What is more important when searching for an object in a real-world scene: foveal vision or extrafoveal vision? This question was assessed in an object search experiment where gaze-contingent display changes created artificial foveal and extrafoveal scotomas. In a 2×3 design, the type of scotoma (foveal vs extrafoveal) was crossed with three different window sizes (radii: 1.6, 2.9, and 4.1 deg). Gaze-centered scotomas were created on the fly by blending the original colored scene photograph and a blurred version of it into each other via a spatial Gaussian weight mask. Overall, search times were longer when the scene outside the gaze-centered aperture was blurred (extrafoveal scotoma) than when the information inside the aperture was blurred (foveal scotoma). There was an additional effect of window size as search times increased (foveal scotoma) or decreased (extrafoveal scotoma) with increasing window size. Based on the eye-movement records, these overall differences could be related to particular sub-processes of search. Compared to the control condition, participants made longer or shorter saccades when searching the scene with a foveal or extrafoveal scotoma, respectively. It is concluded that extrafoveal vision is more important than foveal vision during object search in natural scenes, due to the importance of saccade target selection.
|Number of pages||1|
|Issue number||ECVP Abstract Supp|
|Publication status||Published - 2010|
|Event||Thirty-third European Conference on Visual Perception Lausanne, Switzerland 22 – 26 August 2010 - Lausanne, Switzerland|
Duration: 22 Aug 2010 → 26 Aug 2010