1. 1 How the Visual Cortex Recognizes Objects, The Tale of the Standard Model Greg McChesney Texas Tech University Greg.mcchesney@ttu.edu Jan 23, 2009 CS5331: Autonomous Mobile Robots

2. 2 Talk Outline  Overview of paper Discuss how object recognition works Discuss experiments performed Discuss the Standard Model  Questions from Class Jan 23, 2009 CS5331: Autonomous Mobile Robots

3. What is the Paper About  Describes how the eye recognizes images  Discusses how cells react to seeing images  Talks about a model to represent how the cortex works Jan 23, 2009 CS5331: Autonomous Mobile Robots3

4. Object Recognition Facts  Recognition is mediated by ventral visual pathway  Believe cortex vital to object recognition  Simple cells respond to oriented bars Jan 23, 2009 CS5331: Autonomous Mobile Robots4

5. Experiments  Knowledge gained from tests with: Monkeys  Object recognition of a paper clip  QUESTION: How do they get data from monkeys??? Experimental lesions into the monkeys  Source: http://www.vision.caltech.edu/CNS179/p apers/tanaka97.pdf Humans  New non evasive procedures to gather data Jan 23, 2009 CS5331: Autonomous Mobile Robots5

6. The Standard Model  Model by which to represent cortex  2D images can be learned in 1 view  3D images can be many views  Model in 2 parts Scale and position invariance View-invariant using view-tuned neurons Jan 23, 2009 CS5331: Autonomous Mobile Robots6

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8. More Standard Model  Selectivity is required!  Representation- in cortex Faces Places Body Parts Jan 23, 2009 CS5331: Autonomous Mobile Robots8

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10. Stand Model Continued  Categorization  Identification  Pooling  Max Mechanism Jan 23, 2009 CS5331: Autonomous Mobile Robots10

11. Questions?  How does pooling by the maximum operation differ than the linear operation? Jan 23, 2009 CS5331: Autonomous Mobile Robots11

12. That’s it!  Were Done! Jan 23, 2009 CS5331: Autonomous Mobile Robots12