Abstract
While much of the literature on involuntary attention has been devoted to the conflict between Contingent Capture and Saliency Capture, a further variant has been proposed as Surprise Capture. Surprise Capture is thought as the attraction of attention instigated by expectation-discrepant, surprising, or novel stimuli. Recent eye-tracking experiments have revealed earlier and longer gaze fixations on an unexpected novel singleton color, consistent with Surprise Capture. This was tested via 32 familiarizing search trials including an irrelevant singleton with a constant color followed by a surprise trial, where the singleton color was changed. Other studies showed that the impact of surprising events on task performance varies with the discrepancy between the expected and the actual surprising event. Yet, the effect of different expectation breadths about specific display elements on gaze behavior has not been investigated. Here, we tested the effect of singleton color variations in the familiarization trials and variations of the number of familiarization trials. We predicted a weakening of Surprise Capture with more variation of the singleton colors within familiarization trials and with a lower number of familiarization trials. Results confirmed this prediction and suggested that expectations towards a singleton color become narrower with a higher number of samples and less variation within the samples. In addition, results suggested that expectation strength reached its asymptote relatively fast: After 17 familiarization trials, Surprise Capture was as strong as after 49 familiarization trials. Reducing the number of familiarization trials even more, however, resulted in a significant decrease of Surprise Capture.
Meeting abstract presented at VSS 2018