ch 5 influences on visual perception Flashcards
accommodation
the process by which the ciliary muscles of the eye change the curvature of the lens to focus an image on the retina
achromotopsia
a lack of cone vision that causes people to see only black, white and grey
age-related macular degeneration
a build-up of grainy deposits in the centre of the retina causing deterioration of central vision
binocular depth cues
depth cues that use both eyes to gauge distance and space
camouflage
where the gestalt principle of figure-ground is used to blend the contour of the figure (which usually stands out) against the ground (background), making it more difficult to see
cataracts
cloudy spots in the lens that cause vision to become blurred when protein in the lens break down
closure
when an object is perceived as being whole despite actually being incomplete
colour vision deficiency
a genetically inherited disorder affecting how people perceive colour
congenital visual disorders
visual disorder present at brith
convergence
a binocular cue for depth perception: the automatic turning of the eyes inwards as we watch an object approaching
depth perception
the ability to accurately judge three dimensional space and distance, using cues in the environment
figure-ground organisation
a gestalt principle of perceptual organisation wherein images are organised into the central object of attention (figure) and a background (ground)
floaters
clumps of matter that appear as small specks or spot in central vision
Gestalt principles of visual perception
used to organised and interpret perceptual stimuli: including figure-ground organisation, closure, similarity and proximity
glaucoma
a disease affecting the optic nerve that interferes with the transmission of peripheral visual information to the brain
height in the visual field
a monocular depth cue that shows depth by portraying objects further away as being close to the horizon
inherited visual disorders
visual disorders passed down from parents to children due to genetic factors
interposition
is based on the partial blocking or obscuring of one object by
another.
linear perspective
a monocular depth cue that parallel lines appear to converge as they retreat into the distance
monocular depth cues
depth cues that use one eye independently or both eyes together to gauge distance and space
perceptual constancies
the tendency to maintain a stable perception of a stimulus, although the properties of the image on the retina may change
perceptual set
a predisposition to attend to certain aspects of the visual scene, or to interpret stimuli in a particular way according to certain preconceptions
pictorial depth cues
a monocular depth cue used by artists to create a three-dimensional perception of something that exists on a two-dimensional surface
presbyopia
a condition that develops as the lens loses elasticity and causes difficulties in focusing on objects that are close
proximity
the individual parts of a stimulus pattern are close together, allowing those parts to be perceived visually as a whole
relative size
perceive the object producing the largest retinal image as being the nearest, and the object producing the smallest retinal image as being the farthest
retinal disparity
the binocular depth cue that arises as the brain compares and contrasts the two slightly different images obtained because of the distance between the two eyes
retinis pigmentosa
a genetic degenerative disease affecting the retina
shape constancy
an object is perceived to maintain its known shape despite the changing perspective from which it is observed
similarity
the principle that elements that are similar in appearance will tend to be seen as a unit
size constancy
the constant perception of an object’s size, even though the size of the image on the retina alters as the object moves nearer to or further from us
texture gradient
texture in the foreground is seen in finer detail than the further away
