AP Psychology unit 5-Sensation and Perception Psych Vocab

Sensation

The process by which our sensory receptors and nervous system receive and represent stimulus energies from our environment. (converts it into neural signals).

Perception

The process of organizing, selecting, and interpreting sensory information enabling us to recognize meaningful objects and events.

Bottom-up Processing

the entry level analysis of sensations. Also called feature analysis. It works up to the brain’s integration of sensory information.

Top-down Processing

is the analysis of sensation drawing on experience and expectations. Our experiences create schemata, which are mental representations of how we expect the world to be, Schemata can create a perceptual set, which is predisposition to perceive something in a certain way. Guided by higher level mental processes.

Psychophysics

the study of relationships between the physical characteristics of stimuli, such as their intensity, and our psychological experience of them.

Absolute Threshold

the minimum stimulus energy needed to detect a particular stimulus 50% of the time. The weakest amount of stimulus that people that a person can detect 50% of the time.

Difference Threshold

The minimum difference between two stimuli required for detection 50% of the time. We experience the ________ _______ as a just noticeable difference.

Subliminal Threshold

Below ones absolute threshold for conscious awareness.

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).

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 the detection depends partly on a person’s experience, expectations, motivation, and alertness.

Sensory Adaptation

Diminished sensitivity as a consequence of constant stimulation

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.

Perceptual Set

a mental predisposition to perceive one thing and not another.

Sensory Receptors

sensory nerve endings that respond to stimuli

Priming

the activation, often unconsciously, of certain associations, thus predisposing one’s perceptions, memory, or response.

wavelength of lightwave

the distance from one light or sound wave to the peak of the next.

amplitude of a lightwave

the distance from the peak of one light or sound wave to the pea of the next. Height of the wave,influences brightness in visual perception.

cornea

Light enters through the ______, a protective covering. Contributes most of the eyes focusing power.

iris

the colored muscle that expands and contracts to change the size of the opening (pupil) for the light.

pupil

light goes through the _____, which can open and close to allow more or less light in.

lens

focuses the light rays on the retina

retina

the light sensitive inner surface of the eye, containing the receptor rods and cone plus layers of neurons that begin the processing of visual information.

accommodation

the process by which the yes lens changes shape to focus near or far objects on the retina

fovea

the central focal point in the retina, around which the eyes cones cluster

optic nerve

the nerve that carries neural impulses from the eye to the brain

thalamus

the sensory processing center of the brain. Processes every sense except smell

blindspot

the point at which the optic nerve leaves the eye creating a “blind” spot because there are no receptor cells located there.

nearsighted

a condition in which nearby objects are seen more clearly than distant objects

farsighted

a condition in which faraway objects are seen more clearly than near objects

rods

retinal receptors that detect block, 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. Detect fine detail and give rise to color sensations

feature detectors

nerve cells in the brain that respond to specific features of the stimulus, such as shape, angles or movement.

parallel processing

processing many aspects of a problem simultaneously; the brain’s natural made of information processing for many functions, including vision.

young-helmoltz trichromatic theory

the theory that the retention 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.

color blindness

the lack in function of certain light receptors (cones) within the retina (most common red-green)

opponent process theory

the theory that opposing retinal processes (red-green, yellow-blue, white-black)) marble color vision. For example, some cells are stimulated by green and inhibited by red; others are stimulated by red and inhibited by green.

gestalt psycholog

the organized whole. Emphasized our tendency to integrate pieces of information into meaningful wholes.

figure-ground

an organization of the visual field into objects (the figure) that stand out form the surroundings (the ground)

depth perception

the ability to see objects in three dimensions although the images that strike the retina is 2 dimensions. Allows us to judge distance.

visual cliff

a laboratory devise for testing depth perception in infants and young animals.

monocular cues

a depth cue, such as interposition or linear persepctive-available to either eye alone

binocular cues

a depth cue, such as retinal disparity that depends on the use of the two eyes

retinal disparity

a binocular cue for perceiving depth. By comparing retinal images from the two eyes, the brain computes distance-the greater the disparity(difference) between the two images, the closer the object.

relative size

if we amuse two objects are similar in size, most people perceive the one that casts the smallest retinal image as further away.

interposition

if one object partially blocks our view of another, we perceive it as closer.

relative height

we perceive objects higher in our field of vision as farther away.

relative motion

as we move, objects that are actually stable may appear to move.

linear perspective

parallel lines appear to meet in the distance. The sharper the angle of the convergence, the greater the perceived distance.

light and shadow

shading provides a sense of depth consistence with our assumption that light comes from above.

phi phenomenon

an illusion of movement created when two or more adjacent lights blink on and off in quick succession.

perceptual constancy

perceiving objects and unchanging (having constant color, brightness, shape, and size even as illumination and retinal images change

perceptual adaptation

the ability to adjust to changed sensory inputs, including an artfully displaced or even inverted visual field.

perceptual set

a temporary readiness to perceive certain objects or events rather than others. For example, a person driving a car has a perceptual set to identify anything in the car or on the road that might affect his or her safety

dichotic listening

an experimental technique where different messages are transmitted into each ear of a subject to test “selective attention” or the ability to concentrate on one messages to the exclusion of the other.

hue

the dimension of color that is determined by the wavelength of light is known as____. The quality by which we distinguish one color from another, as a red from a yellow, a green, a blue or a purple.

intensity

the amount of energy in a light or sound wave, which we perceive as brightness or loudness.

tectum

is responsive for auditory and visual processing and control of eye movements.

grouping

the perceptual tendency to organize stimuli into coherent groups.