9/21/2011 Authors Overt attention toward oriented objects in - PDF document

9/21/2011 Authors Overt attention toward oriented objects in free-viewing owls (Harmening 2011) BIONB 4240 September 20, 2011 Dr. Hermann Wagner Dr. Wolf Maximillian Haremening Chair of the Department of Zoology and Animal Postdoctoral fellow at the School of Optometry Gbambele Kone Physiology, RWTH Aachen University University of California, Berkeley, Prof. Austin Undergraduate: University of Tubingen, 1980 Roorda Graduate: University of Tubingen, 1986 Undergraduate : RWTH Aachen University, 2005 Graduate Work: RWTH Aachen University, 2008 Focus: Biological information processing in the orientation and prey capture behavior of owls Focus: Visual psychophysics in humans and birds, hyperacute perception Authors PNAS  Ohad Ben-Shahar: Department of Computer Science, Ben-  Proceedings of the National Academy of Sciences of the Gurion University of the Negev. Ralph Selig Development United States of America founded in 1915. Career Chair in Information Sciences  Impact Factor: 9.771  Julius Orlowski: Previously worked with Wolf Harmening on  Eigenfactor: 1.668 the spatial contrast sensitivity of barn owls  Multidisciplinary journal Visual Salience Saccades  Ballistic eye movement  Constant eye movement over a scene so that fovea can focus on different areas = greater resolution 1

9/21/2011 Common Barn Owl ( Tyto alba Saccades in Humans pratincola) Yarbus 1967 Why use Owls? Owl Head Movement  1) Barn owl eye movements are absent or very small  http://www.youtube.com/watch?v=DHTo-4X3940  2) Visual system has been thoroughly studied  3)Barn owls have neural attention mechanisms Experiment Setup: Fovea Experimental Setup: Fovea Determination Determination 2

9/21/2011 Experimental Setup: Room Experimental Setup: Room Arrangement Arrangement Experimental Setup: Fixation Points Typical Scan Path Results: Fixation Frequency Results: Fixation Time 3

9/21/2011 Results: Fixation Speed Future Work  Brain recordings while providing owl with visual stimuli  Visual saliency tests involving color and motion  Ultimately, mechanism behind visual salience could be applied to robots to produce complex yet efficient artificial visual systems Summary Works Cited  Owls exhibit visual saliency based on orientation contrast Ben-Shahar, O. Personal Info: http://www.cs.bgu.ac.il/~obs/home.html  Eye Image: http://aiykasim.blogspot.com/2011/01/what-does-it-mean-to-study.html   Establishment of owl as a model organism for the study of  Harmening, W . M., Orlowski, J., Ben-Shahar, O. and Wagner, H. (2011). Overt attention toward visual information filtering oriented objects in free-viewing barn owls. Proc Natl Acad Sci U S A 108, 8461-6.  Harmening, W . Personal Info: http://www.bio2.rwth-aachen.de/users/wolf/html/wolf.htm  Visual saliency is a property found not only in primates, but Johnen, A., Wagner, H., and Gaese, B.H. (2000). Spatial attention modulates sound localization in  birds and provides evidence for the universality of visual barn owls. JN Physiol 85(2), 1009-1012. Tatler, B.W ., Wade, N.J., Kwan H., Findlay, J.M., Velichkovsky, B.M. (2010). Yarbus, eye processing efficiency  movements, and vision. i-Perception 1, 7-27. Visual Salience Image: http://www.scholarpedia.org/article/Visual_salience   Wagner, H. Personal Info: http://www.bio2.rwth-aachen.de/users/wagner/html/hermann.htm 4