Ch3 - Visual Perception

Question 1

Layers of retina

label diagram 2 + cell names + purpose

Answer 1

Photoreceptors
Horizontal cells
Bipolar cells
Amacrine cells
Ganglion cells

combine information between cell layers

Question 2

Lateral inhibition

definition + purpose

Answer 2

when cells are stimulated, they inhibit the activity of neighboring cells

enhances the edges of an image (eg: letters, outline of an animal…)

Question 3

parallel processing advantages

vision

Answer 3

1. higher speed and efficiency
2. different parts of the brain work together as they are active simultaneously

Question 4

two pathways of visual processing from the occipital lobe

name + location + purpose + pathology

Answer 4

posterial parietal cortex: parietal lobe, where pathway (object location + movement)
- damage leads to difficulty reaching for objects

inferotemporal cortex: temporal lobe,what pathway (object identification)
- damage leads to visual agnosia

Question 5

One challenge the brain faces due to stimuli being processed in different brain regions

name

Answer 5

the binding problem
brain must reunite elements of a stimulus to create a cohesive perception

Question 6

Elements which help solve the binding problem

names + method

Answer 6

1. Spatial Position: maps out information from different pathways onto the same visual map (eg: ball is to the left AND red AND moving)
2. Neural Synchrony: neurons firing synchronously are attributed to the same object
3. Attention: helps link and group features, lack of attention can lead to conjunction errors

Question 7

gestalt principles

list + see image 1 for examples

Answer 7

• Similarity
• Proximity
• Continuation
• Closure
• Simplicity

Question 8

perceptual constancies

definitino and attributes

Answer 8

we percieve constant object properties despite changing viewing circumstances

• brightness
• size
• shape

eg: door has the same percieved shape and color, open or closed

Question 9

factors contributing to perceptual constancies

Answer 9

• distance cues (image size on the retina): eg. farther image occupies smaller space on the retina
• relationships with other objects: eg. comparing the height of a person to objects around them

Question 10

distance queues

main names of queues

Answer 10

• binocular disparity: difference between image as seen by each eye
• monocular distance queues: distance can be percieved by one eye
  
  • lens adjustment: how much the lens adjusts to get a clear image
  • pictorial cues: like interposition, (objects overlapping)
  • linear perspective: pattern of parallel lines indicate distance
• motion:
  
  • motion parallax: closer objects percieved as moving faster than far objects
  • optic flow: how our visual field changes as we move

Question 11

akinetopsia

symptoms

Answer 11

Motion blindness, cannot percieve motion accurately