• Narcolepsy, a serious sleep disorder in which those who suffer from it often
fall asleep uncontrollably during their everyday routine.
• Sleep deprivation has been linked to a variety of negative outcomes, including
increasing the chances of experiencing a fatal car crash, and things such as
immune regulation impairment and metabolic control
The nature of consciousness
• Consciousness is the awareness of internal and external stimuli. As you
read this sentence, it becomes part of your consciousness
• Your consciousness is continuously changing, a fact that led William James
(1902) to describe this continuous flow as the stream of consciousness.
Some of the thoughts entering your stream of consciousness are the result of
intention: We seem to be easily able to shift our attention to things of
importance or interest in our environment
• almost every human behavior comes from a mixture of conscious and
• While attention and consciousness are clearly closely related, they are not
identical, you can have either one without the other. While some of what
enters our consciousness seems intentional and designed to further specific
goals or motivations—for example, your tendency to listen carefully to what
your professor has to say in class, especially as the exam draws closer—
other thoughts seem to just meander into our minds
• Mind wandering refers to people's experience of task-unrelated thoughts,
thoughts that are not related to what they are intentionally trying to do at a
• controlled processes—judgments or thoughts that we exert some control
over, that we intend to occur—automatic processing and its effects happen
without our intentional control or effort.
• -Conscious thought is thought with attention; unconscious thought is thought
without attention (or with attention directed elsewhere)‖
• -Conscious thought is constrained by capacity limitations such that you often
consider only a small subset of all the relevant information when making a
decision or evaluation. The advantage of unconscious thought is that it does
not have the same capacity constraint.
• The electroencephalograph (EEG) is a device that monitors the electrical
activity of the brain over time by means of recording electrodes attached to
the surface of the scalp. Ultimately, the EEG summarizes the rhythm of
cortical activity in the brain in terms of line tracings called brain waves. These
brain-wave tracings vary in amplitude (height) and frequency (cycles per
second, abbreviated cps). Human brain-wave activity is usually divided into
four principal bands, based on the frequency of the brain waves. These
bands, named after letters in the Greek alphabet, are: TABLE 5.1 EEG Patterns Associated with States of Consciousness
EEG Pattern Frequency (cps) Typical States of Consciousness
Beta (β) 13–24 Normal waking thought, alert problem solving
Alpha (α) 8–12 Deep relaxation, blank mind, meditation
Theta (θ) 4–7 Light sleep
Delta (Δ) Less than 4 Deep sleep
Different patterns of EEG activity are associated with different states of
consciousness. Consciousness involves varied levels of awareness.
Mental processes continue during sleep, as some stimuli can penetrate
Research suggests that decisions made when people do not have the chance
to make conscious deliberations may sometimes be more accurate.
The evolutionary significance of consciousness is a matter of debate.
Changes in consciousness are correlated with changes in brain activity as
measured by EEGs.
Relations to sleep
-Humans, many other animals, and even plants display biological rhythms
that are tied to these planetary rhythms. Biological rhythms are periodic
fluctuations in physiological functioning. The existence of these rhythms
means that organisms have internal ―biological clocks‖ that somehow monitor
the passage of time.
Circadian rhythms are the 24-hour biological cycles found in humans and
many other species. In humans, circadian rhythms are particularly influential
in the regulation of sleep. However, daily cycles also produce rhythmic
variations in blood pressure, urine production, hormonal secretions, and other
circadian rhythms can leave individuals physiologically primed to fall asleep
most easily at a particular time of day
circadian rhythms generally persist even when external time cues are
daily exposure to light readjusts people's biological 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). The SCN sends
signals to the nearby pineal gland, whose secretion of the hormone melatonin
plays a key role in adjusting biological clocks.
If you get less than the amount of sleep that you need, you accumulate ―sleep
a rough rule of thumb for jet lag is that the readjustment process takes about
a day for each time zone crossed when you fly eastward, and about two-
thirds of a day per time zone when you fly westward melatonin can reduce the
effects of jet lag by helping travellers resynchronize their biological clocks, but
the research results are inconsistent.
If you are a shift worker, then you know it can have important effects on you.
Studies show that workers get less total sleep when they go on rotating shifts. Researchers have also tried carefully timed exposure to bright light as a
treatment to realign the circadian rhythms of rotating shift workers in industrial
The architecture of sleep
electromyograph (EMG), which records muscular activity and tension, and
an electrooculograph (EOG), which records eye movements
Non-REM sleep consists of stages 1–4, which are marked by an absence of
rapid eye movements, relatively little dreaming, and varied EEG activity.
o onset of sleep is gradual, no obvious transition.
o Length of time it takes people to fall asleep varies considerably which
depends on fators including, how long it has been since person has
slept, circardian cycle, noise or light, persons age, desire to fall asleep,
boredom, caffeine or drug intake and stress level.
o stage 1 is a brief transitional stage of light sleep, last a few (1-7)
minutes. Breathing and heart rate slow, body temp declines.
o Give way to lower frequency EEG activity in which Theta waves are
o Hypnotic jerks are brief muscle contractions that occur when people
fall asleep and generally occur during stage 1 drowsiness.
o Respiration rate, heart rate, muscle tension, and body temperature
continue to decline. During stage 2, which typically lasts about 10–25
minutes, brief bursts of higher-frequency brain waves, called sleep
o Slow-wave sleep (SWS) consists of sleep stages 3 and 4, during
which high-amplitude, low-frequency delta waves become prominent
in EEG recordings.
o Typically, individuals reach slow-wave sleep in about half an hour and
stay there for roughly 30 minutes. Then the cycle reverses itself and
the sleeper gradually moves back upward through the lighter stages.
o When sleepers reach what should be stage 1 once again, they usually
go into the fifth stage of sleep, which is most widely known as REM
sleep. As we have seen, REM is an abbreviation for the rapid eye
movements prominent during this stage of sleep
o The REM stage tends to be a ―deep‖ stage of sleep in the conventional
sense that people are relatively hard to awaken from it
o marked by irregular breathing and pulse rate. Muscle tone is extremely
o Although REM is a relatively deep stage of sleep, EEG activity is
dominated by high-frequency beta waves that resemble those
observed when people are alert and awake
o during the course of sleep, REM periods gradually get longer and non-
REM periods get shorter and shallower. o The architecture of sleep varies somewhat from one person to the
o most dream reports come from the REM stage, REM dreams may be
more frequent, vivid, and memorable.
Sleep cycle is repeated about 4 times, the 1 REM period is relatively short,
lasting only a few minutes. Subsequent REM periods get progressively
longer, peaking at around 40-60 minutes in length. Additionally, NREM
intervals stages tend to get shorter and descents into NREM stages usually
Age alters sleep cycle. Babies immediately after birth have only 2 sleep types:
REM and non-REM sleep. They spend more time in REM than adults do.
REM portion of sleep continues to decrease gradually with age until it levels
off at about 20%. Avg amount of total sleep time also declines with advancing
Cultural disparities in sleep are limited to more peripheral matters such as
sleeping arrangements and napping customs. (siesta, avoiding work during
the hottest part of the day)
Arousal depends on activity in the Ascending reticular activating system,
but a constellation of brain structure and neurotransmitters contribute of
regulation of the sleep and waking cycle.
Partial deprivation is common and can impair alertness; it appears to
contribute to many accidents.
Selective deprivation of REM and slow wave sleep leads to increased
attempts to shift into these stages of sleep an increased time spent in these
stages after sleep deprivation ends. Also known as ‗rebound effect’.
Recent studies suggest that REM and slow-wave sleep help firm up learning
that takes place during the day—a process called ―memory consolidation‖.
REM may foster neurogenesis (formation of new neurons)
Short sleep duration is associated with a variety of health problems, but both
short and long sleepers exhibit elevated mortality rates.
Insomnia occurs in three patterns: difficulty falling asleep, difficulty remaining
asleep, and persistent early morning awakenings.
associated with daytime fatigue, impaired functioning, and elevated risk for
accidents, reduced productivity, absenteeism at work, depression, anxiety,
substance abuse, hypertension, and increased health problems
―pseudo-insomnia’ OR sleep state misperception, which means that they
just think they are getting an inadequate amount of sleep
Insomnia is a fairly common sleep disorder and it has many diverse causes
including the possibility that insomniacs have a higher arousal level,
excessive anxiety, emotional problems like depression and stress, physical
helth problems like back pain, ulcers, asthma.
Sedative drugs are a poor long-term solution to insomnia because of the risk
of overdose, escalating dependency, and carryover drowsiness. Other sleep problems
Narcolepsy is a disease marked by sudden and irresistible onsets of sleep
during normal waking periods.
Sleep apnea involves frequent, reflexive gasping for air that awakens a
person and disrupts sleep. Some victims are awakened from their sleep
hundreds of times a night. Apnea occurs when a person literally stops
breathing for a minimum of ten seconds
Nightmares are anxiety-arousing dreams that lead to awakening, usually
from REM sleep (see Figure 5.10). Typically, a person who awakens from a
nightmare recalls a vivid dream and may have difficulty getting back to sleep.
10 percent of adults have occasional nightmares; these frightening episodes
are mainly a problem among children. Most youngsters have occasional
nightmares, but persistent nightmares may reflect an emotional disturbance.
Night terrors (also called ―sleep terrors‖) are abrupt awakenings from NREM
sleep, accompanied by intense autonomic arousal and feelings of panic.
Victims typically let out a piercing cry, bolt upright, and then stare into space.
They do not usually recall a coherent dream, although they may remember a
simple, frightening image. The panic normally fades quickly, and a return to
sleep is fairly easy. Night terrors occur in adults, but they are especially
common in children aged three to eight.
Somnambulism , or sleepwalking, occurs when a person arises and wanders
about while remaining asleep. Sleepwalking tends to occur during the first two
hours of sleep, when individuals are in slow-wave sleep (see Figure 5.10).
Episodes may last from 15 seconds to 30 minutes
REM sleep behaviour disorder (RBD) is marked by potentially troublesome
dream enactments during REM periods. People who exhibit this syndrome
may talk, yell, gesture, flail about, or leap out of bed during their REM
The nature of dreams
Dreams are mental experiences during REM sleep that have a story-like
quality, include vivid visual imagery, are often bizarre, and are regarded as
perceptually real by the dreamer. They tend to unfold in familiar settings
with a cast of characters dominated by family, friends, and colleagues. We
are more tolerant of logical discrepancies and implausible scenarios in our
dreams than our waking thought
The one nearly universal element of dreams is a coherent sense of self—
we almost always experience dreams from a first-person perspective.
incorporation of external stimuli into dreams shows that people's dream
world is not entirely separate from their real world.
Sometimes people may realize they are dreaming while still in the dream
state. These are often referred to as ―lucid dreams‖. In some of these
dreams, the dreamer may be able to exert some control over the dream.
Cultural variations are seen in dream recall, dream content, dream
interpretation, and the importance attributed to dreams. The World of Dreams
Theories of dreaming
Sigmund Freud asserted that the chief purpose of dreams is wish
fulfillment. For example, someone who is sexually frustrated might have
highly erotic dreams
Cartwright articulated a Cognitive, problem-solving view; there is
considerable continuity between waking and sleeping thought. Proponents
of this view believe that dreams allow people to engage in creative
thinking about problems because dreams are not restrained by logic or
Hobson and McCarley assert The activation–synthesis model proposes
that dreams are side effects of the neural activation that produces waking-
like brain waves during REM sleep. According to this model, neurons firing
periodically in lower brain centres send random signals to the cortex
Hypnotic induction and phenomena
Hypnosis is a procedure that produces a heightened state of
suggestibility. People vary in their susceptibility to hypnosis.
Hypnotic susceptibility is a stable trait made up of three components:
o Absorption involves the capacity to reduce or block peripheral
awareness and narrow the focus of one's attention.
o Dissociation involves the ability to separate aspects of perception,
memory, or identity, from the mainstream of conscious awareness.
o Suggestibility involves the tendency to accept directions and
information relatively uncritically.
Hypnosis can produce a variety of effects, including:
o anesthesia (Under the influence of hypnosis, some participants
can withstand treatments that would normally cause considerable
o sensory distortions and hallucinations,
o disinhibition (sometimes reduce inhibitions that would normally
prevent subjects from acting in ways that they would see as socially
o posthypnotic amnesia (Such subjects usually claim to remember
nothing, as ordered. However, when pressed, many of these
subjects acknowledge that they have not really forgotten the
Theories of hypnosis
According to Theodore Barber, hypnosis produces a normal state of
consciousness in which people act out the role of hypnotized subject.
The role-playing view is supported by evidence that hypnotic feats can be
duplicated by nonhypnotized subjects and that hypnotic subjects are often
acting out a role.
According to Ernest Hilgard, hypnosis produces an altered state of awareness characterized by dissociation. The altered state view is
supported by evidence that divided consciousness is a common state
that has continuity with everyday experience. Ex. people will often drive a
car a great distance, responding to traffic signals and other cars, with no
recollection of having consciously done so.
Physiological correlates and long-term benefits
Meditation refers to a family of practices that train attention to heighten
awareness and bring mental processes under greater voluntary control.
Two types of mediation are:
o focused attention (attention is concentrated on a specific object,
image, sound, or bodily sensation (such as breathing) meant to reduce
clutter of the mind) and
o open monitoring (attention is directed to the contents of one's
moment-to-moment experience in a nonjudgmental and nonreactive
Studies suggest that effective meditation leads to a beneficial physiological
state that may be accompanied by changes in brain activity. alpha waves and
theta waves become more prominent in EEG recordings, Many studies also
find that subjects‘ heart rate, skin conductance, respiration rate, oxygen
consumption, and carbon dioxide elimination decline. Suppression of body
Evidence suggests that meditation may reduce stress hormones, enhance
self-esteem and well-being, and reduce vulnerability to a variety of diseases.
Recent work highlights the efficacy of cognitive-behavioural therapy rooted in
mindfulness meditation. Some critics suggest that these benefits may not be
unique to meditation and are a product of relaxation.
Altering Consciousness with Drugs
Factors influencing drug effects
The drugs that people use recreationally are psychoactive. Psychoactive
drugs are chemical substances that modify mental, emotional, or behavioural
functioning. Not all psychoactive drugs produce effects that lead to
recreational use. Generally, people prefer drugs that elevate their mood or
produce other pleasurable alterations in consciousness.
Drug effects depend on users‘ age, mood, personality,weight, expectations,
and previous experience with drugs. Drug effects also depend on the potency
of the drug, the method of administration, and the user‘s tolerance.
Risks associated with drug abuse
Physical dependence exists when drug use must be continued to avoid
Psychological dependence exists when drug use must be continued to
satisfy craving for the drug.
Many drugs, especially CNS depressants, can produce a lethal overdose.
Drugs cause direct tissue damage, snorting cocaine can damage nasal
The negative effects of drugs on physical health are often due to indirect behavioural effects, attitudes and intentions. Ex. Not eating or sleeping
Principal abused drugs
Narcotics are drugs derived from opium, such as heroin.
Sedatives are sleep-inducing drugs and tend to decrease CNS acitivation
and behavioural activity , such as barbiturates.
Stimulants are drugs that increase CNS activation, such as cocaine and
Hallucinogens, such as LSD and mescaline, produce sensory distortions
and diverse mental and emotional effects.
Cannabis is the hemp plant from which marijuana, hashish, and THC are
Alcohol includes a variety of beverages that contain ethyl alcohol.
MDMA (ecstasy) is a compound drug related to amphetamines and
Mechanisms of drug action
Psychoactive drugs exert their effects by selectively altering neurotransmitter
o Increased activation in the mesolimbic dopamine pathway may be
responsible for the reinforcing effects of many drugs.
learning is any relatively durable change in behaviour or knowledge that is
due to experience.
Phobias are irrational fears of specific objects or situations and are often the
result of another learning process termed classical conditioning. Classical
conditioning often plays a key role in shaping emotional responses such as
The principles that explain learned responses in animals explain much of
human learning, too Conditioning involves learning connections between
events that occur in an organism's environment
Classical conditioning is a type of learning in which a stimulus acquires the
capacity to evoke are sponse that was originally evoked by another stimulus.
The process was first described around 1900 by Ivan Pavlov. His work
showed how stimuli in the external world controlled our actions and behaviour
(Pickren & Rutherford, 2010). He de-emphasized the mind, and mentalistic
accounts of behaviour, and showed how learning was under the influence of
experience and that ―associations could be built up in consciousness‖
unconditioned stimulus (UCS) is a stimulus that evokes an unconditioned
response without previous conditioning.
unconditioned response (UCR) is an unlearned reaction to an
unconditioned stimulus that occurs without previous conditioning.
conditioned stimulus (CS) is a previously neutral stimulus that has, through
conditioning, acquired the capacity to evoke a conditioned response. conditioned response (CR) is a learned reaction to a conditioned stimulus
that occurs because of previous conditioning.
trial in classical conditioning consists of any presentation of a stimulus or
pair of stimuli.
Evaluative conditioning refers to changes in the liking of a stimulus that
result from pairing that stimulus with other positive or negative stimuli. In other
words, evaluative conditioning involves the acquisition of likes and dislikes, or
preferences, through classical conditioning. advertising campaigns routinely
try to take advantage of evaluative conditioning
Classically conditioned responses are said to be elicited. Many kinds of
everyday responses are regulated through classical conditioning, including
phobias, mild fears, and pleasant emotional responses. Even subtle
physiological responses such as immune system functioning respond to
classical conditioning. Sexual arousal can be influenced by Pavlovian
conditioning, and this process may have adaptive significance.
Compensatory CRs: In classical conditioning, a conditional response that
opposes, rather than being the same as, the unconditional response. It
functions to reduce the strength of the unconditional response, as in drug
tolerance. They partially compensate for some drug effects and help to
maintain homeostasis by canceling out anticipated effects of abused drugs.
However if drugs taken in new ways/settings, the usual compensatory CRs
may not occur and drugs may have a stronger impact.
Acquisition refers to the initial stage of learning something. Pavlov theorized
that the acquisition of a conditioned response depends on stimulus contiguity.
Stimuli are contiguous if they occur together in time and space. Evidence
suggests that stimuli that are novel, unusual, or especially intense have more
potential to become CSs than routine stimuli, probably because they are more
likely to stand out among other stimuli
extinction , the gradual weakening and disappearance of a conditioned
response tendency. What leads to extinction in classical conditioning? The
consistent presentation of the conditioned stimulus alone, without the
unconditioned stimulus. Some conditioned responses extinguish quickly,
while others are difficult to weaken.
Spontaneous recovery is the reappearance of an extinguished response after
a period of nonexposure to the conditioned stimulus.
renewal effect —if a response is extinguished in a different environment than
it was acquired, the extinguished response will reappear if the animal is
returned to the original environment where acquisition took place. extinction
somehow suppresses a conditioned response rather than erasing a learned
association. extinction does not appear to lead to unlearning
Stimulus generalization occurs when an organism that has learned a
response to a specific stimulus responds in the same way to new stimuli that
are similar to the original stimulus. The more similar new stimuli are to the
original CS, the greater the generalization.
Stimulus discrimination occurs when an organism that has learned a
response to a specific stimulus does not respond in the same way to new stimuli that are similar to the original stimulus. The less similar new stimuli are
to the original CS, the greater the likelihood (and ease) of discrimination.
higher-order conditioning , in which a conditioned stimulus functions as if it
were an unconditioned stimulus. In higher-order conditioning, new
conditioned responses are built on the foundation of already-established
operant conditioning is a form of learning in which responses come to be
controlled by their consequences. governed voluntary responses. Another
name for operant conditioning is instrumental learning . this kind of
responding is often instrumental in obtaining some desired outcome.
law of effect , if a response in the presence of a stimulus leads to satisfying
effects, the association between the stimulus and the response is
strengthened. successful responses are gradually ―stamped in‖ by their
Skinner demonstrated that organisms tend to repeat those responses that are
followed by favourable consequences. Reinforcement occurs when an event
following a response increases an organism's tendency to make that
response. In other words, a response is strengthened because it leads to
operant chamber that has come to be better known as a ―Skinner box.‖ An
operant chamber , or Skinner box , is a small enclosure in which an animal
can make a specific response that is recorded while the consequences of the
response are systematically controlled. operant responses tend to be
voluntary, they are said to be emitted rather than elicited. To emit means to
Reinforcement contingencies are the circumstances or rules that determine
whether responses lead to the presentation of reinforcers.. Ex. Food serves
as a reinforcer for mice.
The cumulative recorder creates a graphic record of responding and
reinforcement in a Skinner box as a function of time. A rapid response rate
produces a steep slope, whereas a slow response rate produces a shallow
slope. Because the response record is cumulative, the line never goes down.
It can only go up as more responses are made or flatten out if the response
rate slows to zero.
shaping , which consists of the reinforcement of closer and closer
approximations of a desired response. The mechanism of shaping is the key
to training animals to perform impressive tricks.
Extinction refers to the gradual weakening and disappearance of a response
tendency because the response is no longer followed by a reinforcer.
Resistance to extinction occurs when an organism continues to make a
response after delivery of the reinforcer has been terminated. The greater the
resistance to extinction, the longer the responding will continue. People often
want to strengthen a response in such a way that it will be relatively resistant
to extinction. For instance, most parents want to see their child's studying
response survive even if the child hits a rocky stretch when studying doesn't
lead to reinforcement (good grades). renewal effect—if a response is extinguished in a different environment than
it was acquired, the extinguished response will reappear if the animal is
returned to the original environment where acquisition took place.
Discriminative stimuli are cues that influence operant behaviour by indicating
the probable consequences (reinforcement or nonreinforcement) of a
response. For example, birds learn that hunting for worms is likely to be
reinforced after a rain.
Reactions to a discriminative stimulus are governed by the processes of stimulus
generalization and stimulus discrimination, just like reactions to a CS in classical
TABLE 6.1 Comparison of Basic Processes in Classical and Operant
Process and Description in Description in Operant Conditioning
Acquisition: CS and UCS Responding gradually increases because of
The initial are paired, reinforcement, possibly through shaping.
stage of gradually
learning resulting in CR.
Extinction: CS is presented Responding gradually slows and stops after
The gradual alone until it no reinforcement is terminated.
weakening and longer elicits
Stimulus CR is elicited by Responding increases in the presence of
generalization: new stimulus