How Do We See Flashcards
What is linear perspective?
Parallel lines that seem that they are going to meet in the distance
What is height in plane?
Objects closer to horizon are perceived to be further away
What is texture gradient?
Detailed patterns are perceived to be closer
What is Relative size?
Smaller objects are perceived to be further away than larger objects
What is superimposition?
Hidden objects are further away that the object that is covering it
What are the rods in your eye
Light sensitive cells in the retina that respond even in dim light
Detect light
What are the cones in your eye
Light sensitive cells in the retina that can detect colour
Only work in bright light
What is the optic nerve
A bundle of nerve cells that leads out from the retina, it carries info from rods and cones to the brain
What is perception
The way your brain makes sense of the visual image detected by the eyes
What is the blind spot
The area of the retina where the optic nerve leaves, has no rods or cones so cannot detect light
What causes the blind spot
At the point in the retina where the optic nerve leaves the eye there is no room for rods or cones, if light falls on this part there are no light sensitive cells to detect it
What is the optic chiasma
The cross shape where some of the info from the left and right eye cross over to pass into the opposite side of the Brain
What is the visual cortex
The area at the back of the brain that interprets visual information
How does the brain work
Visual info is carried from the optic chiasma to the back of the brain , the visual cortex then interprets the info from rods and cones, uses info from perception to understand shape and distances-also fills in gap left from the blind spot
What are depth cues
Visual clues that we use to understand depth or distance
What are Monocular depth cues
Clues to distance that only need 1 eye.
What are the 5 monocular depth cues
- superimposition
- relative size
- texture gradient
- linear perspective
- height in plane
What are binocular depth cues
Clues to distance that need both eyes
What is size Constancy
Perceiving an object as the same size even when it’s distance from us changes
How does size constancy work
When an object is close=brain scales it down
When an object is far=brain scales it up
What is stereopsis
A binocular depth cue to depth
The greater the difference between the view seen by the left and the right eye, the closer you’re looking
How does stereopsis help us see depth
The brain compares info from left and right eye after the optic chiasma.
When looking at something far=2 images are very similar
When eyes are focused nearer=views from each eye are different
Brain judges how different they are
What are the gestalt laws
- figure and ground
- similarity
- proximity
- continuity
- closure
What is figure and ground
A small complex symmetrical object (figure) is seen to be seperate from a background (ground)
What is similarity
Figures sharing size shape or colour are grouped together with other things that look the same
What is proximity
Objects which are close together are perceived to be related
What is continuity
Straight lines, curves and shapes are perceived to carry on being the same
What is closure
Lines or shapes are perceived as complete figures even if parts are missing
What are illusions
A conflict between reality and what we perceive
What are the illusions
- fictions
- after effects
- ambiguous figures
- distortions
What is a fiction
An illusion caused when a figure is perceived to be there even though it’s not present in the stimulus
What is illusory contour
A boundary/edge that is perceived in a figure but is not present in the stimulus
What is a motion after effect
An illusion caused by paying attention to movement in one direction and perceiving movement in the opposite direction immediately after
What is a colour after effect
An illusion cause by focusing on a coloured stimulus and perceiving opposite couloirs immediately after
An example of a motion after effect
Credits at the end of a film watching them moving upwards, if you look to the side of the screen they will appear to be moving downwards
What are the colour after effect pairs
Red and green
Yellow and blue
What is an ambiguous figure
A stimulus with two possible interpretations in which it is possible to perceive only one of the alternatives at any time
Example of an ambiguous figure
The necker cube
Leepers lady
What are distortions
Where our perception is deceived by some aspects of the stimulus. this can affect the shape or size of an object
Examples of distortions
ponzo illusion
Muller-lyer illusion
Hering illusion
Ebbinghaus illusion
What is a schema
A framework of knowledge about an object, event of group people that can affect our perception and help us organise information and recall what we have seen
What is perceptual set
The tendency to notice some things more than others. This can be caused by experience, context or expectations
