consciousness, psychoactive drugs, sleep and dreams terms

consciousness

our awareness of ourselves and our environment

blindsight

detection without conscious awareness

selective attention

the focusing of conscious awareness on a particular stimulus

inattentional blindness

failing to see visible objects when our attention is directed elsewhere

change blindness

failing to notice changes in the environment

circadian rhythms

the biological clock; regular bodily rhythms (for example, temperature & wakefulness) that occur on a 24- hour cycle

psychoactive drug

a chemical substance that alters perceptions and moods

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

addiction

compulsive drug craving and use, despite adverse consequences

withdrawal

the discomfort and distress that follow discontinuing the use of an addictive drug

physical dependence

a physiological need for a drug, marked by unpleasant withdrawal symptoms when the drug is discontinued

psychological dependence

a psychological need to use a drug, such as to relieve negative emotions

depressants

drugs (such as alcohol, barbiturates, and opiates) that reduce neural activity and slow body functions

stimulants

Drugs (such as caffeine, nicotine, and the more powerful amphetamines, cocaine, and Ecstasy) that excite neural activity and speed up body functions.

barbiturates

drugs that depress the activity of the central nervous system, reducing anxiety but impairing memory and judgment

opiates

opium and its derivatives, such as morphine and heroin; they depress neural activity, temporarily lessening pain and anxiety

hallucinogens

psychedelic ("mind-manifesting") drugs, such as LSD, that distort perceptions and evoke sensory images in the absence of sensory input

sleep cycle

a period of sleep lasting about 90 minutes and including one or more stages of NREM sleep, followed by REM sleep

NREM stage 1

just drifting to sleep, may experience fantastic images and/or auditory hallucinations, mix of alpha and theta waves

NREM stage 2

more relaxed, clearly asleep- sleep spindles occur

NREM stage 3

deepest sleep, hard to awaken... only occurs during the first few cycles of the night, characterized by large delta waves

REM cycle

rapid eye movement sleep; a recurring sleep stage during which vivid dreams commonly occur. Also known as paradoxical sleep, because the muscles are relaxed but other body systems are active

sleep spindles

short bursts of brain waves detected in stage 2 sleep

K-Complexes

a brief, high-amplitude spike-and-rebound waveform recorded in the scalp electroencephalograph during sleep onset

dreams

a sequence of images, emotions, and thoughts passing through a sleeping person's mind

wish fulfillment

Sigmund Freud suggested that dreams provide a safety valve to discharge unconscious wants and desires.

manifest content

the remembered story line of a dream

latent content

the underlying meaning of a dream

activation synthesis

Suggests that the brain engages in a lot of random neural activity. Dreams make sense of this activity (b/c the brain doesn't like randomness)

information processing

dreams help us sift, sort, and fix out the day's events and consolidate our memories

sleep disorders

involves problems with the quality, timing, and amount of sleep which result in daytime distress and impairment in functioning (insomnia, narcolepsy, sleep apnea, and night terrors)

insomnia

Difficulty in falling asleep or staying asleep

narcolepsy

overpowering urge to fall asleep that may occur while talking or standing up

sleep apnea

failure to breathe when asleep

night terrors

sudden arousal from sleep with intense fear accompanied by physiological reactions (occurs usually during 1st sleep cycle of the night)