Teaching:TUW - UE InfoVis WS 2005/06 - Gruppe G3 - Aufgabe 1 - Preattentive Processing

Preattentive Processing

Visualization is so effective and useful because it utilizes one of the channels to our brain that have the highest bandwidths: our eyes. But even this channel can be used more or less efficiently. One special property of our visual system is preattentive processing.[Kosara, 2002]

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One very interesting result of vision research over the past 20 years has been the discovery of a limited set of visual properties that are processed preattentively (i.e. without the need for focused attention). Typically, tasks that can be performed on large multi-element displays in 200 milliseconds or less are considered preattentive.This is because eye movements take at least 200 milliseconds to initiate. Any perception that is possible within this time frame involves only the information available in a single glimpse. Random placement of the elements in the displays ensures that attention cannot be prefocused on any particular location. Observers report that these tasks can be completed with very little effort.[Healey et al., 1996]

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Preattentive Features

Feature	Publication
orientation	Julesz & Bergen [1983]; Wolfe et al. [1992]
length	Triesman & Gormican [1988]
width	Julesz [1985]
size	Triesman & Gelade [1980]
curvature	Triesman & Gormican [1988]
number	Julesz [1985]; Trick & Pylyshyn [1994]
terminators	Julesz & Bergen [1983]
intersection	Julesz & Bergen [1983]
closure	Enns [1986]; Triesman & Souther [1985]
colour (hue)	Nagy & Sanchez [1990]; D'Zmura [1991]; Kawai et al. [1995]; Bauer et al. [1996]
intensity	Beck [1983]; Triesman & Gormican [1988]
flicker	Julesz [1971]
direction of motion	Nakayama & Silverman [1986]; Driver & McLeod [1992]
binocular lustre	Wolfe & Franzel [1988]
stereoscopic depth	Nakayama & Silverman [1986]
3-D depth cues	Enns [1990]
lighting direction	Enns [1990]

A partial list of preattentive visual features, together with references to research that showed they were preattentive.[Chipman, 1996],

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Detecting the Red Object preattentively.[Healey et al., 1996] One visual variable and very easy to find it.

Detecting the Circle preattentively.[Chipman, 1996] It is more difficult but still preantentiv.

Examples of two target detection tasks: (a) target can be detected preattentively because it possess the feature “filled”; (b) target cannot be detected preattentively because it has no visual feature that is unique from its distractors.[Healey et al., 1996]

Region segregation by form and hue: (a) hue boundary is identified preattentively, even though form varies randomly in the two regions; (b) random hue variations interfere with the identification of a region boundary based on form.[Healey et al., 1996]

Conclusion

Any visual processing of that item prior to the act of selection can be called “preattentive”.[Wolfe, Treisma, 2003]

Preattentive processing can help to rapidly draw the focus of attention to a target with a unique visual feature (i.e., little or no searching is required in the preattentive case). [Healey, 2005]

Ressources

• [Kosara et al., 2002] Robert Kosara, Silvia Miksch, Helwig Hauser. Focus+Context Taken Literally IEEE Computer Graphics & Applications (CG&A), Special Issue on Information Visualization, 22(1), pages 22-29. Created at: January/February, 2002.

http://www.kosara.net/papers/Kosara_CGA_2002.pdf .

• [Healey et al., 1996] Healey, C. G., Booth, K. S., and Enns, J. T.. High-Speed Visual Estimation Using Preattentive Processing. ACM Transactions on Human Computer Interaction 3(2), pages 107-135, Created at: 1996.

http://www.csc.ncsu.edu/faculty/healey/download/tochi.96.pdf .

• [Wolfe, Treisma, 2003] Jeremy M Wolfe, Anne Treisma. What shall we do with the preattentive processing stage:

Use it or lose it?, Todd S Horowitz poster presented at the Third Annual Meeting of the Vision Sciences Society. Sarasota. Created at: May, 2003. http://search.bwh.harvard.edu/links/talks/VSS03-JMW.pdf .

• [Healey, 2005] Christopher G. Healey. Perception in Visualization. Department of Computer Science, North Carolina State University. Created at: May, 2005

http://www.csc.ncsu.edu/faculty/healey/PP/index.html#Tri_Cog_Psych:80 .

• [Chipman, 1996] Gene Chipman. Review of High Speed Visual Estimation Using Preattantive Processing (Healy, Booth and Enns). Created at: 1996, Retrieved at: October 24, 2005.

http://www.cs.umd.edu/class/spring2002/cmsc838f/preattentive.ppt#267 .