Week 3 - Perception

Question 1

Perception (definition)

Answer 1

We define perception as experiences resulting from stimulation of the senses. To

Question 2

Perception (definition)

Answer 2

Experiences resulting from stimulation of the senses

Question 3

Inverse Projection Problem

Answer 3

The task of determining the object responsible for a particular image on the retina

Question 4

Viewpoint invariance

Answer 4

People’s ability to recognize an object even when it is seen from different viewpoints

Question 5

Two types of information used by the human perceptual system

Answer 5

(1) environmental energy stimulating the receptors and

(2) knowledge and expectations that the observer brings to the situation.

Question 6

Speech segmentation

Answer 6

The ability to tell when one word in a conversation ends and the next one begins

Question 7

Transitional probabilities

Answer 7

The likelihood that one sound will follow another within a word

For example, consider the words pretty baby. In English 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 8

Statistical Learning

Answer 8

The process of learning about transitional probabilities and about other characteristics of language

Question 9

Likelihood principle (perception)

Answer 9

We perceive the object that is most likely to have caused the pattern of stimuli we have received. This judgment of what is most likely occurs, according to Helmholtz, by a process called unconscious inference, in which our perceptions are the result of unconscious assumptions, or inferences, that we make about the environment.

Question 10

Two types of regularities in the environment.

Answer 10

Physical Regularities

Symantic Regularities

Question 11

Oblique Effect

Answer 11

people can perceive horizontals and verticals more easily than other orientations (due to physical regularities)

Question 12

light-from-above assumption

Answer 12

We usually assume that light is coming from above, because light in our environment, including the sun and most ar-tificial light, usually comes from above

Question 13

Semantic Regularity (in the case of scenes)

Answer 13

In language, semantics refers to the meanings of words or sentences. Applied to perceiving scenes, semantics refers to the meaning of a scene.

Question 14

Physical regularities

Answer 14

Physical regularities are regularly occurring physical properties of the environment.

Question 15

Bayesian inference - Thomas Bayes (1701–1761)

Answer 15

our estimate of the probability of an outcome is determined by two factors: (1) the prior probability, or simply the prior, which is our initial belief about the probability of an out-come, and (2) the extent to which the available evidence is consistent with the outcome. This second factor is called the likelihood of the outcome.

Question 16

unconscious inference - Who’s theory, and meaning.

Answer 16

Hermann von Helmholtz (1821–1894)
Unconscious inference - A judgement in which our perceptions are the result of unconscious assumptions, or inferences, that we make about the environment.

(…Thus, we infer that it is likely that Figure 3.14a is a rectangle covering another rectangle because of experiences we have had with similar situations in the past. )