3. The Visual Perception System Flashcards
Sensation
Process by which our sense organs and receptors detect and respond to sensory information that stimulates them
Perception
The process by which we give meaning to sensory information, resulting in our personal interpretation of that information.
Visual perception system
Consists of the complete network of physiological structures involved in vision
Cornea
A transparent, convex-shaped covering which protects the eye and helps to focus light rays onto the retina
Aqueous humour
a watery fluid which helps to maintain the shape of the eyeball and provides nutrients and oxygen to the eye and also carries away waste products
Pupil
An opening in the iris that helps to control the amount of light entering the eye
Iris
a ring of muscles which expand and contract to change the size of the pupil and control the amount of light entering the eye.
Lens
focuses light onto the retina and changes shape according to the distance of the object being viewed
Ciliary muscles
Muscles expand and contract, enabling the lens to automatically bulge to focus nearby objects onto the retina.
Vitreous Humour
Jelly-like substance which helps to maintain the shape of the eyeball and helps focus light.
Retina
Receives and absorbs light also processing light. Contains photo-receptors (cones/rods)
Optic-nerve
Sends information from retina to the brain (visual cortex)
Rods
A photoreceptor that responds to low levels of light - responsible for night vision
Cones
A photoreceptor that responds to hight levels of light - Responsibly for vision in well lit conditions.
Stages of Visual Perception
Reception - Transduction - Transmittion - Selection - Organisation - Interpretation
Reception
Process by which the eye receives incoming light from the external environment and focuses it onto the retina where an image of the visual stimulus is captured.
Transduction
Process by which the photoreceptors change electromagnetic energy into electrical impulses which can travel along the optic nerve to the brain
Organisation
Involves assembling or arranging the features of a visual image in a meaningful way.
Interpretation
Process of assigning meaning to visual information so that we can understand what we are looking at
Transmission
Involves sending information in the form of electrical impulses along the optic nerve to the brain
Visual Perception Principles
Are rules that we apply to visual information to assist our organisation and interpretation in consistent and meaningful ways.
Gestalt Principles
Refer to the ways in which we organise the features of a visual scene by grouping them to perceive a whole, complete form
Figure-Ground organisation
Organise visual information by perceptually dividing a visual scene into a figure which stands out from the ground
Closure
Refers to the perceptual tendency to mentally ‘close up,’ fill in or ignore gaps in a visual image and perceive objects as a whole
Similarity
Involves the tendency to perceive parts of a visual image that have similar features - such as size, shape, texture and colour
Proximity
The tendency to perceive part of a visual image which are positioned close together as belonging together in a group
Depth Principles
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