Abstract
There is a substantial amount of evidence indicating that surprising events capture attention. A prototypical experimental paradigm comprises a target which has to be identified within a circular array of distractors. Initially, all possible locations are cued by uninformative placeholders. After a predefined proportion of trials one cue will unexpectedly be presented in a deviating color. It has been shown that such surprising events can immediately capture attention and facilitate task performance. Similar effects have been observed if the target itself was surprisingly colored or accompanied by a motion cue. In contrast, presenting surprising information on a distractor location elicits more errors and longer processing time. The present study was intended to investigate whether unexpected depth cues are also able to immediately capture attention and whether cues in near or far distance differentially modulate behavior. For this purpose, the outlined experimental design was adopted and presented via stereoscopic head-mounted displays. This way a pronounced depth impression could be induced which offered the possibility to display the critical cue in a closer or more distant depth position than the target. In line with previous results both depth cues did capture attention on their first appearance. The accuracy in the critical trial (i.e. first appearance of the depth cue) was superior to the error rates in the trials without cue and was also better than error rates in the remaining trials with cue. Moreover, response times were faster in trials with depth cue and this was already true for the critical trial. No other marked differences between near and far depth cues were observed. The results emphasize that surprising depth information captures attention and thus can influence perceptual processes. However, in contrast to other experimental paradigms, the relative position in depth (near vs. far) does not considerably affect search performance.
Meeting abstract presented at VSS 2017