Pattern Recognition

Question 1

what is the main problem with forming representations of objects?

Answer 1

shape constancy - objects can appear in many different orientations, therefore limiting theories of perception

Question 2

what are theories of bottom-up pattern recognition?

Answer 2

template theory
feature theory
RBC theory

Question 3

template theory

Answer 3

uses pattern activity to perceive objects

whatever memory representation most closely matches the object is what one thinks the object is

Question 4

problems with template theory

Answer 4

transformations
obstructed objects
doesn’t involve features

Question 5

feature theory

Answer 5

counts up matching feature between perceptual and memory representations

Question 6

what is evidence supporting feature theory?

Answer 6

the visual system uses features

caricatures are recognized better than realistic line drawings

Question 7

problem with feature theory

Answer 7

doesn’t account for the relationship between features

Question 8

RBC theory

Answer 8

uses features to deconstruct objects into geons

Question 9

geon

Answer 9

basic geometric shape

Question 10

RBC theory matching process

Answer 10

detect object
find view-invariant properties of the object
determine the component geons using view-invariant properties
match geons to memory

Question 11

what is evidence supporting RBC theory?

Answer 11

allows one to recognize partial or degraded objects
the more complex an object is, the easier it is to recognize it
harder to recognize objects in unusual orientations

Question 12

problems with RBC theory

Answer 12

little neuroscientific supporting evidence
doesn’t explain how one can distinguish similar objects from each other
doesn’t account for recognizing objects when not in their usual contexts

Question 13

bottom-up pattern recognition is driven by what?

Answer 13

stimulus data

Question 14

top-down pattern recognition is driven by what?

Answer 14

prior knowledge and past experiences

Question 15

types of top-down effects

Answer 15

expectation/bias
environmental context effects
word superiority effect

Question 16

expectation/bias effect

Answer 16

your own expectations/biases can affect one’s perception of something

Question 17

signal detection theory

Answer 17

neural activity increases when a signal is detected among noise

Question 18

signal

Answer 18

something in the environment one is trying to detect

Question 19

noise

Answer 19

things in the environment other than the signal

Question 20

sensitivity

Answer 20

how well one discriminates a signal from noise

Question 21

decision criterion

Answer 21

the level of activity required to determine that a signal is present
aka the threshold

Question 22

“yes” bias

Answer 22

more likely to say a signal is present than that it’s not present
caused by lowering the decision criterion

Question 23

“no” bias

Answer 23

more likely to say a signal isn’t present than that it is present
caused by raising the decision criterion

Question 24

what does response accuracy depend on?

Answer 24

bias
sensitivity
proportion of “yes” responses and “no” responses

Question 25

environmental context effects

Answer 25

when the perception of an object is affected by its context or environment

Question 26

examples of environmental context effects

Answer 26

subjective contours
ambiguous letters
objects out of context

Question 27

word superiority effect

Answer 27

it is easier to identify a letter when it’s presented in the context of a word than when it’s presented alone

Question 28

results of the forced-choice task

Answer 28

words are remembered better than non-words and single letters
pronounceable non-words are remembered better than unpronounceable non-words