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

9/21/2011 1

BIONB 4240 September 20, 2011 Gbambele Kone

Overt attention toward oriented objects in free-viewing owls (Harmening 2011)

Authors

• Dr. Hermann Wagner

Chair of the Department of Zoology and Animal Physiology, RWTH Aachen University Undergraduate: University of Tubingen, 1980 Graduate: University of Tubingen, 1986 Focus: Biological information processing in the

• rientation and prey capture behavior of owls
• Dr. Wolf Maximillian Haremening

Postdoctoral fellow at the School of Optometry University of California, Berkeley, Prof. Austin Roorda Undergraduate : RWTH Aachen University, 2005 Graduate Work: RWTH Aachen University, 2008 Focus: Visual psychophysics in humans and birds, hyperacute perception

Authors

 Ohad Ben-Shahar: Department of Computer Science, Ben-

Gurion University of the Negev. Ralph Selig Development Career Chair in Information Sciences

 Julius Orlowski: Previously worked with Wolf Harmening on

the spatial contrast sensitivity of barn owls

PNAS

 Proceedings of the National Academy of Sciences of the

United States of America founded in 1915.

 Impact Factor: 9.771  Eigenfactor: 1.668  Multidisciplinary journal

Visual Salience Saccades

 Ballistic eye movement  Constant eye movement over a scene so that fovea can focus

• n different areas = greater resolution

9/21/2011 2 Saccades in Humans

Yarbus 1967

Common Barn Owl (Tyto alba pratincola)

Why use Owls?

 1) Barn owl eye movements are absent or very small  2) Visual system has been thoroughly studied  3)Barn owls have neural attention mechanisms

Owl Head Movement

 http://www.youtube.com/watch?v=DHTo-4X3940

Experiment Setup: Fovea Determination Experimental Setup: Fovea Determination

9/21/2011 3

Experimental Setup: Room Arrangement Experimental Setup: Room Arrangement

Experimental Setup: Fixation Points Typical Scan Path Results: Fixation Frequency Results: Fixation Time

9/21/2011 4 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

 Owls exhibit visual saliency based on orientation contrast  Establishment of owl as a model organism for the study of

visual information filtering

 Visual saliency is a property found not only in primates, but

birds and provides evidence for the universality of visual processing efficiency

Works Cited



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



Harmening, W . M., Orlowski, J., Ben-Shahar, O. and Wagner, H. (2011). Overt attention toward

• riented 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



Johnen, A., Wagner, H., and Gaese, B.H. (2000). Spatial attention modulates sound localization in 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 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