Chapter 4: Object Recognition

Object/Pattern Recognition: Making sense of stimulus energyProcess: Bottom-Up vs. Top-down – see ambiguous imageDirect vs. Constructive Perception

Gestalt Organizational PrinciplesTheories of Pattern RecognitionGestalt: Stimulus information combined

with innate organizing principles of sensory systems. Need examples of principles (proximity, similarity, common fate, closure, and overriding principle of Pragnanz

Theories of Pattern Recognition: Cont.

• 2. Template Matching: external pattern matched to stored internal representation

• 3. Feature Analysis: constructing pattern based on combinations of primitive features

• 4. Prototype Matching: Stored representation that acts of ‘exemplar’ of entire category of patterns.

• 5. Geon Theory: Recognition based on geometric primitives

Stored canonical view

Template matching

• But what about K K K K K K

Prototype matching

• Central tendency: average representation• Attribute frequency: modal representation

Selfridge (1959) Pandemonium model

PDP word recognition model

• Geon forms using basic cylinder shape

Expertise and Pattern Recognition

• Chase and Simon (1970’s): studies with chess experts

• Expertise corresponds to more efficient processing of increasingly larger, more meaningful patterns.

• Expansion of working memory capacity – Long-term working memory

Chess patterns