psych

Gestalt psych

perception relies on the bigger picture and not the smaller elements

visual capture

when vision competes w other sentences, it usually wins

grouping

the perceptual tendency to organize stimuli into coherent groups

grouping principles

• proximity- united people & seperated groups

• similarity- rows w diff shapes

• continuity-

• closure

• connectedness

depth perception

• ability to see objects in 3 dimensions

• allows us to judge distance

visual cliff

a laboratory device for testing depth perception in infants and young animals

monocular cues

require one eye to see

binocular cue

require two eyes to see

retinal disparity

images from two eyes differ

convergence

when two eyes move inward (toward the noise) to see near objects and outwards (away from the noise) to see far away objects

relative size

if two objects are similar in size, we perceive the one that casts a smaller retinal image to be farther away

interposition

closer object blocks distant object

relative clarity

hazy object seen as more distant

monocular cues

indistinct texture signals an increasing distance

relative motion

objects closer to a fixation point move faster and n opposing direction to those objects that are farther away from a fixation point moving slower and in the same direction

linear perspective

parallel lines such as railroad tracks appear to converge in the distance, the more the lines converge, the greater their perceived distance

light and shadow

nearby objects reflect more light into our eyes than more distant objects. given two identical objects, the dimmer one appears to be farther away

phi phenomenon

when lights flash a certain speed they tend to present illusions of motion

motion perception

when something travels far away, it decreases in size and when it travels closer, it increases in size

perceptual constancy

perceiving objects as unchanging even as illumination and retinal image change

size constancy

stable size perception amid changing size of the stimuli

color constancy

perceiving familiar objects as having consistent color even when changing illumination filters reflected by the object

ponzo illusion

converging lines indicate that top line is farther away than bottom line

perceptual adaptation

visual ability to adjust to an artificially displaced visual field

perceptual set

schemas

concepts that organize and interpret unfamiliar information

bottom up processing

what we actually see/ hear, then making sense of it in the brain (starts w/ sensation)

top down processing

what we expect, social/ context clues determine the meaning (starts w/ perception)

psychophysics

study of the relationship between physical characteristics of stimuli and our psychological experience w/ them (light- brightness)

absolute threshold

the minimal amount of sensory stimulation needed for a sensation to occur

signal detection theory

predicts how and when we detect the presence of a faint stimulus signal amid background noise

difference threshold

minimum difference between two stimuli required for detection fifty percent of the time

accommodation

involves body changing ( eyes adjusting to light )

adaptation

literally our brains don’t attend to things that stay the same

transduction

converting one form of energy to another

phototransduction

conversion of light energy into neural impulses that the brain can understand

wavelength

hue/color

intensity

brightness

saturation

purity

hue

dimension of color determined by the wavelength of the light

wavelength

distance from the peak of one wave to the peak of the next

intensity

amount of energy in a wave determined by the amplitude

acuity

the sharpness of vision

cornea

the outer covering of the eye

pupil

adjustable opening in the center of the eye

iris

a ring of muscle that forms the colored portion of the eye around the pupil and controls the size of the pupil opening

lens

transparent structure behind the pupil that changes shape to focus images on the retina

accommodation

the process by which the eye lens changes shape to help focus near oor far objects on the retina

nearsightedness

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

farsightedness

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

retina

back of eyeball, where image is protected

optic nerve

carries neural impulses from the eye to the brain

blind spot

point where the optic nerve leaves the eye because there are no receptor cells located

fovea

central point in the retina around which eye cones cluster

rods

• peripheral retina

• detect black white and grey

• twilight or low light

cones

• near center of retina

• fine detail and color vision

• daylight or well lit conditions

feature detectors

cells that see certain aspects of the future

parallel processing

simultaneous processing of several aspects of a problem

trichromactic theory

helmholtz suggests that the retina should contain 3 receptors that are sensitive to red, blue, green

addition of colors

if three primary colors (light) are mixed the resulting is white