AP Review #6- Sensation and perception

feature detection theory

Proposed by Hubel and Wiesel, theory of perception that proposes that we have specialized cells in the visual cortex, feature detectors, that fire only when they receive input that indicates we are looking at a particular shape, color, angle, or other visual feature.

Parts of the eye

cornea, iris, pupil, lens, retina

place theory of hearing

the theory that different areas of the basilar membrane respond to different frequencies

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.

just noticeable difference (JND)

the threshold at which one can distinguish two stimuli that are of different intensities, but otherwise identical Weber's and Feschner's laws attempt to measure the detectable ratio between the original and new stimulus.

habituation

For sensation and perception: The tendency of the brain to ignore an unchanging stimulus. For example, you can't see your nose even though its in your visual field. In developmental psychology: As infants gain familiarity with repeated exposure to a visual stimulus, their interest wanes and they look away sooner.

Gestalt principles of organization

The organizing principles of perception proposed by the Gestalt psychologists. These principles include the laws of proximity, similarity, closure, continuation, and common fate.

light and dark adaptation

The process by which the eyes become more sensitive to light in the dark and less sensitive to light, in the light. Involves chemical transfer from cones to rods.

bottom-up processing

analysis that begins with the sensory receptors and works up to the brain's integration of sensory information

monocular depth cues

aspects of a scene that yield information about depth when viewed with only one eye. For example: texture-gradient, interposition, height, relative size, linear perspective

binocular depth cues

clues about distance based on the differing views of the two eyes. For example retinal disparity

top-down processing

information processing guided by higher-level mental processes, as when we construct perceptions drawing on our experience and expectations

perceptual constancy

perceiving objects as unchanging even as illumination and retinal images change. For example size constancy, color constancy (the black or blue dress), or shading constancy.

sensory adaptation

tendency of sensory receptor cells to become less responsive to a stimulus that is unchanging. Example: getting used to the temperature of a hot tub, or adjusting to the unique smell of a classroom.

absolute threshold

the minimum stimulation needed to detect a particular stimulus 50 percent of the time

parallel processing

the processing of many aspects of a problem simultaneously; the brain's natural mode of information processing for many functions, including vision. Contrasts with the step-by-step (serial) processing of most computers and of conscious problem solving.

rods and cones

the sensory receptors in the retina that are stimulated by the light that comes into the eye and sends that signal to the brain via the optic nerve. Rods are stimulated in low light and see the grey scale, Cones need high light and see color, 3 types: red, green, and blue. Cones are clustered in the center of the retina (fovia) Rods are located in the outer ring (periphery) of of the retina

opponent-process theory

the theory that opposing retinal processes (red-green, yellow-blue, 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. Example American Flag Illusion

trichromatic theory

theory of color vision that proposes three types of cones: red, blue, and green. Also known as Young-Helmholtz Theory

frequency theory

theory of pitch that states that pitch is related to the speed of vibrations in the basilar membrane