TuT 6 Completly done Flashcards
Perception depth is based on cues name all the cues ?
- Monocular cues
- Binocular cues
Name the definition and parts of oculomotor cues:
The ability to make sense of the position of our eye and the ability to realize tansion in our eye muscles !
Convergence:
– Inward movement of eyes that occurs when we look at nearby objects.
Accommodation:
- Change in shape of lens that occurs when we focus on objects at various distances (far or close)
- Can either be Monocular or binocular
Definition of Monocular cues and main parts of monocular cues:
- Work with one eye (mono)
- Main part of mono cues:
1. Accommodation,Changes the shape of the lens to focus at variance distances
And uses:
- Pictorial motion ( Are fixed 2 dimensional cues for depth perception )
- Motion produced cues
Name the Monocular cues (pictorial motion cues)
- Occlusion
- Relative size
- Familiar size
- Texture gradient
- Realtive Height
- Perspective convergence
- Atmospheric perspective
- Shadows
Define occlusion:
- Partially hidden object seen as being farther away.
Define Relative size:
- When two objects are of equal size, the one farther away will take up less of our field of view than the one closer.
- based on knowledge
Define Fmiliar size:
- you can tell how big something is based on prior knowledge of size of objects.
Define texture gradient:
- Elements taht are father away are more seen as packed/ full.
- Ex: Flowers which u see up front can still be told apart and in the back not.
Define relative height:
- Objects with their bases closer to horizon are usually seen as being more distant.
Define perspective convergence:
- When parellle lines come closer together they seem to be more farther away
Define atmospheric perspective:
- Distant object are seen to be less sharp and have a slight blur tone
Define shadows:
Shadows can provide useful information about objects locations
Name the motion produced cues and the definition:
still monocular cues
Cues that emerge when we start moving, that support our perception of depth
- Motion Parallax
- Delection an accretion
Define motion parallax:
- Nearby objects appear to move rapidly where as far away objects move slowly
Example (If u look out the window while driving) - why because image of nearby objects travel larger distance
Define deletion and accretion:
As an observer moves sideways, some things become covered (= deletion), and others become uncovered (= accretion).
What is horopter ?
Imaginary circle in the eniviormnet which passes trough the objects.
- it contains all corresponding retinal points
- all of them have zero disparity
What is the absolute angle of disparity:
- Is the angle which provides information about the distance of objects
- It compares how far objects are away from horopter
- If far away then uncrosed disparity
- if close by then crossed disparity (repeat winkel)
- greater angel = greater distnce
- zero degree = corresponding points
- non zero degree = non corresponding points
- Absolut only figures out ditance between one object and horopter
What is relative disparity?
is the the difference between two object’s absolute disparities
- compare a horopter point with an object which lays before or behind horopter
What is stereopsis vision?
ability to use binocular disparity for depth information.
=Two slightly different images are are represneted to the person of the same object.
- USED BY 3D
What is the correspondence problem?
It trys to explain how the visual system matches images in both eyes. VIA:
- Uniqueness constraint
- Continuity constraint
- Do not need to know what these are but both explanations failed !!
What does the random dot stereogram show us ?
Conclusion: No monocular cues are needed to perceive depth perception only binocular disparity.
Where are binocular/disparity depth cells located:
- Primary receiving area = neurons for Absolute disparity
- Mostly Temporal lobe = neurons fo relative disparity
What is the goal of the experiment selective raring and microstimulation?
To proof that disparity/ binocular selective cells are responsible for stereopsis. (Depth perception)
Name the equation for size distance scaling:
And why is size distance constant?
S = K (R x D) R = Imagine on the retina D = Distance K = constant - When a person walks away retianl images get smaller (R) the distance gets larger (D)
What is the Emmert’s Law?
S = R x D
- Explain how the retinal size of an afterimage remains constant no matter where you are looking at.
- The farther away an afterimage image is the bigger it will be seen
Explanation for the illusion (Müller Lyer Illusion (Pfeil))
Misapplied size constancy scaling:
- Perceiving a 3D world meachnsim sometimes creates illusion when applied to 2D
conflicting cues theory
- Many cues build up to our perception which can stay in conflict with each other !
1. Actual length of vertical lines
2. overall length of figure
The Ponzo Illusion
Uses depth cues!
- The top object appears bigger because of the depth information provided by the convergence lines that make the object appear farther away (look at the picture)
Apparent distance theory
- The moon for example is seen as more close when it is up in the sky cause we can not provide dictance cues.
Angular size contrast theory
The moon appears smaller when surrounded by larger objects.
What does the HOLWAY AND BORING EXPERIMENT tell us ?
We can not perceive distant correct if not enough distant cues are provided !
