Chapter 3: Visual perception

Question 1

What is akinetopsia?

Answer 1

Unable to perceive motions( a for “without”, kine for “to move” and opsia for “seeing”)

Question 2

What is the route from the eye to the brain?

Answer 2

eye > optic nerve > LGN in thalamus > V1 in visual cortex

Question 3

What is/does the Lateral geniculate nucleus (LGN)

Answer 3

relay from optic nerve to V1

Question 4

What is the blind spot?

Answer 4

Without any rods or cones, optic nerve is there

Question 5

What is the blind spot?

Answer 5

Without any rods or cones, optic nerve is there

Question 6

What is lateral inhibition?

Answer 6

The way in which cells are stimulated inhibits neighbouring cells; enchanges edges

Question 7

What are Mach Bands?

Answer 7

Optical illusion illustrating edge enchantment, demonstrates that intrepretation and analysis begins in the eyeball

Question 8

Where does visual processing/analysis start?

Answer 8

In the eye (lateral inhibition)

Question 9

What is single-cell recording?

Answer 9

investigating moment-by-moment the pattern of electrical charges in a single neuron. Used to define receptive field

Question 10

What is single-cell recording?

Answer 10

investigating moment-by-moment the pattern of electrical charges in a single neuron. Used to define receptive field

Question 11

What is the receptive field?

Answer 11

The size and the shape of the area in the visual world to which a cell responds.

Question 12

What are center-surround cells?

Answer 12

In the visual system, center-surround cells fire more when they centre is stimulated.

Question 13

What are orientation-specific visual fields?

Answer 13

In the visual system, orientation-specific visual fields fire more when they detect a line in a specific orientation, less if that is not the case.

Question 14

What are edge-detectors?

Answer 14

In the visual system edge-detectors fire more when they detect notches or corners.

Question 15

What are motion detectors?

Answer 15

In the visual system movement detectors fire more when a stimulus moves from left to rights etc.

Question 16

What is parallel processing in the brain?

Answer 16

Different neurons in V1 are specialised, resulting in parallel processing which is quick because it is split up. Afterwards they are integrated.

Question 17

Where does the area V1 lies and what gives it its input?

Answer 17

Between the two hemispheres and in the occipital lobe. Gets it input from the thalamus.

Question 18

What are the two big upsides to parallel processing?

Answer 18

Speed and mutual influence among systems which is useful in some cases

Question 19

Is there a priority in systems in parallel processing?

Answer 19

No, systems negotiate a solution that satisfies both systems.

Question 20

What are P-cells: give it’s function, location and what they are specialised to do?

Answer 20

In the optic nerve P-cells provide main input for LGN parvocellular cells, which seem to be specialised for spatial analysis and detailed analysis of form.

Question 21

What are M-cells give it’s function, location and what they are specialised to do?

Answer 21

In the optic nerve M-cells provide main input for LGN magnocellular cells which are specialised for the detection of motion and the perception of depth.

Question 22

Define the what system; pathway and function

Answer 22

Some activation from occipital lobe passed to cortex of temporal lobe. Major role in object identification.

Question 23

Define the where system; pathway and function

Answer 23

Some activation from occipital lobe passed to cortex of parietal lobe. Major role in object in spacial recognition.

Question 24

What does a lesion in the what or where system mean?

Answer 24

They can for example not grab an object but can correctly identify it.

Question 25

What is the binding problem?

Answer 25

The question how parallel processed elements are combined. We see the world not as disjointed, it is combined somehow

Question 26

Give the three elements that contribute to the solution of the binding problem:

Answer 26

• Spatial position
• Rhythms/neural synchrony
• Synchronised neural firing

Question 27

What is spatial position (in the binding problem)?

Answer 27

Each brain part which does parallel processing keeps track of where the target/stimuli is, therefore the information can be resembled using the reference to the position.

Question 28

What is rhythms/neural synchrony (in the binding problem)?

Answer 28

if neurons for example a vertical line are firing in synchrony with movement detectors, these features are bound together.

Question 29

What is synchronised neural firing (in the binding problem)?

Answer 29

Synchronised firing occurs only when attending to a specific stimulus but does not occur in neutrons activated by unattended stimuli.

Question 30

What are conjunction error and when do they happen?

Answer 30

When a person’s attention is overloaded (for example coloured colour words), they can bound/conjoin features wrongly.

Question 31

Where does binding happens?

Answer 31

Visual system

Question 32

What is a Necker Cube

Answer 32

A ambiguous figure; you can see either A or B but not at the same time.

Question 33

What is figure/ground

Answer 33

We split the figure (foreground) from ground (what is in back)

Question 34

What is spatial arrangement?

Answer 34

neurons that are sensitive to information in a region are close to neurons that are sensitive to information in adjacent regions.

Question 35

Why do we only see one form?

Answer 35

Brain goes for the simplest interpretation of a object

Question 36

What are the Gestalt Principles?

Answer 36

your perception is guided by similarity, proximity, good continuation, closure and simplicity

Question 37

What causes a illusion (example table)

Answer 37

Shape constancy > Cues to depth, which are not suppressible, cause wrong interpretation.

Question 38

What is cue to depth?

Answer 38

Perceiving 2D figures as 3D figures adjusting for viewing angles

Question 39

What is perceptual, size, shape and brightness constancy?

Answer 39

We perceive constant properties of objects in the world even when sensory information changes

Question 40

What happens in unconscious inference?

Answer 40

In perceptual constancy, taking one aspect of the input (e.g., the distance to the target) into account in interpreting another aspect (e.g., the target’s size). This process is usually quite accurate, but it can produce illusions.

Question 41

What can cause a contrast effect in a illusion?

Answer 41

Lateral inhibition.

Question 42

What are distance cues?

Answer 42

features of a stimulus that indicate a object’s position.

Question 43

What the difference between two eye’s views in perception called?

Answer 43

Binocular disparity, help to see depth without distance cues.

Question 44

What are monocular cues?

Answer 44

depth cues that depend on what one eye sees, for example pictorial cues(depth on a flat surface) and interposition (something blocks view of object means it is closer)

Question 45

What is linear perspective?

Answer 45

A cue for distance based on the fact that parallel lines seem to converge as they get farther away from the viewer.

Question 46

How can you perceive depth trough motion?

Answer 46

motion parallax or optic flow

Question 47

Why is our visual system influenced by so many (distance) cues?

Answer 47

Because different distance cues become important in different circumstances

Question 48

How do we achieve constancy?

Answer 48

Trough unconscious inference we take one aspect of the input and take it into account interpreting other aspects