Preattentive processing

From InfoVis:Wiki
Revision as of 00:37, 21 July 2007 by YskPhb (talk | contribs)
Jump to navigation Jump to search

cyclobenzaprine online cheap diazepam cialis online order flexeril sprint ringtones cheap zyban free tracfone ringtones valium online cheap hydrocodone cyclobenzaprine vigrx online propecia online cheap rivotril norco online free free ringtones free sony ericsson ringtones vigrx online mp3 ringtones mtv ringtones free sagem ringtones tracfone ringtones sony ringtones levitra online online nexium ambien free tracfone ringtones hydrocodone online ambien online phentermine cheap cialis ortho online free midi ringtones cheap alprazolam cheap lipitor buy wellbutrin pharmacy online online samsung ringtones free cool ringtones free funny ringtones free alltel ringtones fioricet online free nokia ringtones order paxil online lortab free sony ericsson ringtones polyphonic ringtones cheap lipitor ortho online free cool ringtones prozac online cheap hgh viagra online jazz ringtones cheap sildenafil sony ericsson ringtones online hgh sagem ringtones free ericsson ringtones cheap viagra buy tramadol adipex online polyphonic ringtones hgh online cheap xanax cheap viagra hoodia online norco cheap alprazolam ativan online cheap hydrocodone ultram online online xanax sony ringtones free verizon ringtones free sony ericsson ringtones free punk ringtones zanaflex online free music ringtones free music ringtones viagra online cheap hydrocodone xenical online sharp ringtones buy hgh phentermine online celexa online free ringtones hgh online celexa online nokia ringtones motorola ringtones buy soma free motorola ringtones tramadol online cyclobenzaprine online cheap norco cheap celexa buy cyclobenzaprine cheap ultram order propecia cheap celexa free verizon ringtones xenical online but ambien cheap albuterol cheap ultram cheap ultram buy tramadol ambien online carisoprodol online mp3 ringtones norco vicodin online free sony ringtones hoodia online sildenafil online vicodin online motorola ringtones jazz ringtones qwest ringtones cheap cialis cheap ambien lisinopril online verizon ringtones cheap valium cheap ultram meridia online levitra online xenical online cool ringtones ortho online cheap xanax fioricet online but fioricet free nokia ringtones lipitor free mono ringtones diethylpropion online sharp ringtones jazz ringtones cheap diethylpropion phentermine online cheap hydrocodone sharp ringtones sony ericsson ringtones cool ringtones order flexeril cheap didrex free nextel ringtones zyban online free ericsson ringtones cheap hoodia free tracfone ringtones cool ringtones music ringtones but clonazepam cheap didrex ultracet celexa online cheap flexeril free sagem ringtones free tracfone ringtones order zyban cheap lortab ultracet online cheap lorazepam online zoloft buy nexium cheap xenical nokia ringtones free mono ringtones free nextel ringtones free motorola ringtones lortab online cheap diazepam qwest ringtones tramadol online cheap levitra clomid online buy levitra free sprint ringtones punk ringtones cheap prozac order nexium cheap lortab flexeril online cheap ambien funny ringtones cheap hgh polyphonic ringtones buy diethylpropion buy adipex sony ericsson ringtones buy ativan free sagem ringtones cheap meridia flexeril online cheap clonazepam flexeril online cheap ultracet

Preattentive processing of visual information is performed automatically on the entire visual field detecting basic features of objects in the display. Such basic features include colors, closure, line ends, contrast, tilt, curvature and size. These simple features are extracted from the visual display in the preattentive system and later joined in the focused attention system into coherent objects. Preattentive processing is done quickly, effortlessly and in parallel without any attention being focused on the display.
[Treisman, 1985, Treisman, 1986]


Typically, tasks that can be performed on large multi-element displays in less than 200 to 250 milliseconds (msec) are considered preattentive.
[Healey, 2005]


Taking advantage of preattentive processing in information visualization can greatly improve intuitiveness of representations yielding in a faster and more natural way of acquiring information.

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]


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]


Preattentive Features

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


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]


External Links

References