Unit 2: Part 2 + Unit 3: Sensation and Perception Flashcards
sleep
a periodic, natural loss of consciousness — as distinct from unconsciousness resulting from a coma, general anesthesia, or hibernation.
circadian rhythm
our biological clock; regular bodily rhythms (for example, of temperature and wakefulness) that occur on a 24-hour cycle.
REM sleep
rapid eye movement 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.
NREM sleep
non-rapid eye movement sleep; encompasses all sleep stages except for REM sleep.
hallucinations
false sensory experiences, such as seeing something in the absence of an external visual stimulus.
hypnagogic sensations
bizarre experiences, such as jerking or a feeling of falling or floating weightlessly, while transitioning to sleep.
delta waves
the large, slow brain waves associated with the deep sleep of NREM-3.
suprachiasmatic nucleus (SCN)
a pair of cell clusters in the hypothalamus that controls circadian rhythm. In response to light, the SCN causes the pineal gland to adjust melatonin production, thus modifying our feelings of sleepiness.
insomnia
recurring problems in falling or staying asleep.
Chronic tiredness. Reliance on sleeping pills and alcohol, which reduce REM sleep and lead to tolerance — a state in which increasing doses are needed to produce an effect.
narcolepsy
a sleep disorder characterized by uncontrollable sleep attacks. The sufferer may lapse directly into REM sleep, often at inopportune times.
Risk of falling asleep at a dangerous moment. Narcolepsy attacks usually last less than 5 minutes, but they can happen at the worst and most emotional times. Everyday activities, such as driving, require extra caution.
sleep apnea
a sleep disorder characterized by temporary cessations of breathing during sleep and repeated momentary awakenings.
Fatigue and depression (as a result of slow-wave sleep deprivation). Associated with obesity (especially among men).
night terrors
a sleep disorder characterized by high arousal and an appearance of being terrified; unlike nightmares, night terrors occur during NREM-3 sleep, within two or three hours of falling asleep, and are seldom remembered.
Doubling of a child’s heart and breathing rates during the attack. Luckily, children remember little or nothing of the fearful event the next day. As people age, night terrors become more and more rare.
dream
a sequence of images, emotions, and thoughts passing through a sleeping person’s mind
manifest content
according to Freud, the symbolic, remembered story line of a dream (as distinct from its latent, or hidden, content).
latent content
according to Freud, the underlying meaning of a dream (as distinct from its manifest content).
REM rebound
the tendency for REM sleep to increase following REM sleep deprivation.
depressants
drugs (such as alcohol, barbiturates, and opiates) that reduce neural activity and slow body functions.
alcohol use disorder
(popularly known as alcoholism) alcohol use marked by tolerance, withdrawal, and a drive to continue problematic use.
barbiturates
drugs that depress central nervous system activity, reducing anxiety but impairing memory and judgment.
opiates
opium and its derivatives, such as morphine and heroin; depress neural activity, temporarily lessening pain and anxiety.
stimulant
drugs (such as caffeine, nicotine, and the more powerful cocaine, amphetamines, methamphetamine, and Ecstasy) that excite neural activity and speed up body functions.
nicotine
a stimulating and highly addictive psychoactive drug in tobacco.
cocaine
a powerful and addictive stimulant derived from the coca plant; produces temporarily increased alertness and euphoria.
methanphetamine
a powerfully addictive drug that stimulates the central nervous system, with accelerated body functions and associated energy and mood changes; over time, appears to reduce baseline dopamine levels.
amphetamines
drugs, such as methamphetamine, that stimulate neural activity, causing accelerated body functions and associated energy and mood changes.
ecstasy(MDMA)
a synthetic stimulant and mild hallucinogen. Produces euphoria and social intimacy, but with short-term health risks and longer-term harm to serotonin-producing neurons and to mood and cognition.
hallucinogens
psychedelic (“ mind-manifesting”) drugs, such as LSD, that distort perceptions and evoke sensory images in the absence of sensory input.
near-death experience
an altered state of consciousness reported after a close brush with death (such as cardiac arrest); often similar to drug-induced hallucinations.
LSD
a powerful hallucinogenic drug; also known as acid (lysergic acid diethylamide).
THC
the major active ingredient in marijuana; triggers a variety of effects, including mild hallucinations.
sensation
the process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment.
sensory receptors
sensory nerve endings that respond to stimuli.
perception
the process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events.
bottom-up processing
analysis that begins with the sensory receptors and works up to the brain’s integration of sensory information.
top-down processing
information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experience and expectations.
selective attention
the focusing of conscious awareness on a particular stimulus.
inattentional blindness
failing to see visible objects when our attention is directed elsewhere.