LECTURE 5- PERCIEVINIG OBJECTS

Question 1

What is Gestalt Psychology

Answer 1

we detect objects initially by its features

describes how we separate and link objects into individual objects.

the key principles are

1. similarity- tend to group together objects that are like each other
2. proximity- closer objects are more likely we will group them
3. good continuation- organize objects where contours and lines continue smoothly
4. closure- bias towards perceiving closed objects over incomplete ones
5. simpicity- we interpret objects in the simplest way
6. figure ground segregation= separate objects from its background

Question 2

strengths and weaknesses of Gestalt psychology

Answer 2

strengths- simple/ focus on fundamental issues/ applicable to complex images

weakness= deemphasizes the importance of past experiences/ provides descriptions not explanations/ all these principles are based on 2d images

Question 3

Feature detection=

Answer 3

feature detection is the initial step- identifying objects thru pattern, fragment, or components. Objects appear in combination with other features across a variety of stimuli e.g. each letter A G H have a horizontal line

Question 4

feature nets=

Answer 4

bottom up- how we detect features; hierarchy. Starts with simple shapes then letters then words for example. Top down- e.g. thought about animals then think Cat then letter c.

Question 5

recognition by components theory=

Answer 5

all objects are reduced to geometric ions which can be combined to make a more complex object
suggests perceiving is the first major step

Question 6

evidence for RBC theory

Answer 6

(Biederman 1987)- if a pattern is degraded it matters where it is degraded. You have non recoverable objects which is where points where objects meet/ vertices are missing so we can no longer recognize the objects. Recoverable objects is where segments of smooth continuous edges are missing but vertices are there which is easy to fill in the gaps.

Question 7

weakness of RBC theory

Answer 7

it is tied to bottom up processing- some evidence contradicts the features first aspect model because whole objects can be perceived rapidly and automatically.

embodied cognition= perception of objects is influenced by our expectation of how we will interact with those objects but RBC dies not explain this

Question 8

what are some binocular cues

Answer 8

each eye has a different view of the world (stereopsis)

the difference is bincoluar disparity

Question 9

what are oculomotor cues

Answer 9

convergence= eye turn inwards when we focus on close objects

accommodation= shape of lenses in the eye changes depending on distance

Question 10

what are monocular cues

Answer 10

interposition= blocking of our view of one object by another

linear perspective= parallel lines seem to converge as they get further away from the view

texture gradients= as surface gets further away texture appears finer and smoother

Question 11

what are motion cues

Answer 11

motion parallax= nearby objects move more rapidly that far away objects

optic flow= images get larger as we approach them