PERCEPTION

Question 1

Perception:

Answer 1

interpretation of the sensory information to figure out what is out there and where it is.

Question 2

Perception is the result of the reciprocal interaction between …………………… processes.

Answer 2

bottom-up and top-down

Question 3

top-down:

Answer 3

expectation-driven processing

internal knowledge, beliefs, goals

Question 4

bottom-up:

Answer 4

stimulus-driven processing (information from the external environment)

Question 5

Same input can be interpreted in different ways

True or False?

Answer 5

True

Question 6

can you see both interpretations at once?

Answer 6

No, but can spontaneously alternate between the two interpretations.

Question 7

What does the bistable perception demonstrate?

Answer 7

The visual system is highly dynamic and continuously recalculates the best possible solution to the ambiguity in sensory info.

Question 8

Gestalt is German for???

Answer 8

“form” or “shape”

Question 9

What did Gestalt psychologists begin to uncover?

Answer 9

some of the grouping principles that guide the visual system and produce our perception of what goes with what.

Question 10

The Gestalt Laws:

Answer 10

provide a description of perceptual principles that aid in our perception of whole forms.

Question 11

Visual stimuli are perceived in a way that most simply…?

Answer 11

organises the different elements into a coherent form.

Question 12

Name the 6 Gestalt Laws

Answer 12

proximity, 
similarity, 
symmetry, 
continuity, 
closure, 
figure-ground

Question 13

Describe the Gestalt Law Proximity

Answer 13

(no grouping)

elements that are close are perceived as forming a group

Question 14

Describe the Gestalt Law Similarity

Answer 14

elements that are similar are perceived as forming a group

colour
size
orientation

Question 15

Describe the Gestalt Law Symmetry

Answer 15

elements that form a figure that is symmetric around its centre are perceived as a group

Question 16

Describe the Gestalt Law Continuity

Answer 16

continuation groups the dots into two lines that are intersecting

Question 17

Describe the Gestalt Law Closure

Answer 17

edges that are separated by gaps are perceived as belonging to complete objects

Question 18

Describe the Gestalt Law Figure-groud

Answer 18

some elements are prominent (figure) while other elements recede into the background (ground)

Question 19

Describe image-based models

Answer 19

Template matching models: Match the whole image to the stored representation

Question 20

Describe Part-based models

Answer 20

Recognition-by-components model: Specify the parts and spatial relations among the parts of 3D objects

Question 21

Exemplar variation:

Answer 21

There many different instances of each object category and yet these can be recognized. How many templates can possibly be stored?

Question 22

What is Assumption in the recognition by components model?

Answer 22

Any 3D object can be described by their parts and the relations among these parts.

Question 23

Recognition by components model:

Answer 23

Recognition by components (RBC) model provides a building model that accounts for both parts and their spatial connections

Question 24

How many shapes does the recognition by components model define?

Answer 24

The model defines 36 shapes (called geons) that can build up any object

Question 25

What does the recognition by components model detect?

Answer 25

The models detects the geons and spatial relations and attempts match them to a known object

Question 26

Depth perception:

Answer 26

Ability to perceive the external world in 3D and distances to external entities. Projections on the retina are ambiguous and they could be caused by an infinite number of external entities.

Question 27

What are the 3 depth cues?

Answer 27

Monocular cues -Information from one eye Binocular cues -Information from both eyes Motion based cues

Question 28

Components of Monocular depth cues

Answer 28

Interposition - nearby objects occlude faraway objects Linear perspective - Parallel lines converge in the distance Relative size - for two objects that are typically the same size, the larger object is nearby and the smaller object is faraway. Texture gradient - Fine detail ("grain") of nearby objects can be seen while fine detail of faraway objects cannot.

Question 29

Interposition:

Answer 29

nearby objects occlude faraway objects

Question 30

Components of binocular depth cues

Answer 30

Binocular disparity - the eyes send more disparate signals to the brain when objects are nearby vs faraway. Difference in left and right retinal images provide information about depth. The larger the disparity the closer the object Convergence - the eyes turn more inward when objects are nearby vs faraway. Eye muscles provide information about the depth.

Question 31

Motion parallax:

Answer 31

when moving, distant objects appear to move slower.