Abstract
Individuals are highly sensitive to statistical regularities in their visual environment, even when these patterns do not reach conscious awareness. For example, substantial savings in search time is observed when some or all aspects of distractor/target configurations repeat (e.g., Chun & Jiang, 1998; Song & Jiang, 2005). Moreover, when encoding and subsequently recognizing photographs, scanpaths tend to repeat over multiple viewings (e.g., Foulsham & Underwood, 2008). Here, we examine whether oculomotor behavior is systematically altered when images and distractor/target configurations rarely repeat, but target location on an initial trial always predicts the general location of a target on the subsequent trial (e.g., a target in the lower left quadrant on trial N means the target will appear somewhere in the upper right quadrant on trial N+1). Participants search for a target through a gaze contingent window in a display consisting of multiple distractors and provide a discrimination response (target present/absent). Critically, no visual information is presented at fixation to bias initial eye movements. The results of Experiment 1 are consistent with the adaptive scanning hypothesis (Myers & Gray, 2010) in that participants demonstrate a search time reduction based on the learning of the statistical regularity and this seems primarily due to a) the same general scanpath repeating and b) increased efficiency of search due to fewer fixations and lesser dwell in each quadrant across trials. Importantly, however, this effect is not attributable to serial scanning order as detection of a target on N does not alter the likelihood that the correct quadrant will be fixated first on N+1. In follow-up experiments, participants are forced to vary their search order strategy to determine whether a bias based on the learned regularity would emerge. Collectively these experiments influence our understanding of the manner in which learned regularities affect oculomotor behavior.
Meeting abstract presented at VSS 2013