The processes that organize information in the sensory image and interpret it as having been produced by properties of objects or events in the external, three-dimensional world.
The process by which stimulation of a sensory receptor gives rise to neutral impulses that result in an experience, or awareness, of conditions inside or outside the body.
The processes that put sensory information together to give the perception of a coherent scene over the whole visual field.
Identification and recognition
Two ways of attaching meaning to percepts.
In the processes of perception, the physical object in the world, as contrasted with the proximal stimulus, the optical image on the retina.
The optical image on the retina; contrasted with the distal stimulus, the physical object in the world.
The study of teh correspondence between physical simulation and psychological experience.
The minimum amount of physical energy needed to produce a reliable sensory experience; operationally defined as the stimulus level at which a sensory signal is detected half the time.
A graph that plots the percentage of detections of a stimulus (on the vertical axis) for each stimulus intensity (on the horizon axis).
A phenomenon in which receptor cells lose their power to respond after a period of unchanged stimulation; allows a more rapid reaction to new sources of information.
The systematic tendency as a result of non sensory factors for an observer to favor responding in a particular way.
Signal detection theory
A systematic approach to the problem of response bias that allows an experimenter to identify and separate the roles of sensory stimuli and the individuals criterion level in producing the final response.
The smaller physical difference between two stimuli that can still be recognized as a difference; operationally defined as the point at which the stimuli are recognized as different half of the time.
Just-noticeable difference (JDN)
The smallest difference between two sensations that allows them to be discriminated.
An assertion that the size of a difference threshold is proportional to the intensity of the standard stimulus.
Transformation of one form of energy into another; for example, light is transformed into neutral impulses.
Specialized cell that converts physical signals into cellular signals that are processed by the nervous system.
The opening at the front of the eye through which light passes.
The flexible tissue that focuses light on the retina.
The process by which the ciliary muscles change the thickness of the lens of the eye to permit variable focusing on near and distant objects.
The layer at the back of the eye that contains photo receptors and converts light energy to neutral responses.
Receptor cell in the retina that is sensitive to light.
One of the photoreceptors concentrated in the periphery of the retina that are most active in dim illuminations; rods do not produce sensation of color.
One of the photoreceptors concentrated in the center of the retina that are responsible for visual experience under normal viewing conditions for all experiences of color.
The gradual improvement of the eyes' sensitivity after a shift in illumination from light to near darkness.
Area of the retina that contains densely packed cones and forms the point of sharpest vision.
Nerve cell in the visual system that combines impulses from many receptors and transmits the results to ganglion cells.
Cell in the visual system that integrates impulses from many bipolar cells in a single firing rate.
One of the cells that integrate information across the retina; rather than sending signals toward the brain, horizontal cells connect receptors to each other.
One of the cells that integrate information across the retina; rather than sending signals toward the brain, amacrine cells link bipolar cells to other bipolar cells and ganglion cells to other ganglion cells.
The region of the retina where the optic nerve leaves the back of the eye; no receptors cells are present in this region.
The axons of the ganglion cells that carry information from the eye toward the brain.
The area of visual field to which a neuron in the visual system responds.
The dimension of color space that captures the qualitative experience of the color of light.
The dimension of color space that captures the purity and vividness of color sensations.
The dimension of color space that captures the intensity of light.
Colors opposite each other on the color circle; when additively mixed, they create the sensation of white light.
The theory that there are three types of color receptors that produce the primary color sensations of red, green and blue.
The theory that all color experiences arise from three systems, each of which includes two "opponent" elements (red versus green, blue versus yellow, and black versus white).
Sound quality of highness or lowness; primarily dependent on the frequency of the sound wave.
A perceptual dimension of sound influenced by the amplitude of a sound wave; sound waves in large amplitudes are generally experienced as loud and those with small amplitudes as soft.
The dimension of auditory sensation that reflects the complexity of a sound wave.
The primary organ of hearing; a fluid-filled coiled tube located in the inner ear.
A membrane in the cochlea that, when set into motion, stimulates hair cells that produce the neural effects of auditory stimulation.
The nerve that carries impulses from the cochlea to the cochlear nucleus of the brain.
The theory that different frequency tones produce maximum activation at different locations along the basilar membrane, with the result that pitch can be coded by the place at which activation occurs.
The theory that a tone produces a rate of vibration in the basilar membrane equal to its frequency, with the result that pitch can be coded by the frequency of the neural response.
An extension of frequency theory, which proposes that when peaks in a sound wave come too frequently for a single neuron to fire at each peak, several neurons fire as a group at the frequency of the stimulus tone.
The auditory processes that allow the spatial origins of environmental sounds.
The sense of smell.
The center where odor-sensitive receptors send their signals, located just below the frontal lobes of the cortex.
Chemical signal released by an organism to communicate with other members of the species; pheromones often serve as long-distance sexual attractors.
The sense of taste.
The skin senses that register sensations or pressure, warmth, and cold.
The sense that tells, how one's own body is oriented in the world with respect to gravity.
The sense concerned with bodily position and movement of the body parts relative to one another.
The body's response to noxious stimuli that are intense enough to cause, or threaten to cause, tissue damage.
A theory about pain modulation that proposes that certain cells in the spinal cord act as gates to interrupt and block some pain signals while sending others to the brain.
A state of focused awareness on a subset of teh available perceptual information.
A determinant of why people select some parts of sensory input for further processing; it reflects the choices made as a function of one's own goals.
A determinant of why people select some parts of sensory input for further processing; occurs when features of stimuli--objects in the environment--automatically capture attention, independent of the local goals of a perceiver.
A school of psychology that maintains that psychological phenomena can be understood only when viewed as organized, structured wholes, not when broken down into primitive perceptual elements.
The simplest form of apparent motion, the movement illusion in which one or more stationary lights going on and off in succession are perceived as a single moving light.
Binocular depth cue
Depth cue that uses information from both eyes.
The displacement between the horizontal positions of corresponding images in the two eyes.
The degree to which the eyes turn inward to fixate on an object.
A source of information about depth in which the relative distances of objects from a viewer that determine the amount of direction of their relative motion in the retinal image.
Monocular depth cue
Depth cue that uses information from only one eye.
The ability to retain an unchanging percept of an object despite variations in the retinal image.
The ability to perceive the true size of an object despite variations in the size of its retinal image.
The ability to perceive the true shape of an object despite variations in the size of the retinal image.
The tendency to perceive the whiteness, grayness, or blackness, of objects as constant across changing levels of illuminations.
An experience of stimulus pattern in a manner that is demonstrably incorrect but shared by others in the same perceptual environment.
Perceptual analyses based on the sensory data available in the environment; results of analysis are passed upward toward more abstract representations.
Perceptual processes in which information from an individual's past experience, knowledge, expectations, motivations, and background influence the way a perceived object is interpreted and classified.
Property of perceptual object that may have more than one interpretation.
A temporary readiness to perceive or react to a stimulus in a particular way.