Pattern Recognition Pt 1

Question 1

Pattern Recognition

Answer 1

• The study of how people identify the objects in their environment
• Engaging with a sensory experience and connecting it with our past experience/LTM
• Relies on top-down processing and bottom-up processing
• As long as the pattern is similar enough, we can identify what it is

Question 2

Theories of Pattern Recognition

Answer 2

1. Template Theories
2. Feature Theories
3. Structural Theories
   **Note that there isn’t a singular right theory!

Question 3

Captcha

Answer 3

• Even though we don’t have difficulty making out the words in captcha, it is not easy for a computer
• For captcha images, the different angles and variations in how objects look like make it difficult for a computer to correctly identify

Question 4

Template Theories

Answer 4

Template descriptions are when we measure the overlap between two patterns

Question 5

PHILLIPS (1974)

Answer 5

In a comparison between two patterns,

When the second pattern is in the same location as the first pattern, they can use their visual information store to compare.

But when the position of the second pattern is moved, it makes it more difficult to rely on the visual information store to compare.

Question 6

Problems with Templates

Answer 6

1. Perspective
2. Variability across templates
3. Doesn’t account for overlaps

Question 7

Problem: Perspective

Answer 7

According to the theory, templates need to be the same position and orientation.
Templates say that unless you know the image of the entire thing, you wouldn’t be able to identify things
Ex). 6 vs. 9

Question 8

Problem: Variability Across Templates

Answer 8

There can be a great deal of variability across templates, making them difficult to assess.
We don’t recognize categorization of patterns, of how certain examples are better representations than others.
Ex). The Triangle Types

Question 9

Problem: Doesn’t account for overlaps

Answer 9

Different and unique patterns can sometimes overlap one another.
Ex). O-C – The pattern for C also exists in the pattern for O

Question 10

Feature Theories

Answer 10

Focuses on the parts of the pattern being recognized.
Ex). green color, star shape, big size

Question 11

Hubel & Wiesel (1962, 1963)

Answer 11

• An electrode is inserted into the cranium of a cat and sees if the cell is picking up a signal. This is from the stimulus, which is a screen with lines.
• We want to know which neurons are sending messages to other cells through which ones light up when a line is shown

Question 12

Gibson on Letters (1969)

Answer 12

• States that the features should be critical ones, present in some members of the set but not in others, so as to provide a contrast
• The identity of the important features should remain unchanged under changes in brightness, size, and perspective
• The features should yield a unique pattern for each letter
• The number of proposed features should be reasonably small

Question 13

Perceptual Confusions

Answer 13

When items have many aspects to them features help eliminate confusion
- If things are very distinct from one another, you’re less likely to have a perceptual confusion

Question 14

Which set is more likely to cause perceptual confusion? P and R OR P and W

Answer 14

P and R are likely to cause perceptual confusion as they differ on a single feature

Question 15

Distinctive Features

Answer 15

Features that help distinguish very similar patterns from one another

Question 16

In cats, what are some distinctive features?

Answer 16

Eye color, fur color, nose color, fur pattern

Question 17

Egeland (1975)

Answer 17

An effective method for emphasizing a distinctive feature is to initially make it a different color from the rest of the pattern and then gradually change it back to the original color

Question 18

Why does Egeland (1975) work for pre-k children?

Answer 18

The color provides a contrast and allows children to distinguish the letters better.
1. Enables the children to learn the distinctive features even when they are no longer highlighted
2. Enables them to learn the features w/o making many errors

Question 19

Faces - General Distinction

Answer 19

This is a face

Question 20

Face - Intermediate Distinction

Answer 20

This is a face of someone with ____ heritage

Question 21

Face - Specific Distinction

Answer 21

This is my mother’s face

Question 22

Hugenberg et al. (2007)

Answer 22

Asked participants to perform a facial recognition task and were either informed that it would be more difficult to recognize differences in the faces of those who have a different ethnic background from their own, or not

Question 23

Results of Hugenberg et al. (2007)

Answer 23

Participants who were informed about the difficulties did better than those who were not informed, because they realized they needed to focus on SPECIFIC DISTINCTIONS rather than INTERMEDIATE DISTINCTIONS

Question 24

Why does being informed matter in Hugenberg et al’s experiment?

Answer 24

By priming participants that the task is challenging, these participants will focus on the task more

Question 25

What are some problems with using features?

Answer 25

- Features, by themselves, are not very informative pattern. - A list of features ignores the relationship between those features (think of M vs. W)