Visual perception Flashcards
list the gestalt principals:
-figure-ground
-closure
-similarity
-proximity
what is figure-ground?
the process of separating the figure from the ground with a perceived or actual line, this is called a contour line
what is closure?
refers to the process of when looking at an object with a gap being able to close it up to perceive objects as complete
what is similarity?
involves the tendency to perceive parts of an image with similar features to another image and group them into the ‘same’ category, as a group or whole
what is proximity?
the tendency to perceive closely placed items as belonging in a group
what is involved in the process of visual perception?
-reception
-transduction
-transmission
-interpretation
what is reception?
our sensory organs and receptors detect and respond to sensory information (physiological process)
what is transduction?
the process where the sensory message is converted into a chemical message to be transported
what is transmission?
once the message has been converted into a different form it then proceeds to travel from neuron to neuron
what is interpretation?
once the message is organised correctly, the brain will interpret the meaning of the message
what are the two photoreceptors?
rods and cones
what are the features of rods?
-125 million per eye
-periphery of retina
-work at nights
-black and white vision
-peripheral vison
what are the features of cones?
-6 million per eye
-centre of retina
-works during the day
-coloured vision
-high detail and accuracy
what are monocular depth cues?
-accommodation
-relative size
-linear perspective
-interposition
-height in the visual field
-texture gradient
what are binocular depth cues?
-convergence
-retinal disparity
define monocular and binocular depth cues
monocular:
use of one eye
binocular:
use of two eyes
what is accommodation?
the process of the eye shortening and bulging to focus on an object and expanding and flattening to look at an object further away
what is relative size?
the tendency to perceive the object that produces the largest image on the retina as closer and the object that produces a smaller image is further away
what is linear perspective?
is the apparent conversion of parallel lines in the distance
what is interposition?
also known as overlap, when one object partially covers another creating the appearance that the object it is covering is further away
what is height in the visual field?
refers to the location of objects in our visual field, whereby objects that are located closer to the horizon are perceived as being more distant than objects located further from the horizon.
what is retinal disparity?
refers to the very slight difference in the location of the visual images on the retinas, which enables us to make judgements about the distance of an object from the viewer.
what is convergence?
involves the brain detecting and interpreting depth or distance (up to 6 metres) from changes in tension in the eye muscles when the two eyes turn inwards to focus on nearby objects.
what are perceptual constancies?
refers to the tendency to perceive a visual stimulus as stable and unchanging despite any changes that occur on the retina
