Abstract
Stimuli that are briefly presented around the time of a saccade tend to systematically be misperceived in a wrong location. In the total absence of visual references, this mislocalization reveals a uniform shift in the direction of the saccade. When visual references are available, a spatial compression of the stimuli’s apparent locations towards the saccade target location or the endpoint of the saccade is revealed. A lot of research has been devoted on the role of visual references on perisaccadic compression, using a broad range of abstract stimuli on uniform backgrounds. We wanted to test whether saccadic compression also occurs when viewing natural scenes, making saccades between different objects contained in the scene. We presented an image of a natural scene with ample visual references, and asked participants to make a saccade from a fixation object to a target object, both of which were part of the natural scene. Around the time of the saccade, another object of the scene (previously absent) was briefly flashed. It could be presented at one of five possible horizontal and three possible vertical locations. Participants were asked to localize it by touching the screen at its perceived location. The results show a strong compression around the time of the saccade. We compared this finding with a control condition, where participants performed the same task without the references of the natural scene, but only with the fixation, target and flashed objects presented on a blank screen. The magnitude of compression was similar in the two conditions. Our results indicate that the numerous landmarks contained in the natural scene do not aid in the correct localization of a briefly presented flash around the time of a saccade.
Meeting abstract presented at VSS 2015