Rensink [Rensink, R. A. . Visual sensing without seeing. Psychological Science, 15, 27–32] has presented evidence suggesting visual changes may be sensed without an accompanying visual experience. Here, we report two experiments in which we monitored observers’ eye-movements whilst they searched for a difference between two simultaneously presented images and pressed separate response keys when a difference was seen or sensed. We first assessed whether sensing performance was random by collecting ratings of confidence in the validity of sensing and assessing (...) gaze location during sensing. Sensing was not random: fixation position and confidence ratings were different when a difference was present compared to catch trials. Furthermore, the uniformity of objects in the images and the type of difference appear to affect seeing and sensing differently, suggesting that these processes are dissociated. The possibility is discussed of a sensing mechanism that increases vigilance toward unconsciously registered differences, particularly changes to scene layout. (shrink)

Perceptual tasks such as object matching, mammogram interpretation, mental rotation, and satellite imagery change detection often require the assignment of correspondences to fuse information across views. We apply techniques developed for machine translation to the gaze data recorded from a complex perceptual matching task modeled after fingerprint examinations. The gaze data provide temporal sequences that the machine translation algorithm uses to estimate the subjects' assumptions of corresponding regions. Our results show that experts and novices have similar surface behavior, such as (...) the number of fixations made or the duration of fixations. However, the approach applied to data from experts is able to identify more corresponding areas between two prints. The fixations that are associated with clusters that map with high probability to corresponding locations on the other print are likely to have greater utility in a visual matching task. These techniques address a fundamental problem in eye tracking research with perceptual matching tasks: Given that the eyes always point somewhere, which fixations are the most informative and therefore are likely to be relevant for the comparison task? (shrink)

Eye movements were recorded during the display of two images of a real-world scene that were inspected to determine whether they were the same or not . In the displays where the pictures were different, one object had been changed, and this object was sometimes taken from another scene and was incongruent with the gist. The experiment established that incongruous objects attract eye fixations earlier than the congruous counterparts, but that this effect is not apparent until the picture has been (...) displayed for several seconds. By controlling the visual saliency of the objects the experiment eliminates the possibility that the incongruency effect is dependent upon the conspicuity of the changed objects. A model of scene perception is suggested whereby attention is unnecessary for the partial recognition of an object that delivers sufficient information about its visual characteristics for the viewer to know that the object is improbable in that particular scene, and in which full identification requires foveal inspection. (shrink)

Complex problem solving is often an integration of perceptual processing and deliberate planning. But what balances these two processes, and how do novices differ from experts? We investigate the interplay between these two in the game of SET. This article investigates how people combine bottom-up visual processes and top-down planning to succeed in this game. Using combinatorial and mixed-effect regression analysis of eye-movement protocols and a cognitive model of a human player, we show that SET players deploy both bottom-up and (...) top-down processes in parallel to accomplish the same task. The combination of competition and cooperation of both types of processes is a major factor of success in the game. Finally, we explore strategies players use during the game. Our findings suggest that within-trial strategy shifts can occur without the need of explicit meta-cognitive control, but rather implicitly as a result of evolving memory activations. (shrink)