Module 4

Question 1

Exteroreceptive sensations

Answer 1

Any form of sensation that results from stimuli located outside the body detected by sensory organs

-vision, hearing, touch, pressure, heat, cold, pain, smell, taste

Question 2

Interoceptive sensations

Answer 2

Sensations from inside our body

-dancers for example have increased interoceptive accuracy

Question 3

Proprioception

Answer 3

Sense of where our limbs are in space

Question 4

Nocioception

Answer 4

Sense of pain due to body damage

Question 5

Equilibrioception

Answer 5

Sense of balance

Question 6

Synaesthesia

Answer 6

A neurological condition in which one sense automatically triggers the experience of another sense.

Ex. Grapheme-color synesthesia: a person sees colors with certain letters or numbers.

-One hypotheses is that it is due to cross wiring between processing areas in the brain
-artists are 8x more likely to have synesthesia than non-artists. Increases creativity

Question 7

McGurk effect

Answer 7

A voice articulating a consonant (ba) paired with a face articulating another one (fa) leads you to hear what you see

-illustrates dominance of visual input
-sounds doesnt change, its an illusion. What we’re seeing influences what we’re hearing

Question 8

What takes part in the early visual processing (sensation)?

Answer 8

Eyes and optic nerve

Question 9

Steps of early visual processing

Answer 9

1- light waves enter eye and are projected onto the retina
2- photoreceptors in the retina (rods & cones) convert light to electrical activity
3- the electrical signal is sent to bipolar cells and then to the ganglion cells
4- signal exits through the optic nerve to the brain

Question 10

Information compression

Answer 10

Because less ganglion cells than photoreceptors, you dont see everything that is out there in the world

Question 11

Rods vs cones

Answer 11

Rods: low light levels for night vision (very sensitive). Rods are mostly outside of the fovea, in the periphery. Thats why periphery of your visual field is less detailed and less accurate

Cones: high light levels for detailed color vision (not that sensitive). Cones are most concentrated in the fovea (central part of visual field). Thats why center of your visual field is most detailed

Question 12

Blindspot

Answer 12

No photoreceptors so visual stimuli are not received

Question 13

Why we’re not aware of blindspot

Answer 13

Because of perceptual filling-in. Later visual processes in the brain provide the missing informatiion.

+ left and right visual fields can compensate for each other’s blindspot

Question 14

Steps of late visual processing

Answer 14

1- thalamus
2-primary visual cortex (V1): edges, angles, color, light

And then the more high up we go in the visual stream, we find neurons that respond to features as specific as face, objects, or places.

3- visual association areas: interpretation

Question 15

What (ventral) pathway

Answer 15

From occipital lobe to temproal lobe

Question 16

Where (dorsal) pathway

Answer 16

Occipital to parietal lobe

Question 17

True or false: blindsight leads to deficits in imagining something but not in consciously processing incoming visual info

Answer 17

False. Blindsight leads to deficits in consciously processing incoming visual info but not imagery

Question 18

Akinetopsia

Answer 18

Visual motion blindness. Cannot see motion. Series of stationary objects

Question 19

Damage to the dorsal pathway

Answer 19

Optic ataxia. Inability to reach for objects.

Question 20

Damage to ventral pathway

Answer 20

Visual agnosia. Difficulties recognizing everyday objects

Question 21

Prosopagnosia

Answer 21

Fusiform face area damage leads to a selective deficit in recognizing faces. Can see other objects

Proof that selective face processing in the brain: sheep farmer with prosopagnosia. Couldnt recognize faces but was able to recognize and discriminate sheep with very high accuracy (90%)

Question 22

Apperceptive visual agnosia

Answer 22

Failure to recognize objects due to problems with perceiving the elements of the objects as a whole.

-they can detect different features but cant group them together as a whole = cant create a single perception in the brain
-memory is fine: can draw from memory. But cant copy!

Question 23

Associative visual agnosia

Answer 23

Inability to associate visual input with meaning.
-deficit is in being able to access information about the object
-can copy but cant draw object from memory.
-cant name or identify objects

Question 24

Constructivist theory of perception

Answer 24

-Top-down
-perception is influenced by stored knowledge and context

Question 25

What happens when the assumptions we make about the sensory input is wrong?

Answer 25

Illusions!

Question 26

Direct perception

Answer 26

A theoretical approach to perception that holds that the sensory stimuli be used to guide behavior in an action-perception loop

-rejects idea that brain constructs an intermediate mental model of the world ehich is then used to guide behavior. Instead, according to this view, perception is direct

Question 27

Density of a texture provides information about:

Answer 27

Distance. Near objects are farther apart and far objects are closer together

Question 28

Pattern recognition theory

Answer 28

Identifying a pattern in visual input (percept/probe) and matching that pattern to existing patterns stored in memory

The highest similarity between the probe and memory trace will determine recognition

Question 29

Template matching theory

Answer 29

Every object has a template in long-term memory
-too simplistic
-cannot explain: identification of two different and dissimilar views of the same object + classification of a novel image (such as a rare unseen bird) into the known category of birds

Question 30

Prototype theory

Answer 30

You have an average representation of an object in your brain. Recognition is determined by a good enough match (resemblance)
-allows for flexible object identification

Question 31

Feature detection

Answer 31

Visual input is broken down into individual parts (features). Each feature is processed separately. The combination of features is used as a pattern for recognition to compare to a prototype

-geons (features) have distincts propergies that we can perceive from any angle/view/perspective. Thus, explains how we can recognize objects with shifts in perspective

Question 32

Scene consistency effect

Answer 32

When object is consistent in a scene it is easier to recognize it. Ex cocotte dans une forêt vs cocotte dans une salle de bain. Et gars famous au bar (unexpected) vs gars famous sur le tapis rouge (consistent).

Question 33

What is a bi-stable image?

Answer 33

Has the possibility of being perceived in two different ways (two different perceptions)

Question 34

Dorsal and ventral stream: which is for action and which is for perception

Answer 34

Dorsal: action
Ventral: perception

Question 35

Figure-ground cues

Answer 35

-Convexity (figure is normally convex)
-Symmetry (figure is normally symmetrical, same on each side)
-Smaller region (smaller regions as figures, background is usually bigger)

Question 36

_ is a cue to depth based on the fact that our two eyes are in somewhat different positions on our head

Answer 36

Binocular disparity

Question 37

Structure-based model of recognition vs view-based model of recognition

Answer 37

Structure-based: brain extracts 3d features from objects and uses them to determine what the object will look like under different conditions.
-once you have encountered an object from one viewpoint you should be able to identify it from other view points. VIEWPOINT INVARIANCE

View-based model: 2d image of objects in order to identify them. We store multiple views of that object so when we encounter it again will be close enough to one of the stored examples.
-here you should be best at recognizing an object from a specific viewpoint and other viewpoinys should be more difficult. VIEWPOINT DEPENDENCY