Task Dependency of Eye Fixations & The Development of a Portable Eyetracker Jeff Cunningham Senior Research Project Dr. Jeff Pelz Visual Perception Laboratory at the Center for Imaging Science at RIT

Overview u Goals 1.Demonstrate the relationship between eye fixations and the task at hand. 2.Improve the portability of the video eye tracking system currently in use in the Visual Perception Lab. u Results –Methods of data collection and analysis. –What were the factors associated with eye fixations? –About the portable eyetracker. u Conclusions u Questions

Goals u A question of perception –Alfred Yarbus 1960s -- obtrusive instruments. Are Yarbus’ results an artefact of his equipment? –How results obtained with a video eyetracker compare to Yarbus’? u Portable Eye Tracking –The ASL 501 eye tracker is designed to be a portable system. –Use some existing ASL hardware. –Reduce size & weight. –Increase comfort. –  2 hours on batteries.

Task Dependency -- Data Collection u Video eye track 9 subjects. u 3 Tasks –Free Viewing –Memorization –Ages u Collect statistics on fixations. u 3 Images –Doc –Shoe –Ropes

Task Dependency -- Data Collection Doc Shoe Ropes

Task Dependency - Fixations One Subject Free Viewing > 10% % 6 - 8% 4 - 6% 2 - 4% < 2%

Task Dependency -- Fixation Summary

Task Dependency -- ANOVA u General Linear Model w/ 2 Factors: –Image –Task Head Fixations Imagep = 0.14 Task p = 0.00 Image*Taskp = People Fixations Imagep = 0.04 Task p = 0.00 Image*Taskp = 0.05 Object Fixations Imagep = 0.02 Task p = 0.00 Image*Taskp = 0.134

Portable Eye Tracking CamcorderBatteriesCap & Optics ASL Control Box

Portable Eye Tracking Eye Camera IR Illuminator Scene Camera IR Reflective Visor

Portable Eye Tracking u Changes: –Moved to baseball cap. –Swapped in smaller CCD cameras. –Used smaller visor. –Powered by 3 batteries. –Camcorder instead of VCR. u Still the same: ASL control box.

Portable Eye Tracking u Pro’s –Battery time is approx. 3 hours. –Is lighter and smaller. –Is more comfortable. u Con’s –Set-up takes longer. –Eye image is less stable. –Eye image is too large.

Portable Eye Tracking u Yet Remaining –Didn’t have time to do a comparison to the existing eye tracker. –For more stability, move to a new cap. –Move optics for a smaller eye image. –Wire for sound.

Conclusions u Task Dependency –There is a significant change in eye fixation patterns that varies with task. –A dependency on image was not as clear. u Portability –A smaller, lighter, and more comfortable tracker was made. –Battery life is good. –More work needs to be done.

? Questions?