Unit 1 part 3 vocab

sleep

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 that occur on a 24-hour cycle

REM sleep

rapid eye movement sleep; recurring sleep state during which vivid dreams commonly occur (aka "paradoxical sleep" since muscles are relaxed but other body systems are active)

alpha waves

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/feeling of falling/floating weightlessly, while transitioning into sleep

delta waves

large, slow brain waves associated with deep sleep

suprachiasmatic waves

pair of cell clusters in hypothalamus that controls circadian rhythm; response to light: SCN adjusts melatonin production in order to modify feelings of slepeiness

insomnia

recurring problems in falling or staying asleep

narcolepsy

sleep disorder characterized by uncontrollable sleep attacks; affected person may lapse directly into REM sleep, often at inopportune times

sleep apnea

sleep disorder characterized by temporary cessations of breathing during sleep + repeated momentary awakenings

REM sleep behavior disorder

a sleep disorder in which normal REM paralysis does not occur; instead, twitching, talking, or kicking/punching may occur, often acting out of one's dream

dream

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

REM rebound

the tendency for REM sleep to increase following REM sleep deprivation

sensation

the process by which our sensory receptors + nervous system receive + represent stimulus energies from our environment

sensory receptors

sensory nerve endings that respond to stimulus

perception

process by which our brain organizes + interprets sensory information, enabling us to recognize objects + events as meaningful

bottom-up processing

information processing that begins with the sensory receptors + 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 + expectations

transduction

conversion of one form of energy into another; in sensation, transformation of physical energy to neural impulses the brain can interpret

psychophysics

study of relationships between physical characteristics of stimuli + our psychological experience of them

absolute threshold

minimum stimulus energy needed to detect a particular stimulus 50% of the time

signal detection theory

theory predicting how + when we detect the presence of a faint stimulus amid background stimulations; assumes no single absolute threshold + detections depend on person's experience

subliminal

below one's absolute threshold for conscious awareness

priming

activation, often unconsciously of certain associations, thus predisposing one's perceptions, memory, or response

difference threshold

the minimum difference between two stimuli required for detection 50% of the time

weber's law

the principle that, to be perceived as different, two stimuli must differ by a constant minimum percentage

sensory adaptation

diminished sensitivity as a consequence of constant stimulation