Unit 1 Part 1 B Terms Flashcards
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 deep sleep
Suprachiasmatic nucleus (SCN)
A pair of cell clusters in the hypothalamus that controls circadian rhythm
Insomnia
Recurring problems in falling or staying asleep
Narcolepsy
A sleep disorder characterized by uncontrollable sleep attacks. The affected person 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
REM behavior disorder
A sleep disorder involving motor activity during REM sleep, which typically includes a physical enactment of dream sequences
Dream analysis
a technique, originally used in psychoanalysis but now also used in some other psychotherapies, in which the content of dreams is interpreted to reveal underlying motivations or symbolic meanings and representations
Sigmund Freud
Austrian neurologist; invented and developed psychoanalysis
REM rebound
The tendency for REM sleep to increase following REM sleep deprivation
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 by which our brain organizes and interprets sensory information, enabling us to recognize objects and events as meaningful
Bottom up processing
Information processing 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
Transduction
Conversion of one form of energy into another. In sensation, the transforming of physical energy, such as sights, sounds, and smells, into neural impulses the brain can interpret
Glutamate
Serves as the predominant excitatory neurotransmitter in the brain. Glutamate plays a critical role in cognitive, motor, and sensory functions
Absolute threshold
The minimum stimulus energy needed to detect a particular stimulus 50 percent of the time
Signal detection theory
A theory predicting how and when we detect the presence of a faint stimulus (signal) amid background stimulation (noise). Assumes there is no single absolute threshold and that detection depends partly on a person’s experience, expectations, motivation, and alertness
Hue
The dimension of color that is determined by the wavelength of light
Intensity
The amount of energy in a light wave or sound wave, which influences what we perceive as brightness or loudness; determined by the wave’s amplitude
Cornea
The eye’s clear, protective outer layer, covering the pupil and iris
Pupil
The adjustable opening in the center of the eye through which light enters
Iris
A ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening
Lens
The transparent structure behind the pupil that changes shape to help focus images on the retina
Retina
The light-sensitive back inner surface of the eye, containing the receptor rods and cones plus layers of neurons that begin the processing of visual information
Acommodation
In sensation and perception, the process by which the eye’s lens changes shape to focus images of near or far objects on the retina
Rods
Retinal receptors that detect black, white, and gray, and are sensitive to movement; necessary for peripheral and twilight vision, when cones don’t respond
Cones
Retinal receptors that are concentrated near the center of the retina and that function in daylight or in well-lit conditions. Cones detect fine detail and give rise to color sensations
Optic nerve
The nerve that carries neural impulses from the eye to the brain
Blind spot
The point at which the optic nerve leaves the eye, creating a “blind” spot because no receptor cells are located there
Fovea
The central focal point in the retina, around which the eye’s cones cluster
Trichromatic theory
The theory that the retina contains three different types of color receptors — one most sensitive to red, one to green, one to blue — which, when stimulated in combination, can produce the perception of any color
Opponent process theory
The theory that opposing retinal processes (red-green, blue-yellow, white-black) enable color vision. For example, some cells are stimulated by green and inhibited by red; others are stimulated by red and inhibited by green
Feature detectors
Nerve cells in the brain’s visual cortex that respond to specific features of the stimulus, such as shape, angle, or movement
Audition
The sense or act of hearing
Frequency
The number of complete wavelengths that pass a point in a given time
