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.

[Ware, 2000; Treisman, 1985]

Healey, et al. [Healey et al., 1996] mention in their paper that only a limited set of visual properties exists. Tasks, which can be accomplished within 200 milliseconds, are considered preattentive because eye movements need this time to initiate. Everything which can be perceived in this short time includes only absconding information. Attention can not be prefocused on a particular position if elements are set random.

Preattentive Features

A list of two-dimensional features that “pop out” during visual search, and a list of authors who describe preattentive tasks performed using the given feature, are listed in the table of the Figure 1. The various properties and the tasks for which the features are used is described in detail in the literature. [Healey et al., 1996]

Figure 1: two-dimensional features [Healey et al., 1996]

Examples

Figure 2: Detecting the Red Object preattentively. [Chipman, 1996] One visual variable is very easy to find it.	Figure 3: Detecting the Circle preattentively.[Chipman, 1996] It is more difficult but still preantentiv.
Figure 4: 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]	Figure 5: 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]

Conclusion

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

• [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, Accessed at: November 05, 2009. http://www.cs.umd.edu/class/spring2002/cmsc838f/preattentive.ppt#267 .

• [Treisman, 1985] A. Treisman. Preattentive processing in vision. Computer Vision, Graphics, and Image Processing, 31:156–177, 1985.

• [Ware, 2000] C. Ware. Information Visualization: Perception for Design. Morgan Kaufmann Publishers, 2000.