Tech Report: Eye movements - a computational study

Rajesh Rao (rao@cs.rochester.edu)
Mon, 17 Mar 1997 22:34:36 -0500

The following report describing a computational model of eye movements
in visual cognition is available for retrieval via ftp.

Keywords: Saccades, spatiochromatic filters, saliency maps, spatial
memory, object-centered maps, reference frames

Comments and suggestions welcome (This message has been cross-posted -
my apologies to those who received it more than once).

-- 
Rajesh Rao                       Internet: rao@cs.rochester.edu
Dept. of Computer Science        VOX:  (716) 275-2527              
University of Rochester          FAX:  (716) 461-2018
Rochester  NY  14627-0226        WWW:  http://www.cs.rochester.edu/u/rao/

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Eye Movements in Visual Cognition: A Computational Study

Rajesh P.N. Rao, Gregory J. Zelinsky, Mary M. Hayhoe, and Dana H. Ballard

Technical Report 97.1 National Resource Laboratory for the Study of Brain and Behavior University of Rochester March 1997

Abstract Visual cognition depends critically on the moment-to-moment orientation of gaze. Gaze is changed by saccades, rapid eye movements that orient the fovea over targets of interest in a visual scene. Saccades are ballistic; a prespecified target location is computed prior to the movement and visual feedback is precluded. Once a target is fixated, gaze is typically held for about 300 milliseconds, although it can be held for both longer and shorter intervals. Despite these distinctive properties, there has been no specific computational model of the gaze targeting strategy employed by the human visual system during visual cognitive tasks. This paper proposes such a model that uses iconic scene representations derived from oriented spatiochromatic filters at multiple scales. Visual search for a target object proceeds in a coarse-to-fine fashion with the target's largest scale filter responses being compared first. Task-relevant target locations are represented as saliency maps which are used to program eye movements. Once fixated, targets are remembered by using spatial memory in the form of object-centered maps. The model was empirically tested by comparing its performance with actual eye movement data from human subjects in natural visual search tasks. Experimental results indicate excellent agreement between eye movements predicted by the model and those recorded from human subjects.

Retrieval information:

FTP-host: ftp.cs.rochester.edu FTP-pathname: /pub/u/rao/papers/tr97.1.ps.Z URL: ftp://ftp.cs.rochester.edu/pub/u/rao/papers/tr97.1.ps.Z

35 pages; 1385K compressed, 6667K uncompressed ------------------------------------------------------------------------- Anonymous ftp instructions:

>ftp ftp.cs.rochester.edu Connected to anon.cs.rochester.edu. 220 anon.cs.rochester.edu FTP server (Version wu-2.4(3)) ready.

Name: [type 'anonymous' here] 331 Guest login ok, send your complete e-mail address as password.

Password: [type your e-mail address here]

ftp> cd /pub/u/rao/papers/ ftp> get tr97.1.ps.Z ftp> bye >uncompress tr97.1.ps.Z >lpr tr97.1.ps =================================================================================