Gaze capture by eye-of-origin singletons: Interdependence with awareness

L. Zhaoping
2012 Journal of Vision  
Where we look in visual tasks is determined by both bottom-up and top-down factors. One theory (Li, 1999a (Li, , 2002 suggests that visual area V1 creates a bottom-up saliency map, guiding gaze through extensive projections to the superior colliculus. V1 is the only visual cortical area that represents the eye of origin of an input and is also least associated with awareness; I therefore predicted that an ocular singleton (i.e., an item only shown to one eye among other items shown to the other
more » ... shown to the other eye) that is perceptually indistinct might nevertheless attract gaze. In visual searches for an orientation singleton target bar among uniformly oriented background bars, an ocular singleton non-target bar, at the same eccentricity as the target from the center of the search display, often captured the first search saccade. The chance of this capture was above 50% (e.g., 75%) when the eccentricity of the singletons was large and luminance did not vary between the bars, and it was below 50% when the eccentricity was smaller and luminance varied. After each search trial, observers reported whether an ocular singleton non-target (which was actually presented in half of the trials) had been shown. When different bars had similar luminance, misses numbered less than 50% and were independent of whether the gaze was captured by the ocular singleton. However, when luminance varied sufficiently between the bars, 50% were missed overall, albeit significantly less for those that captured gaze. The experiments in this work followed the guidelines in the Declaration of Helsinki. Keywords: gaze capture, eye of origin, singleton Citation: Zhaoping, L. (2012). Gaze capture by eye-of-origin singletons: Interdependence with awareness. Journal of Vision, 12(2):17, 1-22, http://www.journalofvision.org/content/12/2/17, Downloaded From: http://jov.arvojournals.org/pdfaccess.ashx?url=/data/journals/jov/932802/ on 08/09/2017 Figure 1. Reduced-size versions of sample visual search stimuli used in Experiment 1a. This studied how a task-irrelevant ocular singleton bar attracts attention in a visual search for an orientation singleton target. The three different dichoptic presentations, monocular (M), dichoptic congruent (DC), and dichoptic incongruent (DI), are the same when left and right eye images are superposed (resembling the perceived image ). An ocular singleton bar was absent in the M condition and was the target in the DC condition. In the DI condition, it was always a background bar, with the same eccentricity as the target, but in the opposite lateral half of the perceived image from the target. Observers were asked to report (by pressing a button) as soon as possible whether the target was in the left or right half of the perceived image. The dichoptic condition and the eye of origin of the target were random in each trial.
doi:10.1167/12.2.17 pmid:22344346 fatcat:dbablmxt5ncejku5snwigdkqvq