Download stimulates the release of dopamine at low doses. At higher doses it

Methylenedioxymethamphetamine (MDMA, or “ecstasy”)
stimulates the release of dopamine at low doses. At
higher doses it also stimulates serotonin synapses,
producing hallucinogenic effects similar to those of LSD.
Unfortunately MDMA not only stimulates axons that
release dopamine and serotonin, it also destroys them.
For years investigators could not explain the
effects of marijuana on the brain. When they
finally localized specific receptors for cannabinoids.
Those receptors are abundant in the hippocampus,
the basal ganglia, and the cerebellum. However,
they are virtually absent from the medulla and the
rest of the brain steam. That absence is significant
because the medulla and brain stem include the
centers that control breathing and heartbeat; we
begin to understand why even large doses of
marijuana do not threaten breathing or heartbeat.
Cannabis
vMarijuana consists of the dried leaves & flowering tops of
the cannabis plant
vLaughter, grandiosity, lethargy, impairment in short-term
memory, impaired judgment, & distorted sensory perception &
time perception
vFound to suppress the production of male hormones,
degrease the size and weight of the prostate gland and testes
& inhibit the production of sperm in males
vHelpful in controlling nausea from chemotherapy & can help
treat glaucoma
Cannabinoids dissolve in the body’s fats and leave the
body very slowly. One consequence is that users seldom
experience strong withdrawal effects after quitting the
drug, as cocaine and opiate users do.
Marijuana users do not typically overdose as cocaine and
opiate users do; even an unusually large dose of marijuana
is unlikely to interfere with breathing and heartbeat.
Barbiturates &
Tranquilizers
vDepressing effect
vCan cause an initial feeling of excitement followed by slurred
speech, loss of coordination, severe depression, and
impairment of thinking and memory
vTranquilizers are prescribed to reduce anxiety
If you or people you know have ever taken tranquilizers,
antidepressants, or other drugs, you may have noticed
that the effectiveness and side effects vary from one
person to another. Part of the explanation is that each
drug affects several kinds of synapse. For example,
antipsychotic drugs block mostly dopamine receptor but
also have smaller effects on other kinds of receptors, with
different behavioral effects.
Caffeine, a drug found in coffee, tea, and many soft
drinks, affects brain functioning in at least two ways.
First, it increases heart rate but also constricts the
blood vessels in the brain, thereby decreasing its
blood supply. Second, caffeine interferes with the
effects of the neurotransmitter adenosine.
Drugs that distort perception are called hallucinogenic
drugs. Many hallucinogenic drugs, such as lysergic
acid diethylamide (LSD), chemically resemble
serotonin and stimulate serotonin type 2 (5­HT2)
receptors at inappropriate times or for longer than
usual durations.
Note that we know where in the brain LSD exerts its
effects, but not why those effects include
hallucinations and other changes in perception.
Hallucinogens
vAlter one‛s conscious so that perceptions are
distorted
vUsed for religious purposes
vFlash backs are post-hallucinogen perceptual
disorder
Methylphenidate (Ritalin), another stimulant drug, is often
prescribed for people with attention­deficit disorder (ADD),
a condition marked by impulsiveness and poor control of
attention. Methylphenidate and cocaine both block the
reuptake of dopamine at the same receptors in the brain.
However, when people take a methylphenidate pill, its
concentration in the brain increases gradually over an hour
and then declines with a half­life of more than an hour and a
half, in contrast to cocaine, which produces a four to five
times faster rise and fall of effects.
Nicotine
vStimulates certain neurotransmitters which exert powerful
effects on the brain and spinal cord, the peripheral nervous
system and the heart
vCan cause heart attacks, reduced weight of babies, and lung
cancer
vThere are psychological and physiological effects of a
person trying to quit
vKicking the habit has been equated to trying to kick heroin
Nicotine, a compound present in tobacco, has long been
known to stimulate one type of acetylcholine receptor.
Phencyclidine (PCP or “angel dust”) is a commonly abused
drug that, at low doses, produces intoxication and slurred
speech, somewhat like the effects of alcohol. Larger doses
produce hallucinations, thought disorders, loss of emotion,
and memory loss.
PCP is an apparent exception
to the rule that abused drugs
increase activity at dopamine
synapses.
Substance Dependence
•Exhibit a maladaptive pattern of substance
use that leads to clinically significant
impairment or distress
•Affected cognitively, behaviorally, & physiologically
•Tolerance for the substance is usually experienced
•Withdrawal symptoms ranging from mild to severe when the
substance is withdrawn
•Compulsive substance use – the substance becomes one‛s
primary focus
Substance Abuse
vDo not exhibit symptoms of tolerance, withdrawal, or
compulsive substance use, but they have shown significant
negative reactions & behaviors due to their substance use
vThere has been a great deal of argument regarding the
distinction between substance abuse & dependence
Substance-Induced Disorders
vBehavioral, psychological, & physiological
symptoms can follow the recent ingestion of
certain substances in a condition known as
substance intoxication
vDelirium and psychotic behavior are
symptoms of a substance-induced disorders
which mirror symptoms of other mental
disorders
The evolutionary perspective reminds us
that consciousness must be highly adaptive
for it to have become such a prominent
feature of human cognition.
Properties of consciousness:
Consciousness restricts our attention. In this way it
controls what we notice and think about. Thus,
consciousness keeps our brains from being
overwhelmed by stimulation.
Consciousness combines sensation with learning and
memory. Thus consciousness is an interpretation of
the world.
Consciousness helps us select personally meaningful stimuli
from the input of our senses. In this way, consciousness
helps us make a mental record of the most meaningful
elements in our lives.
Consciousness allows us to draw on lesions stored in
memory. Thus, we are not like simpler organisms, prisoners
of the moment. Rather, we can bring both the past and the
future into consciousness, as we evaluate alternative
responses and imagine the effectiveness of their
consequences.
Levels of Consciousness
Nonconscious Process – involves information processed in
the brain but not represented in consciousness or memory.
Preconscious – memories that lie in the background of your
mind until they are needed such as the memory of your
first kiss.
Subconscious Processing – storing of background or non
essential information in the consciousness without
intentionally trying to.
Unconscious – houses memories, desires, emotions, and
feelings that would be threatening if brought to
consciousness.
Since the early 20th century, human sleep has been
described as a succession of five recurring stages: four
non-REM stages and the REM stage. A sixth stage, waking,
is often included. Waking, in this context, is actually the
phase during which a person falls asleep. Rapid eye
movement (REM) sleep is marked by extensive physiological
changes, such as accelerated respiration, increased brain
activity, eye movement, and muscle relaxation. People dream
during REM sleep, perhaps as a result of excited brain
activity and the paralysis of major voluntary muscles.
Sleep quality changes with
transition from one sleep stage
into another. Although the
signals for transition between
the five (or six) stages of sleep
are mysterious, it is important to
remember that these stages are,
in fact, discretely independent
of one another, each marked by
subtle changes in bodily function
and each part of a predictable
cycle whose intervals are
observable.
Waking
The waking stage is referred to as relaxed
wakefulness, because this is the stage in which
the body prepares for sleep. All people fall
asleep with tense muscles, their eyes moving
erratically. Then, normally, as a person becomes
sleepier, the body begins to slow down. Muscles
begin to relax, and eye movement slows to a
roll.
The Sleep Cycle
A normal night's sleep consists of alternating "NREM" and
"REM" sleep. "REM" stands for "Rapid Eye Movement" and is
the phase of sleep where the brain is the most active and
most dreams occur. "NREM" is Non-REM.
NREM sleep is itself divided into four different stages. The
combination of these five stages (four NREM, one REM)
creates a cycle that lasts around ninety minutes on average
and repeats several times during the night.
At the end of each cycle many people actually wake up
briefly. Most people don't even remember this; however
some poor sleepers may wake fully.
NREM Sleep
The first stage of NREM sleep is "drifting off". It lasts ten
minutes or so and is accompanied by hypnagogic imagery often
confused with lucid dreams. The sleeper is still half-awake and
might believe themselves to be "just resting the eyes".
NREM stage 2 represents the lightest stage of "real" sleep.
The sleeper can be wakened but with more difficulty than in
stage 1. Brain waves become larger and the body gradually
shuts down. During NREM stage 2 sleep becomes slowly deeper
until...
NREM stage 3 is the threshold to deep sleep. It usually occurs
between thirty to forty-five minutes after starting to sleep.
In NREM stage 3 the sleeper is much more difficult to waken
and the large, slower delta brainwaves are generated.
NREM stage 4 is "deep sleep". It is during deep sleep that the
body gets its most rest and does its best repair work. A
sleeper in deep sleep will be very difficult to awake - sleep
walking (somnambulism) sometimes occurs during this stage.
The first deep sleep period of the night is the longest and the
deepest. After the deep sleep period is over the sleeper
reverses the pattern, moving back up to NREM stage 2 then
entering REM sleep.
Lucid Dreams
We all know how real dreams can seem. Lucid dreams are
even more real - and have the advantage that you are in
control. They are the ultimate "virtual reality".
A lucid dream is as vivid and real as the "real" waking life.
Yet you know you're dreaming; you can control the dream.
In a lucid dream you can go anywhere, meet anyone, do
anything. Anything you can imagine, you can experience as
real.
Life's too short; we need to live every minute
to the full. Lucid dreaming is a technique that
allows us to make use of some of those hours
otherwise wasted in sleep. In our lucid dreams
we can analyze our dream symbols, face our
challenges and have fun!
It's important to recognize that lucid dreaming - "lucidity" occurs in the middle of true sleep. The imagery you experience
on the edges of sleep -the hypnagogic & hypnopompic states is not lucid dreaming. Those states, fun as they are, are more
akin to daydreaming. Imagine that but a hundred times
sharper, more detailed and more real - that's the lucid dream
experience.
In a lucid dream you
are totally conscious
yet still asleep. You'll
know it when you
experience it.
Dreams and culture
Ancient Israelites interpreted drams as messages from God.
In China dreaming held an element of risk. During a dream,
the ancient Chinese believed. The soul wandered about
outside the body. For that reason they
were reluctant to awaken a
sleeper hastily, lest the soul not
find its way back to the body.
Many African and Native
American cultures, dreams were
an extension of waking reality.
Consequently, when traditional
Cherokee Indians dreamed of
snakebite, they received
appropriate emergency treatment
upon awakening.
At the beginning of the 20th century, Sigmund Freud
laid out the most complex and comprehensive theory of
dreams and their meanings ever developed—a theory
that has since enjoyed enormous influence, despite a
lack of evidence to support it. In psychoanalytic theory,
dreams have two main functions: to guard sleep (by
disguising disruptive thoughts with symbols) and to
serve as sources of wish fulfillment.
Freud also taught that
interpreting dreams can help
people understand themselves
better, and so dream analysis has
become a central feature of
psychoanalytic therapy.
An altered state of consciousness occurs when some aspect
of normal consciousness is modified by mental, behavioral, or
chemical means.
The term “hypnosis” derives from Hypnos, the name of the
Greek god of sleep. Authorities would say hypnosis involves
a state of awareness characterized by deep relaxation,
heightened suggestibility, and highly focused attention.
Dramatic stage performances of hypnosis give the
impression that the power of hypnosis lies with the
hypnotized.
To view meditation as an altered state of consciousness may
reflect a particular Western worldview, for Asian beliefs
about the mind are typically different from those of
Western cultures.