What are the different states of consciousness?

John Locke defined consciousness as "the perception of what passes in a man’s own mind." Today’s scientist refers to consciousness as a person’s awareness of the sensations, thoughts and feelings being experienced at a given moment. It can vary in terms of how aware one is of outside stimuli; from an active to a passive state; and in terms of whether it is artificially induced or occurs naturally. An alternate state of consciousness is said to exist when mental functioning seems changed or out of the ordinary to the person experiencing the state. The functions of consciousness are (a) monitoring our environment and ourselves so that we are aware of what is happening within our bodies and in our surroundings: and (b) controlling our actions so that they coordinate with the events in the outside world. Not all events that influence consciousness are at the center of our awareness at a given moment. Memories of personal events and of the knowledge accumulated during a lifetime that are accessible but are not currently part of one’s consciousness are called preconscious memories. Events that affect behavior even though we are not aware of perceiving them influence us subconsciously.

What are them major characteristics of sleep and dreams?

Sleep, a period of rest for the body and the mind, has five stages that are distinguished by distinct patterns of brain waves and other psychological responses. Stage 1 is mark by the appearance of theta waves. Stage 2 is distinguished by the onset of sleep spindles. Sleep spindles diminish in stage 3 and are replaced in stage 4 by delta waves. Heart rate, respiration, and muscle tension steadily decline during the first four stages. After completing stage 4, people go back through stages 3 and 2 before entering the REM stage. Most adults sleep between 6 and 9 hours, 25 percent of which is spent in REM sleep. Rapid Eye Movement sleep is characterized by an increase in heart rate, a rise in blood pressure, an increase in the rate of breathing. Most striking is the rapid movement of the eyes, which dart back and forth under closed eyelids. Dreams occur during this stage. Dreaming occurs during REM sleep. REM sleep seems to be critical to human functioning, whereas other stages of sleep are less essential.

Dreams are a series of images, thoughts and emotions occurring during sleep. According to Freud, dreams have both manifest content (their apparent story line) and a latent content (their true meaning). He suggested that the latent content provides a guide to a dreamer’s unconscious, revealing unfulfilled wishes or desires. Many psychologists disagree with this view; they suggest that the manifest content represents the true import of the dream. The reverse learning theory suggests that dreams represent a process in which unnecessary information is "unlearned" and removed from memory. In this view, dreams have no meaning. In contrast, the dreams as survival theory suggests that information relevant to daily survival is reconsidered and reprocessed. Finally, the activation synthesis theory proposes that dreams are a result of random electrical energy. This electrical energy randomly stimulates different memories, which are then woven into a coherent story line.

Daydreams are "thoughts that divert attention away from an immediately demanding task." They are not characterized by unique physiological patterns. The type of daydream you have may affect your behavior, particularly in relation to alcohol or drug abuse. Daydreaming may occur 10 percent of the time is a typical part of consciousness.

What are the major classifications of drugs, and what are their effects?

Drugs can produce an altered state of consciousness. However, they vary in how dangerous they are and in whether or not they are addictive, producing a physical or psychological dependence. People take drugs for several reasons: to perceive the pleasure of the experience itself, to escape from everyday pressures, to attain religious or spiritual states, to follow the model of prestigious users or peers, or to experience the thrill of trying something new and perhaps illegal. Whatever the cause, drug addiction is one of the most difficult behaviors to study.

Four common depressants are alcohol, sedatives, tranquilizers and nicotine. They all inhibit neural activity. Alcohol reduces social inhibitions. Drinking rate, stomach content, and gender affect the amount of alcohol that reaches the brain. Sedatives are used to induce sleep and in lower doses, they induce a relaxed feeling of well being, poor concentration , and impaired motor coordination. Tranquilizers such as Librium and Valium help relieve anxiety. Nicotine is often classified as a stimulant because it initially stimulates the nervous system, but we classify it as a depressant because it ultimately suppresses the central nervous system.

Narcotics (also known as opiates) induce sleep and relieve pain. The pain relieving effects of opiates is achieved by boosting the effects of endorphins.

Stimulants include caffeine, amphetamines and cocaine. The benefits of caffeine are increases in both mental and physical work capacity. The costs are that higher and higher doses are required to achieve this lift. One who stops taking caffeine experiences withdrawal symptoms. Amphetamines stimulates the central nervous system by enhancing the effects of excitatory neurotransmitters. They enhance the feelings of alertness and speed up reaction times, but they also increase errors in decision making. Cocaine blocks the removal of norepinephrine and dopamine; it arouses self confidence and optimism, but also can lead to agitation, sleeplessness, paranoia, sudden depression, and permanent brain damage.

Hallucinogenic drugs include marijuana, mescaline, psilocybin, LSD and PCP. Drug-induced hallucinations seem to have for stages, and to share common patterns across cultures.

Is hypnosis an alternate state of consciousness?

Hypnosis produces a state of heightened susceptibility to the suggestions of the hypnotist. Physiological measures do not distinguish hypnosis from waking consciousness, which leaves room for debate about whether hypnosis induces an alternate state of consciousness. However, significant behavioral changes occur during hypnosis which includes increased concentration and suggestibility, heightened ability to recall and construct images, lack of initiative and acceptance of suggestions that clearly contradict reality. However, people cannot be hypnotized unwillingly.

Meditation is a process combining mental and physical acts to achieve an altered state of consciousness. This process can reduce oxygen consumption, respiratory rate, heart rate, blood pressure, and muscle tension. It also induces subjective responses characterized by feelings of calm and well-being. Meditation is associated with reduced drug consumption.