AP Psych - Chapter 4: Sensation and Perception
AP Psychology textbook vocabulary for Chapter 4: Sensation and Perception.
Terms in this set (70)
The process by which stimulation of a sensory receptor produces neural impulses that the brain interprets as a sound, visual image, odor, taste, pain, or other sensory image; represents the first series of steps in processing of incoming information.
A process that makes sensory patterns meaningful; draws heavily on memory, motivation, emotion, and other psychological processes.
Transformation of one form of energy into another - especially the transformation of stimulus information into nerve signals by the sense organs.
Loss of responsiveness in receptor cells after stimulation has remained unchanged for a while (as when a swimmer becomes adapted to the temperature of the water).
The amount of stimulation necessary for a stimulus to be detected. In practice, this means that the presence or absence of a stimulus is detected correctly half the time over many trials.
The smallest amount by which a stimulus can be changed and the difference be detected half the time.
Just noticeable difference (JND)
Same as the difference threshold: the smallest amount by which a stimulus can be changed and the difference be detected half the time.
This concept says that the size of a JND is proportional to the intensity of the stimulus; the JND is large when the stimulus intensity is high and is small when the stimulus intensity is low.
The magnitude of a stimulus can be estimated by the formula S = klogR, where S = sensation, R = stimulus, and k = a constant that differs for each sensory modulation; expresses the relationship between the actual magnitude of the stimulus and its perceived magnitude; an increase in physical magnitude of a stimulus progressively produces smaller increases in perceived magnitude.
Steven's power law
A law of magnitude estimation that is more accurate than Fechner's law and covers a wider variety of stimuli, namely pain and temperature. It is represented by the formula S = kl^a, where S = sensation, k = a constant, I = stimulus intensity, and a = a power exponent that depends on the sense being measured.
Signal detection theory
Explains how we detect "signals," consisting of stimulation affecting our eyes, ears, nose, skin, and other sense organs; says that sensation is a judgement the sensory system makes about incoming stimulation, which often occurs outside of consciousness, and depends on the characteristics of the stimulus, the background stimulation, and the detector. In contrast to older theories from psychophysics, it takes observer characteristics into account.
The thin, light-sensitive layer at the back of the eyeball; contains millions of photoreceptors and other nerve cells.
Light-sensitive cells (neurons) in the retina that convert light energy to neural impulses; mark the farthest point that light gets into the visual system.
Photoreceptors in the retina that are especially sensitive to dim light but not to color; rod-shaped.
Photoreceptors in the retina that are especially sensitive to colors but not to dim light; cone-shaped.
The tiny area of sharpest vision in the retina; most concentrated area of cones.
Cells that collect impulses from many photoreceptors and shuttle them onto the ganglion cells.
The bundle of neurons that carries visual information from the retina to the brain; made of the axons of the ganglion cells.
The point where the optic nerve exits the eye and where there are no photoreceptors; any stimulus that falls on this area cannot be seen.
A psychological sensation caused by the intensity of light waves.
Not a physical property of things in the external world - rather, it is a psychological sensation created in the brain from information obtained by the eyes from the wavelengths of visible light; also called hue.
The entire range of electromagnetic energy, including radio waves, X-rays, microwaves, and visible light.
The tiny part of the electromagnetic spectrum to which our eyes are sensitive.
The idea that colors are sensed by three different types of cones sensitive to light in the red, blue, and green wavelengths; explains the earliest stage of color sensation.
The idea that cells in the visual system process colors in complementary pairs, such as red or green or as yellow or blue; explains color sensation from the bipolar cells onward in the visual system.
Sensations that linger after the stimulus is removed; most are negative afterimages, which appear in reversed colors.
Typically a genetic disorder (although sometimes the result of trauma) that prevents an individual from discriminating certain colors; most common form is red-green blindness.
The number of cycles completed by a wave in a given amount of time, usually a second; usually expressed in cycles per second (cps) or hertz (Hz).
The physical strength of a wave; usually measured from peak (top) to valley (bottom) on a graph of the wave; defined in units of sound pressure or energy.
The outer ear.
The primary organ of hearing; a coiled tube in the inner ear, where sound waves are transduced into nerve messages.
A thin strip of tissue sensitive to vibrations in the cochlea; contains hair cells connected to neurons. When a sound wave causes the hair cells to vibrate, the associated neurons become excited. As a result, the sound waves are converted (transduced) into nerve activity.
A sensory characteristic of sound produced by the frequency of the sound wave.
An explanation of pitch perception that says that different places on the basilar membrane send neural codes for different pitches to the auditory cortex of the brain; accounts for high pitches (above 1000 Hz) only.
An explanation of pitch perception that says that neurons on the basilar membrane respond with different firing rates for different sound wave frequencies; accounts for frequencies below 5000 Hz (between 1000 and 5000 Hz, hearing is based on both place and frequency).
A sensory characteristic of sound produced by the amplitude (intensity) of the sound wave; measured in decibels (dB).
The quality of a sound wave that derives from the wave's complexity (combination of pure tones).
An inability to hear resulting from damage to structures of the middle or inner ear; most often a result of sound that has been too loud or some sort of trauma.
Nerve deafness (sensorineural deafness)
An inability to hear, linked to a deficit in the body's ability to transmit impulses from the cochlea to the brain, usually involving the auditory nerve or higher auditory processing centers.
The sense of body orientation with respect to gravity; closely associated with the inner ear, and, in fact, is carried to the brain on a branch of the auditory nerve.
The sense of body position and movement of bod parts relative to each other.
The sense of smell.
Chemical signals released by organisms to communicate with other members of their species; often used by animals as sexual attractants.
The sense of taste.
Sensory systems for processing touch, warmth, cold, texture, and pain.
An explanation for pain control that proposes we have a neural "gate" that can, under some circumstances, block incoming pain signals.
A response to a placebo (fake drug), caused by subjects' belief that they are taking real drugs.
The meaningful product of perception - often an image that has been associated with concepts, memories of events, emotions, and motives.
Cells in the cortex that specialize in extracting certain features of a stimulus.
Refers to the process used by the brain to combine (or "bind") the results of many sensory operations into a single percept. No one knows exactly how the brain does this - thus, it is one of the major unsolved mysteries in psychology.
Perceptual analysis that emphasizes the characteristics of the stimulus, rather than our concepts and expectations. "Bottom" refers to the stimulus, which occurs at step one of perceptual processing.
Perceptual analysis that emphasizes the perceiver's expectations, concept memories, and other cognitive factors, rather than being driven by the characteristics of the stimulus. "Top" refers to a mental set in the brain - which stands at the "top" of the perceptual processing system.
The ability to recognize the same object as remaining "constant" under different conditions, such as changes in illumination, distance, or location.
Stimulus patterns that cause the observer to form an incorrect perception of said pattern; become more likely when the stimulus is unclear, when information is missing, when elements are combined in unusually ways, or when familiar patterns are not apparent.
Images that are capable of more than one interpretation. There is no "right" way to see an ambiguous figure.
From a German word that means "whole" or "form" or "configuration;" believed that much of perception is shaped by innate factors built into the brain.
The part of a pattern that commands attention; the figure stands out against the ground.
The part of a pattern that does not command attention; the background.
The Gestalt principle that identifies the tendency to fill in gaps in figures and to see incomplete figures as complete.
Laws of perceptual grouping
The Gestalt principles of similarity, proximity, continuity, and common fate. These "laws" suggest how our brains prefer to group stimulus elements together to form a percept (Gestalt).
Law of similarity
The Gestalt principle that we tend to group similar objects together in our perceptions.
Law of proximity
The Gestalt principle that we tend to group objects together when they are near each other (proximity means nearness).
Law of continuity
The Gestalt principle that we prefer perceptions of connected and continuous figures to disconnected and disjointed ones.
Law of common fate
The Gestalt principle that we tend to group similar objects together that share a common motion or destination.
Law of Prägnanz
The most general Gestalt principle, which states that the simplest organization, requiring the least cognitive effort, will emerge as the figure; Prägnanz carries the idea of a "fully developed figure" - that is, our perceptual system prefers to see a fully developed Gestalt, such as a complete circle as opposed to a broken circle.
Information take in by both eyes that aids in depth perception, including binocular convergence and retinal disparity.
Information about depth that relies on the input of just one eye - includes relative size, light and shadow, interposition, relative motion, and atmospheric perspective.
The view that perception is primarily shaped by learning (or experience), rather than by innate factors.
Readiness to detect a particular stimulus in a given context.