Lecture 3: Perception

Question 1

Perception

Answer 1

The means by which information acquired from the environment via the sense organs is transformed into experiences of objects, events, sounds, tastes, etc.

Question 2

Distal stimulus

Answer 2

The thing you are trying to perceive

Question 2

Proximal stimulus

Answer 2

Pattern made by distal stimulus on sensory organ

Question 3

Percept

Answer 3

Mental representation of stimulus

Question 4

Lack of correspondence

Answer 4

Lack of correspondence: When the percept does not correspond to the distal stimulus, ex. optical illusion

Question 5

Paradoxical Correspondence

Answer 5

When proximal stimulus does not correspond to distal stimulus (but percept does), ex. a moving object, two object of same size at a different distance, etc.

Question 6

Direct Perception

Answer 6

The environment provides all necessary cues, our brains are pre-wired to pick up cues, and stimulus information is almost always unambiguous

Question 6

Perceptual Constancy

Answer 6

Our perception of an object’s features remain constant even when viewpoint (and proximal stimulus) changes
○ Perception of size does not change with distance
○ Perception of color does not change with light
○ Perception of shape does not change with angle

Question 7

Constructivist Theory

Answer 7

Perception uses data from the world and our prior knowledge and expectations; sensory information is often ambiguous and we must rely on our prior knowledge

Question 8

Bottom-Up Processing

Answer 8

Processing that is driven by the external stimulus rather than internal knowledge

Question 9

Top-Down Processing

Answer 9

Processing that is driven by knowledge and expectations

Question 10

Paradox of Depth Perception

Answer 10

Distal stimulus is 3D, projects a 2D proximal stimulus on the retina, but the percept is 3D. This is done by exploiting depth cues

Question 11

Linear Perspective

Answer 11

Lines converge into a hypothetical point, where they are more convergent the “distance” is further, and the more divergent they are the closer that part of the image is to the viewer

Question 12

Shape Cues

Answer 12

Shapes closest to you appear as they are, but distort when further, conveying distance. Ex. tiles close to you on the floor are more square, and those in the distance are more rectangular in your vision

Question 13

Interposition

Answer 13

One object blocking the view of another makes the blocking object appear closer

Question 14

Relative Size

Answer 14

An object closer to you will be bigger in your vision than one further away

Question 15

Shadow Cues

Answer 15

We assume lights come from above

Question 16

Retinal Disparity

Answer 16

The disparity in the retinal image on the two eyes are larger on things that are closer to the eyes compared to things further away. The brain uses how much the object moves to detect distance

Question 17

Accommodation

Answer 17

Lens changes to get a good focus on something closer vs. further away. Lens widens when an object is closer to you, and becomes flatter for objects further

Question 18

Convergence

Answer 18

The closer an object is to you the more your eyes cross, or converge

Question 19

Agnosia

Answer 19

Inability to identify objects or people

Question 19

Dorsal Pathway

Answer 19

Located in the occipital and parietal lobes, it processes location and movement; the “where” pathway

Question 20

Ventral Pathway

Answer 20

Located in the occipital and temporal loves, it processes color, shape, and identity; the “what” pathway

Question 21

Dr. P’s deficits and preserved abilities

Answer 21

○ Could not recognize people he knew
○ Could not identify objects
○ Could make out the abstract shapes that made up and object (i.e. 5 protrusions coming from a glove), then relate those to something he knew
○ Vision was not impaired
○ Memory was not impaired