Revision as of 13:23, 23 November 2009

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., 1996] shows that a discovery of the past 20 years was that there is a limited set of visual properties. 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

Figure 1: 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. [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]

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.

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 {{Quotation|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]}}
-{{Quotation|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]}}
+[Healey et al., 1996] shows that a discovery of the past 20 years was that there is a limited set of visual properties. 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 ==

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