Vater Christian, Kredel Ralf, Hossner Ernst-Joachim
Institute of Sport Science, University of Bern, Bern, Switzerland.
University of Bern, Bern, Switzerland.
J Vis. 2017 May 1;17(5):21. doi: 10.1167/17.5.21.
Previous studies of multiple-object tracking have shown that gaze behavior is affected by target collisions and target-distractor crowding. Therefore, in order to experimentally disentangle this collision-crowding confound, we examined events of target collisions with the bordering frame and crowding with distractors. We hypothesized that collisions are particularly demanding for covert attentional processing, whereas crowding particularly challenges peripheral vision. Results show that gaze is located closer to targets when they are crowded, as would be expected to reduce negative crowding effects by utilizing the higher spatial acuity of foveal vision. However, saccades, which interrupt visual information processing, were instead initiated as a function of target collisions with the bordering frame. Consequently, in a dual-task condition that required the detection of target changes, participants more frequently missed changes if they occurred in time intervals around a collision. Based on these results, superior performance should be expected if foveal gaze is optimally anchored among crowded targets and if potential target changes are monitored with peripheral vision. In addition to the implications for further laboratory research of multiple-object tracking, these findings are relevant to a multitude tasks that require the monitoring of several targets and the simultaneous detection of certain events in the visual periphery, as it is commonly the case, for instance, in sports.
以往对多目标跟踪的研究表明，注视行为会受到目标碰撞和目标-干扰项拥挤的影响。因此，为了通过实验区分这种碰撞-拥挤混淆因素，我们研究了目标与边界框碰撞以及与干扰项拥挤的情况。我们假设，碰撞对隐蔽注意加工的要求特别高，而拥挤对周边视觉的挑战尤其大。结果表明，当目标拥挤时，注视点更靠近目标，正如预期的那样，通过利用中央凹视觉较高的空间敏锐度来减少负面拥挤效应。然而，打断视觉信息处理的扫视反而根据目标与边界框的碰撞而启动。因此，在需要检测目标变化的双任务条件下，如果目标变化发生在碰撞周围的时间间隔内，参与者更频繁地错过这些变化。基于这些结果，如果中央凹注视在拥挤目标中得到最佳定位，并且如果用周边视觉监测潜在的目标变化，那么应该会有更好的表现。除了对多目标跟踪的进一步实验室研究有启示外，这些发现还与许多需要监测多个目标并同时检测视觉周边特定事件的任务相关，例如在体育活动中通常就是这种情况。
