4/21/2016

1

4/21/2016

2

consists of evaluating and filtering information from the environment while being aware of doing so

Attention is the link between the information that our senses receive and the information that we actually perceive. It prevents us from becoming overwhelmed by incoming information because it keeps some information from ever reaching consciousness. Many parts of the brain are active during attention, but the frontal lobe is responsible for attention to verbal stimuli and the parietal lobe for visual and spatial information. (Posner, 1995, 2001)

4/21/2016

3

Humans have the capacity for selective attention in which certain stimuli are screened from consciousness at will We all have the ability to follow one conversation during a dinner party, despite the distractions of other conversations. Called the cocktail party phenomenon, this was studied by E. Colin Cherry using a dichotic listening device

In a dichotic learning task, the subject wears headphones that deliver different messages to each ear. The subject is asked to attend to only one of the messages. This process is called shadowing

4/21/2016

4

Researchers have found that although the subjects are not typically conscious of the message in the unattended ear, they are unconsciously aware of it. For example, they tend to be aware of changes in the quality of the message such as the speaker’s voice in the unattended ear.

The act of paying deliberate attention is called mindfulness, and the lack of attention is called mindlessness Ellen Langer gave the example of the tragic fate of a 1982 flight. Pilot’s mindlessness noted that the de-icer was turned off, despite that they were about to take off in the middle of a snowstorm. 74 people killed. Most states of mindlessness do not have such severe consequences: Milk put away in cupboard, Boston shake.

4/21/2016

5

Broadbent proposed an early filter theory that we filter our information immediately after it passes through the sensory register and before it receives any top-down processing. This theory is not supported by dichotic listening task findings that indicate subjects recognize their own name in the unattended ear.

4/21/2016

6

Another filter theory proposes that the filter doesn’t block information, but weakens it. Information that is not important to us is not consciously perceived. Information with some relevance or importance to us will not be weakened much and consequently will be consciously perceived.

More modern theories of selective attention have rejected the idea of attentional filters in favor of speaking in terms of attentionalresources. They propose that each of us has a single pool of attentional resources to use at any given time. If the situation requires it, we can divide our attentional resources between various tasks, but there is only so much to go around. The more similar tasks are, the more they will compete for the same resources.

4/21/2016

7

Consciousness allows us to monitor our internal and external environments and control our behaviors through planning and decision making. These processes of monitoring and controlling occur at multiple levels of consciousness.

Conscious Level Preconscious Level Subconscious Level

Items that are not currently in consciousness, but that can be brought there easily, define the preconscious level of consciousness. Many items are at the preconscious level such as automatic behaviors, or, those behaviors that can be accomplished without conscious control.

4/21/2016

8

The most common experience of the preconscious level Occurs whenever you know that you know an item, but cannot retrieve it. Information that is not fully accessible, but is available for conscious thinking.

This occurs when a word stimulus is presented so rapidly, that observers are generally not aware of having seen it. However the word can still alter behavior and emotions. Despite evidence of the existence of subliminal perception, the subliminal persuasion attempted on self-help subliminal tapes does not seem to occur in practice. Subliminal advertising

4/21/2016

9

Items stored at the subconscious level are not easily brought into consciousness. Freud interpreted those items as being threatening and repressed or actively kept in the subconscious Freud’s position was that although subconscious information was unavailable to us at the conscious level, it still exerted an important and powerful control over our behavior.

Altered states of consciousness are those different from normal, waking consciousness. Usually individuals in such states are more accepting, have different self-perceptions, have less critical cognitive processes, and are less inhibited. Sleep is one of the most common altered states of consciousness experienced, but others including hypnosis, medication, and chemically-induced states have altered consciousness.

4/21/2016

10

The ascending reticular activating system is the most important part of the brain when it comes to the regulation of the sleep-wake cycle. However, other parts of the brain and several brain chemicals also play a role in sleep. Some of these chemicals are GABA, norepinephrine, and dopamine.

4/21/2016

11

Although scientists disagree, two main theories have been proposed to explain sleep. One is evolutionary and claims that sleep is functional in preventing activity during the night. The other is chemical and claims that sleep serves a restorative function. However, scientists do agree that sleep is the best predictor of prolonged longevity.

One view is that sleep evolved as a protective mechanism. For many species, the night is a time of danger. During the dark hours, the rise of injury and predation is at its highest for many species. Therefore, if a particular species does not require 24 hours for feeding, it is safer for them to sleep at night.

4/21/2016

12

Support for this evolutionary theory comes from the fact that the amount of time a species needs for foraging/hunting and the species ability to hide themselves at night seem to be related to the amount of time a species tends to sleep at night. Alternately animals sleep at times that serve to offer the best protection. For example, animals, whose predators rely on vision to hunt, sleep, well hidden, during the daylight hours.

Another theory on the function of sleep maintains that sleep works to restore the body and remove wastes. Researchers have been searching for support for this chemical theory of sleep by attempting to isolate those chemicals that cause the onset of sleep in the body.

4/21/2016

13

Some evidence suggests that a buildup of five amino acids including muramic acid in the cerebrospinal fluid may be responsible for causing sleep. Other such substances, delta-sleep-inducing peptide (DSIP) and sleep-promoting substance (SPS), also have been isolated.

Sleep is an example of a circadian rhythm, or a 24 hour biological cycle. Infants sleep about 17 hours a day in fits and spurts. By five to seven years, most people have adopted an adult sleep wake cycle of eight hours of sleep a night and 16 hours of wakefulness during the day.

4/21/2016

14

There is considerable variation in the amount of sleep a person requires a day. Some sleep less than 4.4 hours, and other sleep more than 9.5 hours on average. Not only do people vary with respect to how much they sleep, people also differ with respect to when they like to sleep. Cultural and individual factors, such as the time of the evening meal, can affect the typical time at which a person goes to sleep.

Despite the individual difference for sleep-wake cycles, they all roughly correspond to the cycle of light on the planet. If people are placed in an environment in which there is no exposure to outside sunlight and no clocks, their sleep-wake cycle alters to the point where their subjective days are 24 hours and eighteen minutes long. They also spend slightly more time awake than they did when exposed to the light-dark cycle of the sun.

4/21/2016

15

Jet lag is a common manifestation of disturbance in the sleep-wake cycle that occurs when our exposure to the outside light-dark cycle is altered because of a change in time zones. Generally speaking, jet lag is more intense when people fly to the east and lose daylight hours.

It is believed that the pineal gland may play a role in regulating the sleep wake cycle via the manufacture of chemical agents like the hormone melatonin. Another possible agent is the amino acid tryptophan which is a precursor to serotonin. In addition, light levels have been shown to alter sleep cycles, and aid in getting over jet lag. Although researchers have indeed found chemicals that can cause the onset of sleep, the theory that sleep is chemically produced has not been proven.

4/21/2016

16

Asking subjects to stay awake as long as possible is a popular way of investigating sleep. Typically, subjects pass through similar stages. After the first sleepless night little is different. After the second such night, they tire during the afternoon and may fall asleep, but they will usually deny it.

After the third night, they are quite tense and irritable, may fall into numerous micro-sleeps (with sleep-like electroencephalographic patterns), and may experience delusions and hallucinations (especially auditory). After the fourth night, subjects exhibit more bizarre behaviors, such as paranoia. Due to ethical reasons, experimental subjects have not been deprived of sleep for longer periods.

4/21/2016

17

Analyses of sleep using electroencephalograms (EEGs) have shown that nearly all individuals sleep in five stages. EEGs show a transition from the relaxed waking state, or alpha-waves to the first stage of sleep.

Stage one sleep is characterized by smaller, faster, and more irregular waves. If awakened during this stage, the subjects may have trouble making sense of their thoughts and may not believe they were asleep.

4/21/2016

18

Stage 2 sleep where subjects spend over half of their sleep time, shows large EEG waves, sleep spindles, and large slow waves called K-complexes.

The third and fourth stages of sleep are characterized by delta waves. In stage three the EEG exhibits 20-50% delta waves, and in stage 4 more than 50% delta waves. Both these stages are called deep sleep.

4/21/2016

19

The final stage of sleep is called REM sleep, for rapid eye movement sleep. The other four stages are often collectively referred to as N-REM sleep, for non-REM sleep. Subjects awakened during REM sleep are much more likely to report dreaming then subjects awakened in the N-REM stages of sleep.

Also, EEG records during REM sleep closely resemble those of alert and awake subjects, yet during REM sleep, subjects are very difficult to awaken. Because of this unusual pattern, REM sleep is sometimes called "paradoxical sleep."

4/21/2016

20

Insomnia Narcolepsy Sleep Apnea Sleepwalking

4/21/2016

21

Insomnia is characterized by having difficulty falling asleep, waking up often during the night, or waking up very early and then being unable to fall back to sleep. Many people experience transient bouts of insomnia due to stress in their lives, poor sleep habits, or lifestyle factors such as caffeine consumption or exercise habits.

Roughly 6% of adults report having medical treatment for sleep problems, another 15% report serious insomnia, while roughly another 15% report occasional or mild bouts of insomnia. Like many other sleep disorders, insomnia is most common among women and the elderly.

4/21/2016

22

Sedatives can be used to treat insomnia, but they do not represent a long-term cure for the disorder. Sedatives actually work to lessen REM sleep, which can exacerbate insomnia in the end. Additionally, sedatives often impair daytime functioning and they are potentially addictive.

Some (about 5% of people going to sleep clinics) believe they are having sleep problems when they are not. These cases are called pseudo-insomnia, or sleep state misperception.

4/21/2016

23

Narcolepsy is a disorder of the waking state that seems to run in families. Narcolepsy is characterized by uncontrollable and sudden bouts of sleep. The narcoleptic may suddenly fall into a deep sleep while performing normal waking-state activities such as driving or walking. Typically, these bouts of sleep will last for 10 to 15 minutes.

The cause of narcolepsy is not known, but one theory proposes that for the narcoleptic, REM sleep may not be fully differentiated from the waking state. This disorder affects one or two people in every thousand.

4/21/2016

24

Sleep apnea also is thought to run in families, and its cause is not fully understood. The person suffering from sleep apnea will experience periods during sleep in which he or she stops breathing for a few seconds. These episodes may be experienced hundreds of times during the night’s sleep and they are potentially hazardous because they deprive the body of oxygen.

Apnea is commonly associated with obesity and alcoholism in adults, and it has been linked to sudden infant death syndrome (SIDS) in infants is found frequently in premature infants, but they typically outgrow the disorder. Treatment of sleep apnea and adults is difficult, but weight loss sometimes helps.

4/21/2016

25

Sleepwalking, or somnambulism, is a disorder in which sufferers walk around and sometimes talk in their sleep. Sleepwalking occurs in stages three or four of Non-REM sleep when the sufferer is unlikely to be dreaming. During a bout of sleepwalking, the subject may move about with eyes open and a rigid facial expression, but his or her perceptions are likely to be severely altered.

Because of the alterations in perception, sleepwalkers do pose a danger to themselves. They may walk into objects, fall down stairs, and so on. It is not, however, dangerous to awaken a sleepwalker. The cause of sleepwalking is unknown but children are more likely than adults to suffer from this disorder.

4/21/2016

26

All people dream every night, whether they remember their dreams or not. Freud's view of dreams is probably most well-known. He thought dreams were the "royal road to the unconscious." However, his conception of dream content as largely symbolic has less support now.

Others have proposed a dreams reflect everyday concerns disguised in a language that is peculiar to the dream state or that dreams have no particular meaning at all. Other theories take a problem-solving view of dreams. In this view, we dream in order to work out problems we are experiencing during wakefulness.

4/21/2016

27

McCarley and Hobson's activation-synthesis hypothesis of dreaming proposes that neurological activation during sleep results in different cognitive interpretations (synthesis) than those same changes do while awake, explaining feelings of being chased or of floating or flying. No adequate explanation of the purpose of dreams has been made yet, and because of the highly personal nature of dreams, none may ever be made.

Despite the entertaining nature of many dreams, some dreams can be very frightening. A nightmare is a dream that produces intense feelings of anxiety. These dreams can be so frightening that they cause the person to awaken and remember in detail the events of the dream. Nightmares are more common in children and during times of stress, but they do not require treatment unless they are extreme in nature.

4/21/2016

28

Night terrors occur when a person awakens from N-REM sleep with feelings of terror but cannot remember having had a nightmare. Night terrors are more common in children than adults, especially among children aged 3-8 years.

Daydreaming as an intermediate state between waking and sleeping. During daydreaming the external world is relatively ignored compared to the internal. Daydreaming can be a problem, but often it results in generating more creative thoughts than usual.

4/21/2016

29

Hypnosis is an altered state of consciousness usually marked by extreme relaxation and sensitivity to suggestion. Posthypnotic suggestion also may be given to hypnotized people. Typically, hypnotized people have little or no recall of being hypnotized, but they may be induced to feel things they would not ordinarily feel, or to remember things they could not while not hypnotized.

4/21/2016

30

Hypnosis was discovered by Franz Anton Mesmer in the 18th century. Mesmer called it animal magnetism because he believed the effects were due to his ability to redistribute the subject’s body fluids. Later, a commission decided that the effects were due to experimenter effects-and-demand characteristics, or, they were similar to a placebo effect.

For a while hypnotism was known as mesmerism and was used more for the entertainment of others than for serious reasons. In the 20th century, scientists were able to show, using the simulation paradigm, that some of the effects of hypnotism are not reproducible by non-hypnotized subjects. These findings indicate that hypnosis is indeed an altered state of consciousness.

4/21/2016

31

Credible theories of hypnosis include: Deep relaxation theory Hypnosis as an epiphenomenon, and Neo-dissociative theories.

The deep relaxation theory of hypnosis, first proposed by Ivan Pavlov, posits that hypnosis is a special type of sleep state. Although we know that true sleep-state EEG patterns differ from those seen during hypnosis, there may still be a connection between the two states.

4/21/2016

32

Another theory is that hypnosis is an epiphenomenon that occurs as subjects try to meet what they perceive to be the expectations of the hypnotist. In trying to "please" the hypnotist, they get caught up in their role as a hypnotized person and behave in unusual manners.

The neo-dissociative theory is the most widely accepted today. Neo-dissociative theory proposes that hypnosis is a state in which people dissociate or split part of their consciousness from their normal conscious level of processing. When dissociative, part of the person attends to the demands of the hypnotist while another part of the person’s mind acts as the hidden observer of the persons actions. For example, a hypnotized subject may respond to a hypnotist suggestion that he or she cannot feel a painful stimulus but at the same time also may be able to describe the pain he or she claims not to feel.

4/21/2016

33

People’s susceptibility to hypnosis varies widely, and therapies using hypnosis are most successful with patients who are easily hypnotized. The therapeutic use of hypnosis to retrieve repressed or hidden memories remains controversial.

The current research on hypnosis and its ability to uncover hidden memories indicates that memories retrieved through hypnosis need to be treated with a good deal of skepticism. Often subjects’ recall of memories under hypnosis seems to be painted by suggestions made either intentionally or inadvertently by the hypnotist.

4/21/2016

34

Meditation is the shifting of attention from the external world to the internal world. There is an emphasis on quiescence and receptivity. In concentrative meditation, meditators actively focus on particular objects while attempting to ignore all other distracting objects. Zen is a Buddhist method of concentrated meditation that uses repetition, body positions, and koans (paradoxical questions).

Yoga is another form that uses exercise as part of a larger scheme. Yoga can be used to control involuntary aspects of the autonomic nervous system. Practitioners also used mantras, or words that help them focus their awareness. In opening-up meditation, unlike the kinds above, practitioners seek meditation while they are in the midst of their everyday activities. This is done in an attempt to expand one's awareness of everyday events, rather than to remove one's consciousness from the mundane existence of everyday life

4/21/2016

35

Relaxation, measured by various variables, seems to be the main positive effect of meditation. There have been reports that meditation has helped many psychiatric and physical disorders. Meditation also seems to increase production of alpha waves. Many practitioners of meditation also report that meditation helps move them towards an enlightened state of consciousness, an effect that many drug users hope to achieve.

Although drugs can be used to fight disease, reduce pain, or alter consciousness, in this chapter the discussion is limited to psychoactive drugs, or drugs that produce psychopharmacological effects on the body. The psychoactive drugs can be divided into four categories: narcotics, central nervous system depressants, central nervous system stimulants, and hallucinogens.

4/21/2016

36

Narcotics, from the Greek word for "numbness," are potent analgesics or painkillers. Originally the term narcotic applied only to opiates, but now it also applies to the synthetic opiates called opioids. Illegal use of narcotics typically involves intravenous injection, smoking, or inhalation. Medical use usually involves oral ingestion or intravenous injection of narcotics. Narcotics lead to pain reduction, numbness, and a sense of well-being.

Because of their highly addictive nature, narcotics are prescribed only for severe pain, and, in lower doses, relief of diarrhea. Narcotics cause pain relief, relaxation, and sleepiness, and they also cause constipation.

4/21/2016

37

Codeine, which exploits the cough suppressant effects of narcotics, is used for cough relief. Users are impaired enough the driving is hazardous. Side effects include pupillarycontraction, sweating, nausea, and respiratory depression, which makes doing cognitive tasks very difficult while under the influence.

Essential overdose is a problem for narcotic users, as is tolerance. As the user continues to use a narcotic, he or she develops a tolerance to the drugs such that more of the drug will be required to produce the same effect that a smaller dose once produced. As a tolerance builds in the user, dependency occurs. Eventually, the euphoric effects of narcotics decline, so the main reason users continue narcotic use to avoid withdrawal symptoms.

4/21/2016

38

Narcotics resemble neurotransmitters biochemically. They are similar to endogenous morphines or endorphins, the body's natural painkillers. When users attempt to discontinue narcotics, lowered levels of endorphins occur, as do withdrawal symptoms including chills, sweating, stomach cramps, diarrhea, headache, and chronic nausea.

Acute toxicity, or overdose, is usually treated with naloxone, a drug that occupies opiate receptors more strongly than the opiate does, but only for a short time. The short-term effect of naloxone makes it unsuitable for use in cases of chronic toxicity.

4/21/2016

39

The two main methods of treating chronic toxicity, or addiction, is via maintenance and detoxification. Maintenance programs provide either the drug, or a substitute like methadone, under controlled conditions. Detoxification programs attempt to rid the person of the addictive effects and withdrawal symptoms of narcotic. Methadone also can be used in detoxification programs. Methadone binds to opiate receptor sites and reduces heroin cravings. The methadone dosages are then tapered off over a period of time until the patient is drug-free.

Central nervous system (CNS) depressants include alcohol and the sedative-hypnotics, drugs that lower CNS function. Alcohol is available to adult users throughout most of the United States as a recreational drug, while sedative-hypnotics are prescribed for insomnia and anxiety relief.

4/21/2016

40

Both can cause users to become intoxicated, or stupefied by the toxins in the depressants, and subject to mood swings. High doses of either lead to increased anxiety and irritability, slower reflexes, unsteady gait, slurred speech, impaired judgment, and death, directly or indirectly.

Historically produced from the natural fermentation of fruits and grains, alcohol use is so prevalent that many do not consider it a psychoactive drug. Users show wide variability in their susceptibility to its effects depending on usage patterns, body weight, and tolerance. Alcohol's effects begin to be manifested at blood levels between 0.03 and 0.05%. At these levels users typically are relaxed, uninhibited, and feel good.

4/21/2016

41

When the blood level reaches 0.10% most states consider users to be legally impaired can restrict motor vehicle use. At this level many users a show personality changes and slurred speech. A blood level of 0.20%, users are seriously impaired, and at blood levels above 0.40% users may die, usually from respiratory failure. Psychopharmacologically, alcohol first causes elation, then the general decrease in functioning.

Dopamine’s effectivenesss as a neurotransmitter is affected by alcohol, leading to reduced motor abilities and attention. Alcohol seems to raise people's level of arousal due to its inhibitory effect on the inhibitory neurotransmitters in the brain (i.e., inhibition of inhibition creates excitation). At larger dosages, however, alcohol begins to inhibit the action of excitatory synapses and overall central nervous system depression results, especially in the sensorimotor areas of the brain.

4/21/2016

42

Alcoholism is a disease in which users cannot abstain from alcohol. Of the two thirds of adults who report they use alcohol, 5% are alcoholics. More seriously, the majority of violent crimes committed in the United States occur under the influence of alcohol.

Alcohol also contributes to a host of health problems at the societal level. On average alcoholism reduces one's lifespan by 10 to 12 years. Pregnant women especially should abstain from alcohol use because of the risks of fetal alcohol syndrome.

4/21/2016

43

Acute intoxication leads to hangover, which is cured only by the passage of time, although drinking nonalcoholic fluids and moderately exercising may speed the process. Withdrawal from chronic intoxication, however has more severe symptoms such as convulsions, hallucinations, and tremors. Treatment may include medical intervention and self-help groups like Alcoholics Anonymous.

Sedative-hypnotics are a second type of central nervous system depressant that are used to treat anxiety and insomnia. Barbiturates are the most widely used type of sedative-hypnotics. In low doses, barbiturates calm users through the inhibition of arousal, but in higher doses, they cause sleep, and, if the dosage is high enough, death by respiratory failure.

4/21/2016

44

Sedative-hypnotics are addictive, and users develop tolerance. The development of tranquilizers (benzodiazepines) has led to a decrease in the prescription of barbiturates for the treatment of anxiety. The benzodiazepines are a safer category of anti-anxiety drugs. They are effective at low dosages, do not cause drowsiness, and have less effect on the respiratory system. The benzodiazepines are the second most frequently prescribed drugs in the United States.

Both psychological and physiological dependence require treatment. Again, severe withdrawal effects exist (e.g., seizures and anorexia). And, unlike the narcotics, withdrawal from depressants can be life-threatening. Chronic toxicity to barbiturates is usually treated by maintenance and the substitution of phenobarbital. Counseling and support groups also may help those addicted to depressants.

4/21/2016

45

CNS stimulants also have a long history of use. They include caffeine, amphetamines, cocaine, and nicotine. Stimulants produce arousal or excitation in the brain either by directly stimulating the heart or by inhibiting the action of neurotransmitters that normally produce inhibition.

At low doses stimulants increase stamina and alertness, reduce hunger, and cause euphoria. Higher doses cause irritability and anxiety. Illegal use of stimulants, especially cocaine, has displaced narcotics use as the biggest drug problem in the United States.

4/21/2016

46

Of all the stimulants, caffeine is the most widely used. Some "national drinks" such as coffee, tea, maté,: drinks, and food such as chocolate are the most common sources of caffeine. Coffee contains the most caffeine with 11 to 29 mg per ounce.

Caffeine is addictive, and it works via the suppression of the effects of adenosine, a naturally occurring inhibitor in the brain. While moderate use appears not to be a health risk, the indications of the addiction are similar to those of more destructive drugs. Heavy use of caffeine may cause increased blood pressure and other autonomic effects. Withdrawal effects include headache, lethargy, irritability, constipation, and problems working.

4/21/2016

47

Amphetamines are synthetic drugs with powerful CNS stimulant effects. Users usually injest or inject amphetamines. The short-term effects of amphetamines are increased endurance, temperature, and heart rate. Amphetamines cause increased alertness and euphoria via the release of dopamine and norepinephrine at the synapse. Amphetamines also may prevent reuptake of these neurotransmitters and thereby increase their actions even more.

Serotonin synapses also may be affected by very high doses. When amphetamines use is long-term, serotonin levels may begin to drop in the brain. This may produce a state of malfunction within the central nervous system. Amphetamines are addictive, and tolerance and withdrawal do occur. Withdrawal symptoms include depression and fatigue.

4/21/2016

48

Overdose may cause intoxication, paranoia, confusion, hallucinations, and death (by respiratory failure or loss of an endogenous temperature control). Users who take amphetamines irregularly may suffer sensitization, a condition where in low doses of the drug have stronger than normal effects.

Cocaine or “coke", the strongest natural stimulant, has a history of use in the Americas by its native peoples. Refined from the coca plant, cocaine can be sniffed or smoked in "crack" form. Cocaine produces increased body temperature, constriction of peripheral blood vessels, feelings of increased mental ability, and excitement.

4/21/2016

49

High dosages of cocaine can cause hallucinations and seizures. The effects of cocaine stem, in part, from increased epinephrine and dopamine effects due to both increased secretion and the prevention of reuptake. Also contributing to its effect is the fact that cocaine prevents the reuptake of serotonin in the brain.

Increased sexual interest occurs initially, but long-term use leads to decreased sexual arousal and performance. Treatment for abuse is hindered by recovering users cravings for cocaine. Also, abuse affects users’ natural stimulant mechanisms, leading to anxiety, depression, lethargy, and feelings of loss of control. Preventative education about the effects of cocaine and support groups are probably the best ways to treat cocaine addiction at present.

4/21/2016

50

Tobacco is hazardous both to users and to those near smokers. Nicotine, the stimulant ingredient in tobacco, is one of the most addictive substances known. Nine out of 10 people who try smoking become addicted! Smoking by pregnant women has been linked to low birth weights and premature births.

Nicotine has both stimulant and deppressiveeffects, increasing respiration, heart rate, and blood pressure, but decreasing appetite. Nicotine increases the neurotransmission of a acetylcholine. Intoxication is chiefly seen in novice users because tolerance and dependence develop quickly. The effects of intoxication, when it is seen, include euphoria, lightheadedness, giddiness, dizziness, and tingling in the extremities.

4/21/2016

51

Prolonged use of tobacco has been linked to an increased risk of heart disease, specific cancers, gastrointestinal disease, and other health problems. Also, secondary smoke (or environmental tobacco smoke, EPS) has lately been recognized as a hazard to non-smokers, and has prompted many laws to be passed which restrict the use of tobacco products in many public places. Tobacco causes many deaths, as do the other stimulants taken in excess.

Acute toxicity from stimulants must be treated medically and is life-threatening. Most treatment of chronic stimulant abuse consists of individual or group psychotherapy. Many support groups (e.g., Narcotics Anonymous and Cocaine Anonymous) exist for persons addicted to stimulants, and they often help addicts change their lifestyle.

4/21/2016

52

Nicotine patches and gum have been used to treat tobacco use, but substitution therapies are not used to treat abuse of the other stimulants. Aversion therapies that attempt a classically condition aversion to tobacco smoke also been employed to help those addicted to nicotine.

Hallucinogenic drugs (psychedelics or psychotomimetics) change the way users perceive their internal reality and the environment. Hallucinogens produce hallucinations which are perceptual events that occur without environmental reference.

4/21/2016

53

Hallucinogens are believed by some psychologists to produce effects that are related to psychoses, but others disagree saying that the hallucinations produced by hallucinogens differ from those produced by psychotic disorders. The hallucinogenic drugs are mescaline, LSD, PCP, and marijuana.

Individual responses to hallucinogenic drugs varies among users, partly because of situational factors. Most hallucinogens’, such as LSD, physiological action is the result of serotonin inhibition. Because serotonin prevents dreaming during the waking state, the inhibition of serotonin during wakefulness produces a state that can be likened to dreaming while awake.

4/21/2016

54

The physiological action of the other hallucinogens is still unclear, but may involve stimulation of norepinephrine transmission.

LSD (lysergic acid diethylamide) was discovered by a chemist to accidentally ingested some. LSD is a powerful hallucinogenic drug with widespread physical and psychological effects.

4/21/2016

55

Among the perceptual and effective symptoms are vivid hallucinations, a sense of time alteration, tremors, nausea, dizziness, feelings of having had profound cognitive experiences, and mood swings. "Bad trips" occur when users become enmeshed in the drug response, especially during hallucinations.

Marijuana, the most commonly used hallucinogen, it is derived from the dried leaves that cannabis plant. Hashish is a more potent form of the drug made from the resin of the cannabis plant’s flowers. Because marijuana is usually smoked (it is also ingested), its effects can occur rapidly. The practice of smoking marijuana also contributes to the development of cancers of the lung and lips of users.

4/21/2016

56

Normal doses of marijuana cause users to perceive alterations in time, feel disconnected, have food cravings, and talk more or less. Even moderate doses of marijuana can cause short-term learning and memory impairments. Hallucinations usually result only when high doses have been taken. Other than marijuana’s carcinogenic effects, scientists disagree over marijuana's long-term effects on users, but some argue that long-term use damages nerves and the reproductive system.

PCP (phencyclidine) is cheap and easily made, making it a popular drug among some young adolescents. PCP is believed to act on synapses that play a role in learning, and the potential for cognitive deficits are great. PCP also causes large-scale cognitive and perceptual distortions. Ecstasy or MDMA is another hallucinogen that has an effect similar to PCP's.

4/21/2016

57

Chronic use of hallucinogenic drugs can be quite serious and threatening to health. Chronic use has been linked to psychotic episodes, severe depression, a worsening of previous psychotic behavior, and flashbacks. Treatment of hallucinogen abuse often involves allowing the body to metabolize the drug while the patient is in protective custody of the therapist, who attempts to "talk the user down," as the drug is allowed to run its course.

Tranquilizers can be used, and, as a last resort, antipsychotic drugs. The problem of drug use is one of great interest of society and to science. The reasons why humans take drugs are still largely unknown, but the effects to users and the consequences to society are large, especially with tobacco, alcohol, and cocaine use.