Psychology Chapter 6

selective attention

focusing of conscious awareness on a particular stimulus, as in cocktail party effect

perceptual set

a mental predisposition to perceive one thing and not another; determined by our schemas and experiences

retinal disparity

a binocular cue for perceiving depth; by comparing images from each eye, the brain computes distance; the greater the difference between two images the closer the object

texture gradient

a monocular cue; a gradual change from course, distinct texture to fine, indistinct textures signals increasing distance

relative motion

a monocular cue; as we move, objects that are stationary appear to move; the closer the object, the faster it appears to move

interposition

a monocular cue; if one object partially blocks the view of another, we perceive it as closer

relative size

a monocular cue; if we assume two objects are similar in size we perceive the one that casts the smaller retinal image as farther away

relative clarity

a monocular cue; light from distant objects passes through more atmosphere therefore they are perceived as hazy and farther away than sharp, clear objects

light and shadow

a monocular cue; nearby objects reflect more light to our eyes, dimmer objects seem farther away (assuming light comes from above)

relative height

a monocular cue; objects higher in our field of vision are perceived as farther away; causes the illusion that taller objects are longer than shorter objects

Linear perspective

a monocular cue; parallel lines such as RR tracks, seem to converge with distance; the greater the convergence, the greater the distance perceived

proximity

a rule for grouping; tendancy to group nearby objects figures together

telepathy

a type of ESP involving mind to mind communication

precognition

a type of ESP involving perceiving future events

clairvoyance

a type of ESP involving perceiving remote events, for example sensing that your friends house is burning down

change blindness

after being distracted and refocusing on a particular stimulus, change in stimulus during distraction period goes undetected

relative luminance

amount of light an object reflects relative to surroundings

phi phenomenon

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

gestalt

an organized whole; tendancy to integrate pieces of information into meaningful wholes

claims of ESP

astrological predictions, psychic healing, communication with dead, out of body experiences

convergence

binocular cue for perceiving depth; the estent to which the eyse converge inward when looking at an object; the greater the inward strain, the closer the object

stroboscopic movement

brain perceives continuous movement in rapid series of slightly varying images

extrasensory perception (ESP)

controvercial claim that perception can occur apart from sensory input; said to include telepathy, clairvoyance and precognition

monocular cues

depth cues such as interposition, relative size, and linear perspective available to each eye alone

binocular cues

depth cues such as retinal disparity and convergence that depend on use of two eyes

Muller-Lyer illusion

distance determines length; lines farther away appear to be bigger than lines close to us

inattentional blindness

failing to see visible objects when our attention is directed elsewhere

perceptual adaptation

in vision, the ability to adjust an artificially displaced or even inverted visual field

visual cliff

labratory device for testing depth perception in infants and young animals

lightness constancy

objects are perceived as having constant lightness despite illumination variations

figure-ground

organization of visual field into objects (figures) that stand out from surroundings (ground)

size constancy

perceive objects as having constant size even as distance changes

shape constancy

perceived shape can appear as staying consistant when angle is changes

perceptual constancy

perceiving objects as unchanging (in lightness, color, shape, size) as illumination and retinal images change; relating to top-down processing)

Grouping

perceptual tendancy to organize stimuli into coherant groups; has 5 rules

Human factors psychologists

psychologists who explore how people and machines interact, and how machines and physical environments can be made safe and easy to use; help design appliances, work settings to fit natural perceptions

problems with ESP

rejects our understanding that we are creatures whose minds are tied to our physical brains, and our belief that perceptual experiences of the world are built on sensations

psychokinesis

related to ESP; mind over matter principle; for example levitating a table, influencing a roll of dice

closure

rule for grouping; tendancy to fill in gaps to create complete whole objects

similarity

rule for grouping; tendancy to group figures together that are similar

connectedness

rule for grouping; tendancy to perceive connected, similar figures as 1 unit

continuity

rule for grouping; tendancy to perceive smooth, continuous patterns

motion perception of objects

shrinking objects are perceived to be retreating, enlarging objects appear to be approaching; large objects appear to move slower than small objects

visual capture

tendancy for vision to dominate other senses

depth perception

the ability to see objects in 3D although the images that strike our retina are 2D; allows us to judge distance

pop-out

when distinct stimulus pops out and draws our attention

change deafness

when focused on repeating a list, change in individual speaking goes unnoticed

moon illusion

when the moon is closer to the horizon it looks 50 percent larger