Chapter 3: Perception

Question 1

Define perception

Answer 1

Multiple definitions:
(1) experiences resulting from simulation of the senses.
(2) the act of becoming aware of something through our senses
(3) pattern recognition: ability to detect meaningful patterns in the environment (faces, objects, etc.)

Question 2

Describe what inverse projection problem is and the factors contributing to the inverse projection problem.

Answer 2

-Inverse projection problem is the idea that a particular image on the retina could have been caused by an infinite number of different objects and it is the task of determining which object is responsible for a particular image on the retina
-Factors contributing to inverse projection problem = objects can be hidden/blurred, view invariance

Question 3

What is viewpoint invariance/view invariance?

Answer 3

people’s ability to recognize an object even when it’s seen from different viewpoints (this is a factor the contributes to the inverse projection problem)

Question 4

Perception is built on a foundation of _______ from the ________?

Answer 4

information, environment

Question 5

Describe what bottom-up processing is and how it works.

Answer 5

The sequence of events from the from the eye to the brain is called bottom-up processing

How it works:
(1) A person looking at a desk creates an imaging on the retina.
(2) The image generates electrical signals.
(3) The electrical signals are transmitted through the retina, and then to the visual receiving area of the brain.

Question 6

What is top-down processing?

Answer 6

The knowledge we have of the environment is the basis of top-down processing. Top-down processing is…
- Processing that originates in the brain, at the “top” of the perceptual system
- Knowledge that allows people to rapidly identify objects and scenes and go beyond identification of objects and determining the story behind the scenes

Question 7

Give two perceptual examples of top-down processing

Answer 7

Answer =
(1) Perceiving objects
- Example = Multiple personalities of a blob
- All the blobs are identical but are perceived as different objects depending on their orientation and context that they are in because of our knowledge of the kinds of objects that’re likely to be found in different types of scenes.
(2) Hearing words (in a sentence)
- A person listening that only knows English and another person that only knows Spanish can receive identical sound stimuli but experience different perceptions which means that each of these person’s experience with language is influencing their perception.

Question 8

What is speech segmentation?

Answer 8

ability to tell when one word in a conversation ends and the next one begins. (Need to know the meaning of words to tell when one word in a conversation ends and the next starts)

Question 9

What are transitional properties? Give an example.

Answer 9

Answer = the likelihood that one sound will follow another within a word.
Example, the words “pretty baby.” It is likely that “pre” and “ty” will be in the same word (pre-tty) but less likely that “ty” and “ba” will be in the same word (pretty-baby)

Question 10

What is statistical learning?

Answer 10

Process of learning about transitional properties (the likelihood that one sound will follow another within a word) and about other characteristics of language

Question 11

An experiment by Saffran demonstrated that infants can learn transitional probabilities. In this experiment, infants were presented with nonsense words such as “bidaku” and “padoti”. This experiment showed transitional properties of within words and between words. Which one (within or between) had higher transitional properties?

Answer 11

Within word, 100%

Transitional properties within word was 100% and between words was 33% which concluded that the ability to use transitional properties to segment sounds into words begins at an early age

Question 12

What two types of information does perception depend on?

Answer 12

bottom-up (information stimulating the receptors) & top-down (information based on knowledge)

Question 13

Describe Helmholtz’s Theory of Unconscious Inference, is it top-down or bottom up?

Answer 13

Top-down b/c this is a process in which the perceptual system applies the observer’s knowledge of the environment in order to infer what the object might be

Description = Helmholtz realized that the image on the retina is ambiguous (a particular pattern of stimulation on the retina can be caused by a large number of objects in the environment). Lead to theory of unconscious inference which states:
–> our perceptions are the result of unconscious assumptions or inferences that we make about the environment (basically, perceptions are concluded based off of unconscious assumptions)
(ex: when staring at a picture with two rectangles, we infer that it’s likely that the rectangle is covering another rectangle b/c of experiences we’ve had with similar situations in the past)

Question 14

What is the likelihood principle?

Answer 14

States that we perceive the object that is most likely to have caused the pattern of stimuli we have received. (Preferred perceptual organization of a sensory pattern reflects the most likely object or event).

Question 15

What are Gestalt principles of organization? Is this top-down or bottom-up?

Answer 15

Bottom up

Gestalt principles of organization
Principle of good continuation
Principle of good figure/simplicity/Pragnanz
Principle of similarity
Principle of Closure
Principle of Common Fate
Principle of Proximity
Principle of Symmetry

Principle of good continuation = when connected, result in straight or smoothly curving lines are seen as belonging together, and the lines tend to be seen in such a way as to follow the smoothest path.
Also, objects that are overlapped by other objects are perceived as continuing behind the overlapping object. (Like a rope, you know it’s all connected, and you don’t perceive the rope as separate strands, you know the rope all connects and is one long rope).

Principle of good figure/simplicity = Every stimulus pattern is seen in such a way that the resulting structure is as simple as possible
Example of this: the Olympic logo of five circles

Principle of similarity = Similar things look/appear to be grouped together

Principle of Closure = when you see an image that has missing parts, your brain will fill in the blanks and make a complete image so you can still recognize the pattern

Principle of Common Fate = Gestalt law of common fate states that humans perceive visual elements that move in the same speed and/or direction as parts of a single stimulus. A common example of this is a flock of birds. When several birds fly in the same direction, we normally assume that they belong to a single group.

Principle of Proximity = Elements that are close together will be perceived as a coherent group

Principle of Symmetry = Images that are perceived as symmetrical are experienced as belonging together

Question 16

What is Bayesian Inference? Is it top-down or bottom up?

Answer 16

Top down

Estimate of probability of an outcome is determined by two factors
(1) the prior probability /prior (our initial belief about the probability of the outcome)
(2) likelihood of the outcome

Bayesian inference = (Prior) x (likelihood) = probability of the outcome (provides specific procedure for what might be “out there”

Question 17

What are regularities in the environment? What are examples of this?

Answer 17

frequently occurring characteristics

Example:
Physical & Semantic
- Physical = shapes or orientations (Vertical/horizontal)
- Semantic = scenes

Question 18

What did Gestalt psychologists realize about perception? What did they say it was and what did they say it was not?

Answer 18

Gestalt psychologists realized that perception is based on more than just the pattern of light and dark on the retina; perception is determined by specific organizing principles.

Question 19

Explain according to Gestalt psychologists the role of experience in perception

Answer 19

experience plays a minor role. Although experience CAN influence perception, the role of experience is minor compared to the perceptual principles that are “built” into the brain systems.

Question 20

Compare and contrast Gestalt psychologists and Helmholtz’s theory/theories for how we perceive

Answer 20

theories differ in how much experience plays a role in perception.

Gestalt = experience is minor in perception & built-in system in the brain play a larger role in perception (experience minor role in perception)

Helmholtz = our knowledge of the environment enables us to determine what’s most likely to have created the pattern on the retina (experience major role in perception)

Question 21

Which of the following is NOT an example of regularities in the environment?
A. Blue associated with open sky
B. Green associated with landscapes
C. Verticals & horizontals associated with budlings
D. A boat associated with the ocean/sea
E. A cow associated with Christmas holiday

Answer 21

Answer = E, cows are not frequently associated with Christmas, a reindeer or Santa would make more sense.

Question 22

What are the two types of regularities in the environment? What role do they play in perception? Give examples of each.

Answer 22

Roles they play in perception = use them to help perceive scenes and objects within scenes

(1) Physical regularities
-Regularly occurring PHYSICAL properties of the environment
-Vertical/horizontal lines are more common in the environment than angled orientations

(2) Semantic regularities
-Characteristics associated with the functions carried out in different types of scenes
-Basically, “what is going on/happening in this scene?” – interpretation of a scene
(Example: Ask people to picture a microscope. People will not just picture a microscope but will also picture other details like perhaps someone with a lab coat looking into a microscope or looking into a microscope and looking at a microscopic slide that has bacteria on it, etc.)

Question 23

What is the oblique effect?

Answer 23

because there are more vertical/horizontal orientations compared to angled (oblique) orientations, we are able to perceive vertical/horizontal orientations easier than any other types of orientations (like oblique)
(Ex: turning)

Question 24

What is the light-from-above assumption

Answer 24

-We usually assume that light is coming from above because light in our environment (including the sun & ceiling lights) usually comes from above
-Light coming from above & left = indicated indentation leaving shadow
-light coming from another angle = look like bump instead of indentation
-Our perception of shapes is influenced by how they are shaded, combined with the assumption that the light in coming from above.

Question 25

What is scene schema?

Answer 25

The knowledge of what a scene contains

Question 26

How can we reduce the ambiguous options when perceiving an object?

Answer 26

Adding a person’s prior beliefs (from Bayesian approach) reduces possible shapes that could be causing that image.

Question 27

Which approach is different from the other four approaches of perception?

Answer 27

Gestalt approach (principles of organization are built in

Question 28

Compare the four approached to perception.

Answer 28

Different: Gestalt approach (principles of organization are built in). Previous experience LITTLE impact on perception, more focused on brain systems/mechanism, built-in principles can override experience.

The other three approaches have in common that we use data about the environment, gathered through past experiences in perceiving, to determine what is out there:

Regularities = physical & semantic occur regularly in the environment and we use this information during perception (pervious experience)

Helmholtz = perception is based on previous experience

Bayesian = previous experience in prior & likelihood = influence perception

Question 29

What is experience-dependent plasticity and what does the research on this conclude?

Answer 29

-Experience-dependent plasticity is the shaping of neural responding by experience, provides evidence that experience can shape the nervous system
-Research on experience-dependent plasticity shows that the brain’s functioning can be “tuned” to operate best within a specific environment

basically means that structure of the brain is changed by experience! Like how kittens that were only exposed to horizontals can still grow up to recognize horizontals thru experience

Question 30

What is the purpose of perception?

Answer 30

to create out awareness of what is happening in the environment, as when we see objects in scenes, or when we perceive words in a conversation.

Question 31

Perception and action involve which two pathways?

Answer 31

(1) Ventral (also known as what & perception pathway)
(2) Dorsal (also known as where, action, & how pathway)

Question 32

What are mirror neurons?

Answer 32

neurons that respond equally when we perform an action and when we witness someone else perform the same action

(Ex: then neurons when a monkey grabs an object & when monkey watches someone else grab the same object)

Question 33

Ungerleider & Mishkin (1982) studied how removing part of monkey’s brain affected its ability to identify an object and to determine the objects location. In the condition where the parietal lobes removed, what pathway was discovered?

Answer 33

When parietal lobes removed = monkey had difficulty solving the problem, this means that the pathway that leads to the parietal lobe is responsible for determining an objects location, so, the pathway leading from the striate cortex to the parietal lobe was called the where pathway/dorsal pathway

Question 34

Ungerleider & Mishkin (1982) studied how removing part of monkey’s brain affected its ability to identify an object and to determine the objects location. In the condition where the temporal lobes removed, what pathway was discovered?

Answer 34

task became difficult when part of temporal lobe was removed (lesioned/albated) this means that the neural pathway that reaches the temporal lobes is responsible for determining an objects identity. (pathway leading from striate cortex to temporal lobe called what pathway/ventral pathway)

Question 35

What is the Titchener illusion?

Answer 35

It’s a size-contrast illusion (size-contrast illusion means central target surrounded by larger context figures looks smaller than when central target is surrounded by smaller context figures).

Titchener illusion has two identical discs can be perceived as being different in size when one is surrounded by bunch of other smaller circles and the other is surrounded by bunch of other larger circles.

Question 36

What’s size constancy?

Answer 36

the ability to perceive an object as being the same size despite the fact that the size of its retinal image changes depending on its distance from the observer. (Normally, when an object is far away, its retinal image size becomes small, and when the object is near, its retinal image size becomes big (common sense, think of looking at something far (can’t see it well) and walking up to it (can see it clearer)).

Question 37

What is the Inferotemporal Cortex (IT) & how does it relate to perception?

Answer 37

What is it/How it relates?
(1) a region of the brain that is particularly involved in the visual processing and visual object recognition (also known as view invariant which is just people’s ability to recognize an object even when it’s seen from different viewpoints)
(2) contains areas that are selective for categories such as faces (FFA), bodies, and scenes

Location = on the lower portion of cortex of the temporal lobe (front end of ventral stream)

Question 38

How do people recognize 3D objects?

Answer 38

Recognition by compartments theory
Distinctive features theory
Template Matching Theory
Prototype theory

Question 39

Describe the object identification/recognition theories.

Answer 39

(1) Recognition by compartments theory (explains object recognition) (structural descriptions of objects)
-Describes the pattern recognition process in terms of how people recognize 3D objects! (They recognize 3D objects by identifying the building blocks that make up the objects)
–> we are able to recognize objects by separating them into geons (the object’s main component parts/an alphabet of 36 primitive shapes)
–> geons = fewer than 36 geons which are combined to create the objects we see in day-to-day life. For example, when looking at a mug we break it down into two components – “cylinder” and “handle”

(2) Distinctive features theory
- All complex perceptual stimuli are composed of distinctive and separable attributes called features
–> Feature = feature is any characteristic used to classify a phoneme or word (phoneme = smallest unit of speech distinguishing one word (or word element) from another)
-Allow observers to distinguish one object/person from another
-Pattern recognition is accomplished by mentally assessing the presence or absence of a checklist of critical features

(3) Template Matching Theory
-It’s the idea that pattern recognition happens by comparing an incoming sensory stimulation pattern to mental images or representations of patterns (templates) already in our head until a match is found.
-These patterns are labeled with the name of the object (Ex: birthday cake)
-Inefficient and fails to account for our ability to recognize new objects

(4) Prototype theory
-Template is not a literal match with an object, but is an average or typical instance of the many different views of that object
-This average is called a prototype and the theory that uses them for pattern recognition is called prototype theory
-Pattern recognition occurs when the features of the object to be recognized overlap with the features of the prototype
-DOES NOT REQUIRE = (1) an exact match between the object and the prototype (2) the storage of patterns for every possible view of an object

Question 40

What is the Thatcher illusion?

Answer 40

upside down face

phenomenon where it becomes more difficult to detect local feature changes in an upside-down face, despite identical changes being obvious in an upright face.

The thatcher illusion is a rotated face (upside-down) and when the face is rotated, we switch to noticing the individual facial features (the component information) b/c we don’t have a prototype of upside-down faces because we don’t know enough practice seeing upside down faces – we mostly only see right-side up faces!

Question 41

Where is the FFA area located? (be specific!)

Answer 41

FFA (fusiform face area) is located inside the fusiform gyrus which is located inside the inferotemporal cortex.

Question 42

Compare and contrast feedforward and feedback processes and the brain area’s involved.

Answer 42

(1) Feedforward = is when signal or information gets passed forward from one area to the next
o Bottom-up processing involves mostly feed-forward processes as information gets passed on from V1 forward
o V1  V2  V3 …  IT
(2) Feedback = When signal or information gets passed backward from a higher level (further from V1) area to the a lower level one
o Feedback processes are important for top-down influences on face and object recognition
o PFC  … IT  V2  V1

• V1 or primary visual cortex = which is where information from the eyes reach the cortex and the beginning of both dorsal and ventral visual streams
• Prefrontal cortex or PFC is important for taking context into account in top-down influences on face and object processing
• IT or inferotemporal cortex which is important for recognition of whole objects
• Fusiform Face Area (FFA): A region of the fusiform gyrus in
  IT that is an important part of the face network

Question 43

Aglioti experiment concluded that when asked subjects when just looking at the Titchener illusion, they _____________ (overestimated/underestimated the size) but when asked to use hand to grip or measure the size they didn’t ______________ (overestimate/underestimate) the size or think it was any different.

Answer 43

Overestimated, overestimate

Aglioti experiment concluded that when asked subjects when just looking at the Titchener illusion, they said the size was larger (in reality it was the same size) but when asked to use hand to grip or measure the size they didn’t overestimate the size or think it was any different.

Question 44

Damage to the visual pathway can result in …

A. Apperceptive Agnosia
B. Optic Ataxia
C. Prosopagnosia
D. Associative Agnosia

Answer 44

B, optic ataxia

Question 45

What is optic ataxia? Which pathway is damaged?

Answer 45

Optic ataxia is a problem with “visually-guided” behavior stemming from impaired representations in the dorsal (“where/how”) pathway.
(in-class video of old lady not being able to grab something in the air)
 There is damage to the dorsal pathway

Question 46

What is Apperceptive Agnosia? Which pathway is damaged?

Answer 46

inability to recognize objects despite intact perception of basic visual characteristics/failure of perception in which some basic visual functions (acuity, colour, motion) are preserved, while others, (shape, angle, size) may be disrupted
There is damage to the ventral (“what”) pathway

Question 47

What is associative agnosia?

Answer 47

refers to difficulty with understanding the meaning of what they are seeing. They can draw or copy but do not know what they have drawn. They correctly perceive the form and know the object when tested with verbal or tactile information but cannot identify the object.

Question 48

What’s Gist perception?

Answer 48

The ability for a person to recognize the meaning of a scene, or the “gist,” automatically during their first eye fixation on that scene; for example, they can recognize that it is a beach, a dining room, or a street.
-Takes about ~150 milliseconds
-Happens before conscious attention can be effectively deployed to explore the scene, hence it’s automatic
-Based on little information & influenced by colour, orientation, crowding/openness
-Doesn’t necessarily involve object representations or details

Question 49

What is Scene Layout Perception?

Answer 49

visual perception of an environment as viewed by an observer at any given time. It includes not only the perception of individual objects, but also such things as their relative locations, and expectations about what other kinds of objects might be encountered
-Similar to gist perception, but takes a few seconds more
-After a few seconds, we can perceive the spatial layout of objects in a scene
-Repeated layouts are learned implicitly (without awareness)

Question 50

What is Ensemble Perception/Statistical estimation?

Answer 50

Ensemble perception refers to the visual system’s ability to extract statistical information from groups of similar objects—often in a brief glance
-When there are many objects, the perceptual system can quickly extract “ensemble” properties (such as mean size, orientation, velocity, direction & more)
-Takes less than 50 milliseconds
-Possibly related mechanism: we can rapidly estimate the percentage of the group that is a certain colour or orientation

Question 51

What is Pattern Detection in perception?

Answer 51

Perceptual system can detect trends or outliers on a graph
-Related to ensemble perception & gestalt grouping by proximity

Question 52

You see a stranger on the street, notice sweat on their brow, they are wearing athletic clothing, and holding a water bottle. You start to think they are heading home after a workout. This would be an example of ________________.
(A) Bottom-up processing
(B) Top-down processing

Answer 52

A, bottom-up? No inference needed… or B?

Question 53

You are on a farm and out of the corner of your eye you see something rush by. You couldn’t get a good look but, based on the fact that you are on a farm, you think you saw a sheep. This would be an example of ________________.
(A) Bottom-up processing
(B) Top-down processing

Answer 53

B, top-down? using previous information to infer it was a sheep

Question 54

Somebody throws something at your head. Which visual pathway is more likely to help you move out of the way of this incoming stimulus?
(A) Dorsal stream
(B) Ventral stream

Answer 54

A, dorsal stream

Question 55

most bottom-up processes are thought of feedforward , True or False?

Answer 55

True

Question 56

One of several areas of the brain that play a key role
in face recognition is a region of the ______________

Answer 56

fusiform gyrus
called the fusiform face area (FFA)

(FFA is inside fusiform gyrus is inside
inferotemporal cortex)

Question 57

What is a feedforward process?

Answer 57

When signal or information gets passed forward from one area to the next
(Bottom up processing involves mostly feed-forward processes as information gets passed on from V1 forward)

Question 58

What is a feedback process?

Answer 58

When signal or information gets passed backward from a higher level (further from V1) area to the a lower level one
-Feedback processes are important for top-down influences on face and object recognition

Question 59

__ or ________________, which is where
information from the
eyes reach the cortex
and the beginning of
both dorsal and
ventral visual streams

Answer 59

V1 or primary visual
cortex

Question 60

____ or _______________ is important for taking
context into account in top-down influences on
face and object processing

Answer 60

Prefrontal cortex or PFC

Question 61

T/F: IT or inferotemporal cortex is a region of the fusiform gyrus in IT that is an important part of the face network

Answer 61

FALSE! Fusiform Face Area (FFA): A region of the fusiform gyrus in
IT that is an important part of the face network.
IT or inferotemporal cortex which is important for
recognition of whole objects

Question 62

________________ is important for
recognition of whole objects

Answer 62

IT or inferotemporal cortex

Question 63

The ability to tell when one word ends and
another begins is/are ….

Answer 63

Speech segmentation

Question 64

Knowing which sound will likely follow another in a word is/are

Answer 64

Transitional probabilities

Question 65

What were the Transitional probabilities within word and between in Saffran’s experiment?

Answer 65

Transitional probabilities within word: 100%
Transitional probabilities btw words: 33%

Question 66

A problem with “visually-guided”behavior stemming from impaired representations in the dorsal (“where/how”) pathway is called _________________

Answer 66

Optic Ataxia

Question 67

difficult with mail slot task was due to ….

Answer 67

Apperceptive Agnosia

Question 68

Damage to the ventral (“what”) pathway can result in ….

Answer 68

Apperceptive Agnosia

Question 69

Compare and contrast Apperceptive Agnosia & Associative Agnosia

Answer 69

Apperceptive agnosic people can have difficulty
recognizing objects, but it is due to deficits perceiving
simple visual information (angle/width)
*Associative Agnosia: inability to recognize objects
despite intact perception of basic visual characteristics
*Usually caused by damage to the ventral stream

Question 70

In Prototype theory, prototypes are ______
a) based on the most salient or important example of an object
b) based on an average of many instances of an object
c) based on a highly detailed example of an object
d) based on the most recently viewed version of an object

Answer 70

B?

Question 71

Which of the following is not an example of bottom-up perception?
a) segmenting an auditory stream into separate words
b) extracting the basic meaning or gist of a scene
c) perceiving the average facial expression of a crowd
d) reaching for an object with the correct distance between fingers (grasping distance)

Question 72

If a word is identified more easily when it is in a sentence than when it is presented alone, this
would be an example of _____ processing.
a) bottom-up
b) top-down
c) serial
d) sequential

Question 73

Speech segmentation is ______
a) creating a sentence from a string of spoken words
b) ignoring the spaces between the spoken words of a sentence
c) recognizing a few words out of many when hearing a new language
d) organizing the sounds of speech into individual words

Answer 73

C?

Question 74

At a soccer game you can easily perceive the players as belonging to the same team because
they are all wearing the same colour of jerseys. This is an example of the law of _______
a) simplicity
b) similarity
c) pragnanz
d) familiarity

Answer 74

B?

Question 75

Which of the following statements is correct?
a) peripheral vision is used for integrating features off to the side
b) the centre of vision is subject to the blind spot on the retina
c) peripheral vision is outside the scope of attention
d) objects in the centre of vision fall within the fovea

Question 76

. After suffering a stroke, patients sometimes have difficulty reaching and grasping objects that
they can clearly see. This behaviour indicates likely damage to the ______ lobe.
a) temporal
b) frontal
c) parietal
d) occipital

Question 77

Mark is grocery shopping at the fruit stand. He reaches out to grab a nice looking peach that he
sees. Which brain network is most actively involved in guiding Mark’s movement based on the
peach he perceives?
a) ventral perceptual stream
b) dorsal perceptual stream
c) ventral attention network
d) dorsal attention network

Question 78

The ability for perceptual systems to rapidly (within 50 milliseconds) extract the average
orientation of a group of lines is called ______
a) pattern detection
b) statistical estimation/ensemble perception
c) gist perception
d) perceptual organization

Question 79

pathway from the visual cortex to the parietal lobe

Answer 79

action pathway

Question 80

pathway from the visual cortex to the temporal lobe

Answer 80

perception pathway

Question 81

research involving ablation in monkeys and patients with brain damage suggested two pathways. What are the two pathways and describe the root they take.

Answer 81

(1) from occipital lobe to temporal lobe responsible for perceiving objects (perception pathway)
(2) from occipital lobe to parietal lobe responsible for controlling actions towards objects (action pathway)

Question 82

What are geons?

Answer 82

identifying blocks

Question 83

What is the law of pragnanz? (also called law of good figure/principle of simplicity)

Answer 83

when people are presented with complex shapes or a set of ambiguous elements, their brains choose to interpret them in the easiest manner possible. (olympic rings = example)