness and Brain Activity
Consciousness does not arise from any specific area in the brain, but rather from activity
in distributed networks of neural pathways.
The most common indicator of variations in consciousness is the EEG. This is a device
that monitors the electrical activity of the brain over time by recording electrodes
attached to the scalp.
It outs activity in therms of line tracings, called brain waves. These vary in frequency and
There are four states of consciousness in humans, named by greek figures:
• Beta – (1324 cps) When you are problem solving.
• Alpha – (812 cps) When you are resting and relaxed.
• Theta – (47 cps) When you slip into a light sleep.
• Delta – (less than 4 cps) Biological Rhythms and Sleep
Biological Rhythms are periodic fluctuations in physiological functioning.
The Role of Circadian Rhythms
Circadian Rhythms are the 24hour cycles found in humans and many other species.
In humans, these are particularly influential in the regulation of sleep.
They also produce rhythmic variations in blood pressure, urine production, hormonal
secretions, and other physical functions, as well as shortterm memory, alertness, and
other aspects of cognitive performance.
Light levels > retina > suprachiasmatic nucleus of hypothalamus > pineal gland >
secretion of melatonin
Ignoring Circadian Rhythms
Accumulated sleep loss must be paid back hourforhour.
The Sleep and Waking Cycle
An EMG records muscular activity and tension and an EOG records eye movements.
Cycling through the Stages of Sleep
There is no obvious transition between wakefulness and sleep.
When entering sleep, muscle tension and body temperature start to decline, and breathing
and heart rate slow.
Slowwave sleep consists of sleep stages 3 and 4 suring which highamplitude, low
frequency delta waves become prominent.
People are relatively hard to awaken from it.
The most dreams occur during this stage.
Marked by rapid eye movements, highfrequency, and low amplitude brain waves and
NonREM sleep consists of stages 14 and are marked by relatively low dreaming and
varied EEG activity. Young adults typically spend about 1520% of their sleep cycle in slowwave sleep, and
another 2025% in REM sleep.
Age and Sleep
New borns sleep six to eight times in a 24 hour period, often exceeding a total of 16
hours of sleep.
The Neural Bases of Sleep
The ascending reticular activating system consists of afferent fibres running through
the reticular formation that influence psychological arousal.
Activity in the pons and the midbrain are crucial for the generation of REM sleep. The
hypothalamus plays a role in sleep and wakefulness.
Specific areas in the medulla, thalamus and the basal forebrain also play parts.
When people make do with less sleep than required over a period of time.
The effects depend on how much sleep is lost and the task at hand.
Enough NREM sleep, but no REM sleep.
Little impact on daytime functioning and task performance, but does affect patterns of
sleeping. People slip into REM sleep more and more often as the deprivation continues.
REM and slowwave sleep each promote different types of memory.
Neurogenesis is the formation of new neurons. Sleep fosters this.
Sleep loss and Health
Sleep restriction tends to trigger hormonal changes that increase hunger, an impaired
immune system, and increased inflammatory responses, which heightens vulnerability to
Short sleep duration is linked to an increased risk for diabetes, hypertension and
The most common sleep disorder. Refers to chronic problems in getting adequate sleep.
3 basic patterns:
• Difficulty falling asleep
• Difficulty remaining asleep
• Persistent earlymorning wakening
The first is most common among younger people.
Associated with daytime fatigue, impaired functioning, elevated risk for accidents,
reduced productivity, anxiety, depression, substance abuse, hypertension and increased
About 3445 percent of adults report problems with insomnia, and about half of them
experience severe or frequent insomnia.
It increases with age.
It is 50% more common in women than men.
Excessive anxiety and tension often keep people from sleeping.
Insomnia is a frequent side effect of emotional problems such as depression, or
significant stress (e.g. pressures at work).
Health problems such as back pain, ulcers and asthma can also obviously cause lack of
The use of drugs, such as stimulants like cocaine and amphetamines can also diminish
The primary cause of insomnia is that some people are predisposed to insomnia because
they have a higher level of psyshological arousal than average.
According to this hyperarousal model of insomnia, some people exibit hormonal
patterns that fuel arousal, elevated heart rate, high metabolic activation and increased
The most common is the prescription of two classes of drugs: benzodiazepine sedatives
which were originally developed to reduce anxiety, and nonbenzodiazepine sedatives
which were mainly designed for sleep probems. Both help patients fall asleep more quickly, reduce nighttime awakenings, and increase
total sleep time.
They may be used to frequently, 515 adults still use medications regularly.
They can be a poor longterm solution.
• They have carryover effects that cause drowsiness and sluggishness throughout
• Can impair their functioning
• Can cause an overdose in conjunction with alcohol or opiates
• They become less effective with continued use, and increasing dose increases
• When people abruptly discontinue taking them, withdrawal symptoms and
increased insomnia can occur
Coginitive Behavioural therapy is proven to be more successful.
Other Sleep Problems
Narcolepsy is a disease marked by sudden and irresistible onsets of sleep during normal
Sleep apnea involves frequent, reflexive gasping for air that awakens a persona nd
It is defined by the person stopping breathing for a minimum of 10 seconds, at least 5
times per hour of sleep.
Usually accompanied by loud snoring.
It increases vulnerability to hypertension, coronary disease, and stroke.
It is treated through lifestyle modifications (weight loss, sleep hygiene, and reduced
alcohol intake), drug therapy, special masks and oral devices, as well as upper
Nightmares are anxietyarousing dreams that lead to awakening, usually from REM
sleep. Can be caused by significant stress, and lack of wellbeing, or neuroticism, trait
anxiety, state anxiety, and depression.
Counselling may be helpful, but children usually outgrow the problem.
Dreams provide us with a way to discard and deal with old fearladen memories so that
we can be ready for new events and experiences in our waking life.
Night terrors are abrupt awakenings from NREM leep, accompanied by intens
autonomic arousal and feelings of panic. Victims usually let out an abrupt cry, bolt
upright, and then stare into space. Treatment is often unnecessary. Somnambulism or sleepwalking, occurs when a person arises and wanders while still
asleep. Tends to occur during the first two hours of sleep, in slowwave sleep.
May last 15 seconds to 30 minutes. It is safe to awaken sleep walking people.
REM Sleep Behaviour Disorder (RBD) is marked by troublesome dream enactments
during REM periods.
People may talk, yell, gesture, flail about or leap out of bed during dreams. They can
often hurt themselves or partners, and typically occurs to men in their 50s or 60s.
Usually people in REM are virtually paralyzed, but these people seem to have a
deterioration in the brainstem structures responsible for this paralyzation.
Has been found to coexist with other sleep disorders.
The World of Dreams
The Contents of Dreams
Tend to unfold in familiar settings with characters dominated by family, friends and
We are more tolerant of illogical discrepancies and implausible scenarios but our dreams
are mostly in coherent sensible, realistic virtual worlds.
We almost always have a sense of self, and view the world through 1 person in our
The most frequent types of dreams are of being chased or pursued, but not physically
injured, as well as sexual experiences.
Dreaming is thought to be a cognitive ability that develops gradually.
Links Between Dreams and Waking Life
The relationship of daily stress to dreams depends on factors, including the nature of the
stressor. Certain stressors such as imminent surgery may show up in dreams more often
than say, upcoming exams.
Day residue is the spillover of daily events that “spill” into the contents of our dreams.
On occasion, the content of dreams can be affected by stimuli experienced while the
person is dreaming.
For example, one may have dreams incorporating water if water is sprayed onto their
hands while sleeping, and they remain asleep.
Alarm clocks can also be incorporated into the dream in forms of a siren or loud engine
When people realize that they are dreaming while in the dream state, it is refered to as
lucid dreaming. This may be useful for the treatment of nightmares. Theories of Dreaming
Freud thought of the principle purpose of dreams is wish fulfillment.
Others propose dreams are an opportunity to overcome and wor