Visual Pattern Recognition

Question 1

Template Matching Theory

Answer 1

• Visual stimulus compared to specific patterns (templates) in memory.
• Identity determined by which template had greatest amount of overlap.
• Real life: # on bottom of check, handwritten notes

Question 2

Feat Analysis Theory

Answer 2

Take into account specific combinations of basic features

• Alphabet: lines (horizontal, vertical, diagonal), curves, intersections
• A = 1 L-slant diagonal, 1 R-slant diagonal, 1 horizontal in b/t
• Strength: No need to store huge # of templates. Variations in size, color, shape irrelevant
• Weakness: don’t take into account context on pattern recognition

Question 3

Pandemonium Exp.

Answer 3

• Feature analysis w/ letters
• stages characterized by activity of “mental demons” that represent whole letters or their basic features.
• activity-> “shouting”
• Image Demon: Detect neural signal from sensory receptors & passes info to Feature Demons
• Feature Demons: 28 (block, cursive, caps, lower-case). Each compare itself to stim from Image Demon; “shout” if match
• Cognitive Demon: reps specific combo of feats (one for lower & uppercase version of each letter).
• Decision Demon: Identifies pattern Which CD is shouting loudest?
• more recognition errors if multiple Cog Demons shouting loudly (E:. F vs O).

Question 4

Recognition by Components

Answer 4

Takes into account specific combinations of basic features

• Simple 3-D shapes called geons (36)
• If geons are basic features, expect more recog failures when:
• (1) geons are removed than when segments of geons are removed.
• Each item presented for brief
  Intervals with equal amount deleted across conditions.
• Task: Name the object
• Result: Ps made 25% more errors
  w/ intersections deleted

Question 5

CAPTCHA

Answer 5

Completely Automated Public Turing test to tell Computers and Humans Apart

Question 6

Data-Driven Processing

Answer 6

Bottom-Up

Pattern recognition is driven by the physical stimulus only

Question 7

Conceptually-Driven Processing

Answer 7

Top-Down

Pattern recognition is also influenced by context and general knowledge