Chapter 3 - Perception

Question 1

Perception

Answer 1

• experiences resulting from the stimulation of the senses

Question 2

Inverse projection problem

Answer 2

• task of determining the object that caused a particular image on the retina
• starting with the retinal image and extending rays out from the eye
• happens naturally

Question 3

viewpoint invariance

Answer 3

• the ability to recognize an object seen from different viewpoints
• knowing it’s the same object even though your angle has changed

Question 4

2 types of systems

bottom-up processing

Answer 4

1) looking at something creates an image on the retina
2) image generates electrical signals that are transmitted through the retina and then to the visual receiving area of the brain

• starts at the bottom when environmental energy stimulates the receptors

Question 5

2 types of systems

top-down processing

Answer 5

• knowledge we have of the environment
• originates in the brain at the “top” of the perceptual system
• enables us to rapidly identify objects
• filling in the blanks because of what we expect to see (context cues)

Question 6

top-down

speech segmentation

Answer 6

• the ability to tell when one word in a conversation ends and the next one begins
• why we can’t make sense of other languages (words realistically blend together)

Question 7

transitional probabilities

Answer 7

• the likelihood that one sound will follow another within a word

Question 8

statistical learning

Answer 8

• the process of learning about transitional probabilities and about other characteristics of language

Question 9

Helmholtz

likelihood principle

Answer 9

• we perceive the object that is most likley to have caused the pattern of stimuli we have received

Question 10

unconscious inference

describes likelihood principle

Answer 10

• our perceptions are the result of unconscious assumptions that we make about the environment

Question 11

Gestalt princples

apparent movement

Answer 11

• although movement is perceived, nothing is actually moving

Question 12

What idea did the Gestalt psychologists reject?

Answer 12

• that perceptions are formed by “adding up” sensations

Question 13

Gestalt

What 2 conclusions did Wertheimer come to regarding apparent movement?

Answer 13

• cannot be explained by sensations because there is nothing between the flashing lights
  - the whole is different than the sum of it’s parts

Question 14

What do the principles of perceptual organization explain?

Answer 14

• the way elements are grouped together to create larger objects

Question 15

Gestalt principles

Good continuation

Answer 15

• points that, when connected, result in straight or smoothly curving lines are seen as belonging together
• objects that overlap are seen as continuing behind
• ex. shoelaces (2 separate strings that we see as a whole)

Question 16

Gestalt principles

Pragnaz (principle of good figure, simplicity)

Answer 16

• every stimulus pattern is seen in such a way that the resulting structure is as simple as possible

Question 17

Gestalt principles

Similarity

Answer 17

• similar things appear to be grouped together

Question 18

regularities in the environment

Answer 18

• characteristics of the environment that occur frequently (ex. blue = open sky)
• provide information we can use to resolve ambiguities

Question 19

Physical regularities

Answer 19

• regularly occuring physical properties (ex. buildings are vertical just like most things in nature (trees))

Question 20

physical regularities

oblique effect

Answer 20

• people perceive horizontals and verticals more easily than other orientations

Question 21

physical regularities

light-from-above assumption

Answer 21

• we usually assume that light is coming from above because that is how it normally is in our environment

Question 22

Semantic regularities

Answer 22

• “semantics” refers to the meanings of words or sentences
• when applied to perception, semantics refers to the meaning of a scene
• characteristics associated with the functions carried out in different types of scenes (context)
• ex. when asked to imagine an office, we know we are thinking of an office because of the things we imagine are in that room (chair, desk, paperwork, etc.)

Question 23

semantic regularities

scene schema

Answer 23

• our visualizations contain information based on our knowledge of different kinds of scenes
• expectations created by scene schemas contribute to our ability to perceive objects and scenes

Question 24

Bayesian inference

Answer 24

• the idea that our estimate of the probability of an outcome is determined by the prior probability and the likelihood

Question 25

Bayesian inference

prior probability (prior)

Answer 25

• our initial belief about the probability of an outcome

Question 26

bayesian inference

likelihood of an outcome

Answer 26

• the extent to which the available evidence is consistent with the outcome
• additional information added to our initial belief

Question 27

what are the 4 conceptions of object perception?

Answer 27

1) Helmholtz’s unconsious inference
2) the Gestalt principles
3) regularities in the environment
4) Bayesian inference

Question 28

How are the Gestalt principles different from the other 3 approaches?

Answer 28

• emphasizes the idea that the principles of organization are built in

the other 3 say we use data about the environment and past experiences to determine what is out there

Question 29

theory of natural selection?

why are there more neurons that respond to horizontals and verticals?

Answer 29

• characteristics that enhance an animal’s ability to survive, and therefore reproduce, will be passed on to future generation

Question 30

brain ablation

Answer 30

• removing part of the brain to determine its function

Question 31

object discrimination problem

Question 32

landmark discrimination problem

Question 33

‘what’ pathway (ventral)

Answer 33

• neural pathway, extending from the occipital lobe to the temporal lobe, that is associated with perceiving or recognizing objects
• corresponds to the perception pathway

Question 34

‘where’ pathway (dorsal)

Answer 34

• neural pathway, extending from the occipital lobe to the parietal lobe, that is associated with neural processing that occurs when people locate objects in space
• roughly corresponds to the action pathway

Question 35

perception pathway

Answer 35

• neural pathway, extending from the occipital lobe to the temporal lobe, that is associated with perceiving and recognizing objects
• corresponds to the what pathway

Question 36

action pathway

Answer 36

• neural pathway, extending from the occipital lobe to the parietal lobe, that is associated with neural processing that occurs when people take action
• corresponds to the where pathway

Question 37

mirror neurons

Answer 37

• neurons that respond both when a monkey observes someone else grasping an object such as food on a tray and when the monkey itself grasps the food

Question 38

mirror neuron system

Answer 38

• a network of neurons in the brain that have mirror neuron properties