Show Reference: "Object-based saccadic selection during scene perception: Evidence from viewing position effects"

Object-based saccadic selection during scene perception: evidence from viewing position effects. Journal of vision, Vol. 13, No. 5. (01 April 2013), doi:10.1167/13.5.2 by Maciej Pajak, Antje Nuthmann
    abstract = {
                The goal of the present study was to further test the hypothesis that objects are important units of saccade targeting and, by inference, attentional selection in real-world scene perception. To this end, we investigated where people fixate within objects embedded in natural scenes. Previously, we reported a preferred viewing location ({PVL}) close to the center of objects (Nuthmann \& Henderson, 2010). Here, we qualify this basic finding by showing that the {PVL} is affected by object size and the distance between the object and the previous fixation (i.e., launch site distance). Moreover, we examined how within-object fixation position affected subsequent eye-movement behavior on the object. Unexpectedly, there was no refixation optimal viewing position ({OVP}) effect for objects in scenes. Where viewers initially placed their eyes on an object did not affect the likelihood of refixating that object, suggesting that some refixations on objects in scenes are made for reasons other than insufficient visual information. A fixation-duration inverted-optimal viewing ({IOVP}) effect was found for large objects: Fixations located at object center were longer than those falling near the edges of an object. Collectively, these findings lend further support to the notion of object-based saccade targeting in scenes.
    author = {Pajak, Maciej and Nuthmann, Antje},
    day = {01},
    doi = {10.1167/13.5.2},
    issn = {1534-7362},
    journal = {Journal of vision},
    keywords = {attention, bottom-up, objects, saliency, top-down, visual, visual-processing},
    month = apr,
    number = {5},
    pmid = {23547104},
    posted-at = {2013-04-02 08:53:09},
    priority = {2},
    publisher = {Association for Research in Vision and Ophthalmology},
    title = {Object-based saccadic selection during scene perception: evidence from viewing position effects.},
    url = {},
    volume = {13},
    year = {2013}

See the CiteULike entry for more info, PDF links, BibTex etc.

Saccade targets tend to be the centers of objects.

When reading, preferred viewing locations (PVL)—the centers of the distributions of fixation targets---are typically located slightly left of the center of words.

When reading, the standard deviation of the distribution of fixation targets within a word increases with the distance between the start and end of a saccade.

Saccades are thought to be biased toward a medium saccade length; long saccades typically undershoot, short saccades overshoot.

During reading, the further a saccade lands from the center of a word, the greater the probability of a re-fixation.

Pajak and Nuthmann found that saccade targets are typically at the center of objects. This effect is strongest for large objects.