There are two kinds of Visual Attention :
- Overt Visual Attention: involving eye movements
- Covert Visual Attention: without eye movements (covert fixations aren’t observable). It is important to keep in mind that attention is also able to shift covertly to objects, locations, or even thoughts while the eyes remain fixated.
Changes in spatial attention can occur with the eyes moving, overtly, or with the eyes remaining fixated, covertly (Wright & Ward, 2008).
For example, when a person is driving and keeping their eyes on the road, but then, even though their eyes don’t move, their attention shifts from the road to thinking about what they need to get at the grocery store. The eyes may remain focused on the previous object attended to, yet attention has shifted.
Covert Visual Attention is relative to characteristics of graphical components in the screen independently of the tasks, where Overt Visual Attention data depends to the task that people want to realize on a site. These two data are complementary.
Example of Overt Visual Data (free discovering of eBay homepage) (source : Aga Bojko – Eye Tracking Without Eyes)
Covert Attention prediction by Gweezy (source : Gweezy.com) :
- Hoffman & Subramaniam, 1995
- Kowler E, Anderson E, Dosher B, and Blaser E. (1995) The role of attention in the programming of saccades. Vision Research 35: 1897-1916
- Deubel H, and Schneider W. (1996) Saccade target selection and object recognition: evidence for a common attentional mechanism. Vision Research 36: 1827-1837