Exam #4 Terms (Sensation and Perception/Consciousness and the Two-Track Mind) Flashcards
What is sensation?
The process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment.
What are sensory receptors?
Sensory nerve endings that respond to stimuli.
What is perception?
The process of organizing and interpreting sensory information, enabling us to recognize meaningful objects and events.
What is bottom-up processing?
Analysis that begins with the sensory receptors and works up to the brain’s integration of sensory information.
What is top-down processing?
Information processing guided by higher-level mental processes, as when we construct perceptions by drawing on our experience and expectation.
What is selective attention?
The focusing of conscious awareness on a particular stimulus.
What is inattentional blindness?
Failing to see visible objects when our attention is directed elsewhere.
What is change blindness?
Failing to notice changes in the environment; a form of inattentional blindness.
What is transduction?
Conversion of one form of energy into another. In sensation, the transforming of stimulus energies, such as sights, sounds, and smells, into neural impulses our brain can interpret.
What is psychophysics?
The study of relationships between the physical characteristics of stimuli, such as their intensity, and our psychological experience of them.
What is the absolute threshold?
The minimum stimulus energy needed to detect a particular stimulus fifty percent of the time.
What is 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.
What does subliminal mean?
Below one’s absolute threshold for conscious awareness.
What is the difference threshold?
The minimum difference between two stimuli required for detection fifty percent of the time. We experience the difference threshold as a just noticeable difference (or jnd).
What is priming?
The activation, often unconsciously, of certain associations, thus predisposing one’s perception, memory, or response.
What is Weber’s law?
The principle that, to be perceived as different, two stimuli must differ by a constant minimum percentage (rather than a constant amount). Light must differ by 8%, weight by 2%, and tone by 3%.
What is a perceptual set?
A mental predisposition to perceive one thing and not another.
What is extrasensory perception (ESP)?
The controversial claim that perception can occur apart from sensory input, including telepathy, clairvoyance, and precognition.
What is parapsychology?
The study of paranormal phenomena, including ESP and psychokinesis.
What is wavelength?
The distance from the peak of one light or sound wave to the peak of the next.
High frequency…
Low frequency…
…short wavelength (bluish colors)
…long wavelength (reddish colors)
Great amplitude…
Small amplitude…
…bright colors
…dull colors
What is hue?
The dimension of color that is determined by the wavelength of light; what we know as the color names blue, green, and so forth.
What is intensity?
The amount of energy in a light wave or sound wave, which influences what we perceive as brightness or loudness. Intensity is determined by the wave’s amplitude (height).
What is the cornea?
The eye’s clear, protective outer layer, covering the pupil and iris.
What is the pupil?
The adjustable opening in the center of the eye through which light enters.
What is the 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.
What is the lens?
The transparent structure behind the pupil that changes shape to help focus images on the retina.
What is the retina?
The light-sensitive inner surface of the eye, containing the receptor rods and cones plus layers of neurons that begin the processing of visual information.
What is accomodation?
The process by which the eye’s lens changes shape to focus on near or far objects on the retina.
What are 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.
What are 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.
What is the optic nerve?
The nerve that carries neural impulses from the eye to the brain.
What is a blind spot?
The point at which the optic nerve leaves the eye, creating a “blind” spot because no receptor cells are located there.
What is the fovea?
The central focal point in the retina, around which the eye’s cones cluster.
What is the Young-Helmholtz trichromatic (three-color) 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.
What is the opponent-process theory?
The theory that opposing retinal processes (red-green, blue-yellow, white-black) enable color vision.
What are feature detectors?
Nerve cells in the brain’s visual cortex that respond to specific features of the stimulus, such as shape, angle, or movement.
What is parallel processing?
Processing many aspects of a problem simultaneously; the brain’s natural mode of information processing for many functions, including vision.
What is a gestalt?
An organized whole. Gestalt psychologists emphasized our tendency to integrate pieces of information into meaningful wholes.
What is the figure-ground?
The organization of the visual field into objects (the figures) that stand out from their surroundings (the ground).
What is grouping?
The perceptual tendency to organize stimuli into coherent groups.
What is depth-perception?
The ability to see objects in three dimensions although the images that strike the retina are two-dimensional; allows us to judge distance.
What is the visual cliff?
A laboratory device for testing depth perception in infants and young animals.
What is a binocular cue?
A depth cue, such as retinal disparity, the depends on the use of two eyes.
What is retinal disparity?
A binocolar cue for perceiving depth. By comparing retinal images from the two eyes, the brain computes distance (stereoscopic vision).
What is a monocular cue?
A depth cue, such as interposition or linear perspective, available to either eye alone.
What is perceptual constancy?
Perceiving objects as unchanging even as illumination and retinal images change.