How the Visual Cortex Recognizes Objects The Tale

How the Visual Cortex Recognizes Objects, The Tale of the Standard Model Greg Mc. Chesney Texas Tech University Greg. mcchesney@ttu. edu Jan 23, 2009 CS 5331: Autonomous Mobile Robots 1

Talk Outline ¡ Overview of paper l l l ¡ Jan 23, 2009 Discuss how object recognition works Discuss experiments performed Discuss the Standard Model Questions from Class CS 5331: Autonomous Mobile Robots 2

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 CS 5331: Autonomous Mobile Robots 3

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 CS 5331: Autonomous Mobile Robots 4

Experiments ¡ Knowledge gained from tests with: l Monkeys Object recognition of a paper clip ¡ QUESTION: How do they get data from monkeys? ? ? ¡ l l Humans ¡ Jan 23, 2009 Experimental lesions into the monkeys ¡ Source: http: //www. vision. caltech. edu/CNS 179/p apers/tanaka 97. pdf New non evasive procedures to gather data CS 5331: Autonomous Mobile Robots 5

The Standard Model by which to represent cortex ¡ 2 D images can be learned in 1 view ¡ 3 D images can be many views ¡ Model in 2 parts ¡ l l Jan 23, 2009 Scale and position invariance View-invariant using view-tuned neurons CS 5331: Autonomous Mobile Robots 6

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More Standard Model Selectivity is required! ¡ Representation- in cortex ¡ l l l Jan 23, 2009 Faces Places Body Parts CS 5331: Autonomous Mobile Robots 8

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Stand Model Continued Categorization ¡ Identification ¡ Pooling ¡ Max Mechanism ¡ Jan 23, 2009 CS 5331: Autonomous Mobile Robots 10

Questions? ¡ Jan 23, 2009 How does pooling by the maximum operation differ than the linear operation? CS 5331: Autonomous Mobile Robots 11

That’s it! ¡ Jan 23, 2009 Were Done! CS 5331: Autonomous Mobile Robots 12