Week 4 pt.2 : Object perception Flashcards
1
Q
An object is more than the sum of its parts…
A
- interpreting objects requires bottom-up & top-down cues
- example Oliver sacks book ‘the man who mistake his wife for a hat’
- patient w/ object agnosia
- thought leather glove was a change purse
- this patient had damage to inferotemporal lobe + it impaired his ability to bring together the bottom-up & top-down cues necessary to perform everyday tasks
2
Q
Ability to detect objects must overcome 3 aspects…
A
- Image clutter = to overcome, we must discern the object despite the overlapping presence of nearby objects
- object variety = we must recognize a specific object as part of a certain class/category despite small/large differences
- variable views = we must recognize an object despite is being in different orientations relative to our retinae (have to identify same object from different vantage points)
3
Q
Shape constancy…
A
- Object perception provides a great deal of flexibility & gives rise to shape constancy
- shape constancy is the idea that an object will be perceives to have the same shape, regardless of how its orientation changes on our retina
- it’s taken the world’s best software engineers decades to produce computer vision algorithms capable of distinguishing objects
4
Q
representation versus recognition
A
- representation = seeing someone as human
- recognition = their identity
5
Q
object recognition
A
- how an object and its parts are encoded by different areas of the brain
- the neural code for what the object acc is
- may include representations of object features (certain neurons) and object representations (conjunction of features)
6
Q
Object recognition
A
- association of the representation w/ those previously stored in memory to asses the identity, use/meaning of an object
- must recognize… specific objects objects as members of larger classes and objects as specific instances of that category
7
Q
Perceptual organization
A
- the process by which multiple objects in an environment are grouped, allowing us to identify objects in complex scenes
- 2 important processes… grouping & segregation
8
Q
grouping & segregation
A
- grouping = elements in a figure grouped together into a common unit/object
- segregation = distinguishing 2 objects as being distinct/discrete
9
Q
figure-ground organization
A
- we separate the figure from the ground
- we divide the world into 2 elements: figure/object of regard and ground/background
- example is the face-vase illusion
- from a bottom-up perspective, the physical features of an image can have an effect on how the figure-ground distinction is made (e.g. images near the bottom of a landscape are closer to us)
- this makes us decide objects in lower field = figure against the higher background
10
Q
stimulus component role in figure-ground relations
A
- stimulus components play a role too…
- we show a strong bias toward perceiving symmetrical objects as being figures interest
- also show bias toward objects with convex borders as being figures as opposed to concave borders
11
Q
Gestalt psychology
A
- Gestalt psychologists interested in understanding the rules by which perception picked out the whole from its parts
- they created the gestalt laws of perceptual grouping
- they’re a group of physical parameters present in stimuli that influence the likelihood/pattern by which they will be grouped into coherent visual objects
12
Q
Law of continuation
A
figures that have smooth edges are more likely to be seen as continuous than figures with edges with abrupt/sharp angles
13
Q
Law of proximity
A
elements close together usually perceived as a unified group
14
Q
Law of similarity
A
elements similar to one another perceives as a unified group
15
Q
law of symmetry
A
elements symmetrical to one another perceives as a unified group
