| A | B |
|---|
| Consciousness | our awareness of ourselves and our environment |
| circadian rhythm | the biological clock; regular bodily rhythms that occur on a 24-hour cycle. |
| REM sleep | a recurring sleep stage during which vivid dreams commonly occur. Also known as paradoxical sleep, because the muscles are relaxed (except for minor twitches) but other body systems are active. |
| alpha waves | the relatively slow brain waves of a relaxed, awake state. |
| sleep | periodic, natural loss of consciousness—as distinct from unconsciousness resulting from a coma, general anesthesia, or hibernation. |
| Hallucinations | false sensory experiences, such as seeing something in the absence of an external visual stimulus. |
| delta waves | the large, slow brain waves associated with deep sleep. |
| NREM sleep | encompasses all sleep stages except for REM sleep. |
| insomnia | recurring problems in falling or staying asleep. |
| narcolepsy | a sleep disorder characterized by uncontrollable sleep attacks. The sufferer may lapse directly into REM sleep, often at inopportune times. |
| sleep apnea | a sleep disorder characterized by temporary cessations of breathing during sleep and repeated momentary awakenings. |
| night terrors | a sleep disorder characterized by high arousal and an appearance of being terrified; occur during Stage 4 sleep, within two or three hours of falling asleep, and are seldom remembered. |
| dream | a sequence of images, emotions, and thoughts passing through a sleeping person’s mind; are notable for their hallucinatory imagery, discontinuities, and incongruities, and for the person's delusional acceptance of the content and later difficulties remembering it. |
| manifest content | according to Freud, the remembered story line of a dream |
| latent content | according to Freud, the underlying meaning of a dream |
| REM rebound | the tendency for REM sleep to increase following REM sleep deprivation (created by repeated awakenings during REM sleep). |
| hypnosis | a social interaction in which one person suggests to another that certain perceptions, feelings, thoughts, or behaviors will spontaneously occur. |
| posthypnotic suggestion | a idea, made during a hypnosis session, to be carried out after the subject is no longer hypnotized; used by some clinicians to help control undesired symptoms and behaviors. |
| dissociation | a split in consciousness, which allows some thoughts and behaviors to occur simultaneously with others. |
| psychoactive drug | a chemical substance that alters perceptions and moods. |
| withdrawal | the discomfort and distress that follow discontinuing the use of an addictive drug. |
| addiction | compulsive drug craving and use, despite adverse consequences. |
| tolerance | the diminishing effect with regular use of the same dose of a drug, requiring the user to take larger and larger doses before experiencing the drug’s effect. |
| depressants | drugs (such as alcohol, barbiturates, and opiates) that reduce neural activity and slow body functions. |
| psychological dependence | the need to use a non-addictive drug, such as to relieve negative emotions |
| physical dependence | the body's biological need for a drug, marked by unpleasant withdrawal symptoms when the drug is discontinued. |
| stimulants | category of drugs (includes caffeine, nicotine, and the more powerful amphetamines, cocaine, and Ecstasy) that excite neural activity and speed up body functions. |
| amphetamines | synthetic man-made drug that stimulates neural activity, causing speeded-up body functions and associated energy and mood changes. |
| THC | the major active ingredient in marijuana; triggers a variety of effects, including mild hallucinations. |
| Ecstasy (MDMA) | a synthetic stimulant and mild hallucinogen. Produces euphoria and social intimacy by triggering release of stored serotonin, but with short-term health risks and longer-term harm to serotonin-producing neurons and to mood and cognition. |
| hallucinogens | category of psychedelic (“mind-manifesting”) drugs that distort perceptions and evoke sensory images in the absence of sensory input. |
| LSD | acid - a powerful hallucinogenic drug that is similar to serotonin |
| near-death experience | an altered state of consciousness reported to be similar to drug-induced hallucinations that often involves visions of bright lights or out of body experiences. |
